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 Table of Contents  
Year : 2023  |  Volume : 38  |  Issue : 1  |  Page : 3-10

Physiological adaptations of skeletal muscle and bone to resistance training and its applications in orthopedics: A review

1 Department of Orthopaedics, Sarojini Naidu Medical College, Agra, India
2 Department of Orthopaedics, Government Medical College Firozabad, Firozabad, India
3 Department of Physiology, Sarojini Naidu Medical College, Agra, India
4 Department of PMR, King George Medical College, Lucknow, Uttar Pradesh, India

Date of Submission07-Feb-2023
Date of Acceptance15-Mar-2023
Date of Web Publication20-Apr-2023

Correspondence Address:
Mayur Gupta
Department of Orthopaedics, Sarojini Naidu Medical College, 312/12A, Awas Vikas Colony, Sikandara, Agra 282007, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jbjd.jbjd_9_23

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Resistance training is defined as practicing the execution of different physical exercises that steadily upsurges the muscular force production for improving musculoskeletal strength, power, and endurance. It is of several types and utilizes specific equipment that provides gradational weight increases and can direct them toward the aimed muscle group. Physiological adaptations occur in muscles in response to increasing resistance at levels of muscle fibers and neuromuscular motor units. It increases the cross-sectional area of the individual muscle fiber causing muscle hypertrophy, which is expressed as increased diameter, thickness, and strength of the muscle. There is an increase in the number of motor units recruited, the firing rate of each motor unit during a maximal contraction, activation, and force generation by the muscle. Resistance training enhances bone mineral content and density. New bone formation occurs in areas experiencing mechanical strain that exceeds a minimum force level encountered in daily activities. Benefits of resistance training include significant improvements in general health, balance, coordination, physical vigor, and mental well-being. Functional gains occur in terms of boosted joint function and reduced potential for injury due to increased bone, muscle, tendon, and ligament strengths. It has been safely used across a multitude of disorders requiring physical therapy. It plays a credible role in the rehabilitation of orthopedics patients suffering from disabling musculoskeletal weakness after fracture treatment and chronic painful ailments such as osteoarthritis, osteoporosis, rotator cuff tendinopathy, and neck and low back pain. We here present a review of the varied musculoskeletal physiological adaptations seen in the human body in response to resistance training and its applications in orthopedics.

Keywords: Anaerobic performance, bone strength, neuromuscular responses, orthopedics rehabilitation, physiological adaptations, resistance training

How to cite this article:
Pal CP, Agarwal V, Srivastav R, Gupta M, Singh S. Physiological adaptations of skeletal muscle and bone to resistance training and its applications in orthopedics: A review. J Bone Joint Dis 2023;38:3-10

How to cite this URL:
Pal CP, Agarwal V, Srivastav R, Gupta M, Singh S. Physiological adaptations of skeletal muscle and bone to resistance training and its applications in orthopedics: A review. J Bone Joint Dis [serial online] 2023 [cited 2023 Jun 7];38:3-10. Available from: http://www.jbjd.in/text.asp?2023/38/1/3/374439

  Introduction Top

Resistance training denotes practicing the execution of different physical exercises that steadily upsurges the muscular force production for enhancing musculoskeletal strength, power, and endurance. Resistance exercises use the muscles to work against an additional force or weight. It requires specific equipment that provides gradational weight increases and can direct them toward the aimed muscle group. It relies on anaerobic energy synthesis that accumulates lactate in the muscle cells, thereby producing tissue fatigue. Resistance exercises when performed regularly over a period of time under the proper guidance of a certified trainer lead to adaptations in skeletal muscles, which prevent lactate levels from rising to a fatigue-producing threshold.[1]

Conventionally, resistance training has been employed by young healthy adults to enhance sports and athletic renditions. Anaerobic performance shows drastic elevation in sporting athletes following progressive resistance training due to varied physiological adaptations in the musculoskeletal system. Nevertheless, contemporary studies have highlighted the prospective health advantages of counting resistance training with the community fitness programs, such as aiding in the reduction of risk factors associated with osteoporosis, cardiovascular disease, and diabetes.[2],[3]

Clinically rewarding functional outcomes and salubrious improvements in overall wellness, metabolism, fitness, balance, cardiac and joint functions, muscle, tendon, ligament and bone strengths, toughness, and density are the satisfying advantages of properly performed resistance training.[4] The health gains make it a practical intercession in physical therapy. Clinicians regularly see patients with musculoskeletal disabilities with decreased capacity of muscles to engender vigor probably because of lesions or wasting. The inability to perform daily activities by them issues a reason for clinicians to employ the principles of resistance training when scheming treatment plans. The expanse to which resistance training has been exploited in physiotherapy is deficient regardless of the high prevalence of musculoskeletal weakness, due to uncommon prescriptions owing to insufficient knowledge regarding its usefulness in clinicians.

Types of resistance training

Three methods of doing resistance exercises exist

  1. Isotonic exercise: it involves the motion of muscle groups against resistance (e.g., lifting free weights, barbells, dumbbells, exercise using weight machines, resistance bands, suspension equipment, or bodyweight exercises including pushups, squats, chin-ups, and sit-ups).

  2. Isometric exercise: muscle groups are held still in place against resistance (e.g., plank holds, wall sits, holding weighted balls, or bags).

  3. Isokinetic exercise or variable-resistance exercise: it is performed at a fixed speed using an accommodating machine with the resistance matching the muscle force at that speed of movement (e.g., dynamometer and treadmill).

All types of resistance training can be used to firm and strengthen muscles. As the muscle strengthens, the amount of resistance can also progressively increase, encouraging further muscle building and strength. Resistance training can profit every muscle of the body. The fundamental concept is step-by-step loading of a group of muscles by wisely maneuvering the number, duration and repetitions of exercises, and directions of force exertions to accomplish the intended changes in muscle size, strength, power, and endurance.

Principles of resistance training

Outlined in the recommendations of the American College of Sports Medicine

  1. Execute repetitions down to muscular fatigue

  2. Allow recovery by taking rest between sets

  3. Enhance the resistance as the capacity to produce force rises.[5]

According to the guidelines, novice individuals should use loads corresponding to 8–12-repetition maximum in 1–3 sets with 1–3 min rest periods for training 2 or 3 days each week. A total of 8–12-repetition maximum load is the amount of weight that can be lifted through the available range of motion 8–12 times before needing a rest.

We here present a review of the varied musculoskeletal physiological adaptations seen in the human body in response to resistance training and the advantages offered by these changes in different aspects of the life of the general population and the health of orthopedics patients.

Physiological adaptations of muscle

Resistance training provides anabolic stimulus for increasing muscle mass and function in healthy younger,[6] aged,[7] and cachectic[8] populations. It stimulates similar progressive increases in muscle strength-related mechanical performances and absolute workload in all age groups due to neuromuscular adaptations.[9] Increments in muscle mass and muscle hypertrophy are lesser in middle (>50 years) and older age groups compared with young age groups due to multifactorial deficits in ribosomal biogenesis, anabolic hormones, and blunted translational efficiency and capacity with aging.[10] Physiological adaptations occur in muscles in response to increasing resistance during a resistance training program at levels of muscle fibers and neuromuscular motor units.

Muscle fiber adaptations

Resistance training when performed until muscular failure during each resistance exercise shows a greater increase in muscle fiber size, whole muscle thickness, and content of several key contractile myosin heavy-chain (MHC) proteins because of continuously variable transmission of loading forces.[11] Progressive resistance training increases the cross-sectional area[12] of the individual muscle fiber causing muscle hypertrophy, which is expressed as increased diameter, thickness, and strength of the muscle.[13] There is an associated increment in muscle fiber peak power.[14] The increase in the size of muscle is termed hypertrophy. Transient hypertrophy refers to the enlargement felt after a single exercise activity due to fluid accumulation in the intercellular and interstitial spaces of the muscle tissue. Long-term resistance training increases muscle fiber cell size leading to sustainable hypertrophy. Most of the resistance training programs in human studies have demonstrated a rise of 20%–45% in muscle fiber cross-sectional area. Significant muscular hypertrophy and strength are achievable only after a minimum of 4–6 weeks of the resistance training program.[14] Muscle hypertrophy occurring in response to resistance training is because of greater expression of intracellular actin and myosin protein filaments, a rise in their thickness, elevated synthesis of supporting myofibrillar proteins, sarcoplasm, and intercellular connective tissue matrix.[15]

According to genetics, the number of muscle fiber cells is constant in human body. Muscle hyperplasia lacks definite evidence in the literature. High-volume high-intensity resistance training practiced by professional bodybuilders may under conditions of extreme stress or muscle injury stimulates new muscle fiber development from satellite cells,[16] by the longitudinal splitting of relatively large muscle fibers or development of an inherited larger number of small muscle fibers. However, this leads to only a minor contribution in the muscle cross-sectional area increase with muscle fiber hypertrophy playing the major role.[14]

Muscle hypertrophy occurs in proportion to resistance loading[17] due to the deposition of more intracellular myofibrillar proteins.[18],[19] Resistance training leads to skeletal muscle plasticity by changing the rate and type of protein isoform synthesis in the sarcoplasm. MHC isoforms govern the muscle fiber type[18] and shortening velocity.[19] Alterations and enhanced synthesis of MHC protein isoforms along with the addition of more sarcomeres are the basis for muscle hypertrophy.[17] These factors play a key role in contraction dynamics and, hence, are given priority while accessing training outcomes or comparing various training programs.[18] Additionally, resistance training increases the rate of myofibrillar protein synthesis by modulating a complex network of cellular signaling pathways.[20]

Three major types of skeletal muscle fibers exist based on histochemical staining—type I (slow twitch), IIA (fast oxidative), and IIB (fast glycolytic). Resistance training increases the proportion and fiber cross-sectional area of type II A (fast twitch, oxidative, and fatigue resistant) fibers according to the Rose and Rothstein classification. These type IIA fibers can generate 6–10 time greater muscle force compared with type I fibers because of their significantly higher peak power production, shortening velocity, and potential to increase in size.[21] At the cellular level, there is an increase in the intramuscular fuel stores (adenosine triphosphate, phosphocreatine, and glycogen) and enzymes required in their formation (creatine phosphokinase and myokinase). Fast heavy-chain myosin increases, leading to a decrease in twitch contraction time. Basal metabolism rate increases, leading to an increase in muscle movement speed and strength. All these adaptations lead to a cumulative rise in the functional performance of the muscle fibers.

Neuromuscular motor unit adaptations

Following resistance training, there is an increase in the number of motor units recruited and the firing rate of each motor unit during a maximal contraction. Hence, an increased number of motor units firing at a higher frequency facilitate increased activation and force generation by the muscle. An increase in reflex potentiation by enhancing the ability to raise motor neuron excitability during voluntary effort[22] and synchronization by enhancing supraspinal connections from motor cortex directly to spinal motor neurons during steady, voluntary contractions is important neural adaptations to resistance training.

Important neuromuscular responses that occur as a direct result of resistance training are increased voluntary level of activation of muscles, increased discharge and torque development rates of motor units, increased motor unit synchronization, and a decrease in coactivation of antagonist-muscles producing a higher level of muscular strength and force development. Resistance training increases muscular strength in the initial few weeks by developing more efficient neural pathways along the muscle route, learned synchronous recruitment of additional motor units, increased activation of synergistic muscles, and the inhibition of neural protective mechanisms contributing to enhanced muscle’s capability to generate more force at rapid rates.[23]

Physiological adaptations of tendon and ligament

Resistance training escalates tendon and ligament strength and maintains cartilage tissue viability. Their cross-sectional area and strength rise in response to a functional overload by increasing the collagen fibril diameter, covalent cross-links within a fiber of increased diameter, and the number and packing density of collagen fibrils. High loading results in the proportional growth of the connective tissue by building the absolute collagen and proteoglycan content by increasing the gene expression and proteomic profile. Resistance training also increases peritendinous sheath cells, crimp morphology, tendon stiffness, and its capacity to absorb energy until failure.[24]There is a reciprocal decrease in age-associated low-energy absorption, calcification of tendon, and susceptibility to injury.

Physiological adaptations of bone

Resistance training enhances bone mineral content and density. There is an increase in bone cross-sectional area due to an increase in bone mass. New bone formation occurs in the area experiencing mechanical strain that exceeds a minimum force level that is encountered in daily activities. Bone formation is stimulated by using structural exercises that directly and progressively overload particular regions of the skeleton, as the tissues become accustomed to the stimulus, and change the direction of force application and distribution in the skeleton for continuously enhancing stimulus for new bone formation. Resistance training provides the greatest osteogenic effect, increasing bone strength and mineral content, thereby, reducing the risk of osteoporosis and fracture due to fall.[25] When started in old ages, it has the efficacy of increasing or at least slowing the rate of age-related decline in bone mass.[26]

Mechanical local loading of the bone during resistance training regulates bone cell adaptive modeling and remodeling responses and is the primary functional determinant of bone architecture. Dynamic strain environment activates osteocytes to produce osteogenic responses in the form of bone formation by the proliferation of osteoblasts, thereby improving bone’s structural strength with its prevailing loading conditions. Peak strain, maximum strain rate, frequency of strain change, strain distribution, and duration are factors determining the osteogenic potential of resistance loading of bone by mechanotransduction. Resistance training raises serum concentrations of hormones known to stimulate bone formation such as 1,25 dihydroxy vitamin D3 and parathyroid hormone and biomarkers of bone formation such as osteocalcin and bone-specific alkaline phosphatase by elevating the expression status of osteoblasts and bone mesenchymal cells.

Progressive resistance training significantly elevates bone mass in postmenopausal women and is recommended as an adjunct lifestyle approach to osteoporosis treatment.[27] It is the only health intervention that improves body mass and strength while reducing the risk of falls.[28]

Progressive loading during resistance training plays a key role in maximizing peak bone mass achievement in childhood and early adulthood, maintaining the bone mass through the fifth decade, decreasing bone loss with aging and preventing falls and fractures in the elderly. Adaptations occur exclusively in those parts of the skeleton that are exposed to loading stimuli beyond the usual loading conditions and continue only in response to a daily progressively increasing overload. These benefits diminish rapidly and profoundly if exercise is markedly reduced as evident in studies of bed rest, space flight, and spinal cord injury, thereby presenting the most compelling evidence that mechanical loading is essential to bone growth and integrity.[29]

Muscular contractions and other dynamic mechanical forces that develop during resistance training load the bone tissue with strain to which it responds by beginning a process of bone modeling, remodeling and synthesis of protein molecules that are deposited in the extracellular spaces between the bone cells, and forming organic osteoid matrix, which eventually gets mineralized as calcium phosphate nanocrystals. This orderly process of bone mineralization provides rigidity and strength to the skeleton and occurs primarily on the outer surface layer of the bone called periosteum. Bone mineral density shows a positive correlation with the duration of resistance training until the skeleton adapts to the established level of exercise intensity required, as evidenced by an increase in femoral neck bone mineral density of professional footballers by 3.3% across every hour increase in training duration until a maximum of 6 h per week and by 0.7% in those exercising more frequently.[30]

  Discussion Top

Resistance training produces several key physiological adaptations in the musculoskeletal system that are beneficial both to short and long terms when performed regularly. The gradational loading provides power, strength, endurance, coordination, and balance to the human body. Continuously enhancing stimuli for the growth and development of the system is attainable by perpetually progressing in the resistance training program. This creates the ground for surpassing excellence in sporting events as evidenced by professional bodybuilders and athletes who spend years in resistance training programs building strong muscles and bones.

Physiological adaptations seen include muscle hypertrophy, selective transformation to fast twitch muscle fiber type, increase in muscle fiber cross-sectional area, myosin, and actin proteins content; excitability; firing rate; torque development; peak power production; reflex potentiation; synchronization and raised bone mineral density; bone mass; cross-sectional area; thickness; and strength. These changes occur after intracellular biochemical translational responses to resistance-loading stimuli. This finally changes the musculoskeletal system phenotype, making it healthy, strong, and powerful.

The resistance training program offers a multitude of benefits to people of all age groups of either sex irrespective of the baseline body conditions. The body systems physiologically adapt to the exercises in an anabolic constructive and beneficial manner. When performed in the growing adolescent age groups, it leads to general body development that produces a healthy, strong, and enduring adult body. In adults, it leads to growth, proportional to exercise loading in muscles and bones. In older age groups, even though the net increase in growth is lesser in proportion to the adult age groups due to anabolic resistance, a monitored resistance training program helps in improving and maintaining the body strength, balance, and overall quality of life. It helps build strong bones in the young and maintain bone strength in the old. It offers general well-being and functional body prosperity across multitude aspects of life.

Benefits of resistance training in general population

Benefits of resistance training include significant improvements in general health, balance, coordination, physical vigor, and mental well-being. Functional gains occur in terms of boosted joint function and reduced potential for injury due to increased bone, muscle, tendon, and ligament strengths.[5] Frequency of resistance training affects measures of muscle hypertrophy with superior outcomes observed with twice a week schedule compared with once a week.[31]

Aging acts as a significant risk factor for bones and muscles to become fragile over time leading to osteoporosis and sarcopenia. It usually occurs earlier in women soon after menopause. Such people become frail and are more likely to fall and break a bone leading to serious limitations of mobility and independence. Resistance training makes both muscles and bones stronger and improves balance and coordination in them. Healthy old adults can benefit most effectively from a resistance training period of 50–53 weeks, a frequency of three sessions per week, a volume of 2–3 sets per exercise, 7–9 repetitions per set, a intensity from 51% to 69% of 1 Repetition Maximum, a total time under tension of 6 s, and a rest of 120 s and a rest of 2.5 s between repetitions.[32]

Physical function in the active elderly population can be improved by a simple intervention program of resistance training using own body weight with slow movements and plyometric exercises.[33] It uses resistance forces to muscular contractions for building the strength, size, and anaerobic endurance of skeletal muscles. Body muscles work perpetually to overcome the resistance forces encountered, making them healthier and stronger in due course of time counteracting sarcopenia. Bone, being a living tissue, changes over time in response to forces applied to it and becomes denser by building more bone mass impeding osteoporosis.

Resistance training effectively reduces impairment by uprising the effect of force production by the musculoskeletal system since the physiological adaptations are similar in patients with disability and young healthy population. Inconsistency in training intensity and adherence is more responsible for variability in muscular feedback rather than the disabling pathology. It has a favorable role in populations suffering from chronic pain such as low back and neck pain and people with osteoarthritis. It elevates activity level, ability to perform everyday tasks, and societal participation by improving musculoskeletal power, endurance, and force generation.[34] Twelve-week task-specific resistance training (in bed and chair-rise subtasks, such as sliding forward to the end of a chair with the addition of weights) for elderly over 65 years old requiring assistance for activities of daily living leads to increased overall functional ability and decreased rise time required.[35]

Safety of resistance training

It has been safely used across a multitude of disorders requiring physical therapy. Patients having late surgical fracture fixation have reported successful outcomes and no ensuing fractures.[36] Supervised resistance training by a physical therapist at home for 3 months is feasible and safe for hip surgery patients.[37]

Resistance training poses certain risks for older frail adults, particularly while testing shoulder exercises with the arm placed above the head and posterior to the trunk. Prevention and additional precautions are the best treatment for such injury risks. Essentials for injury prevention are individualized appropriate training program prescriptions, use of safe techniques, equipment and protective footwear, regular breathing, warming up and cooling down, use progressive increments in repetitions and resistance after mastering the lifting technique, correct range of motion, and cardiovascular and musculoskeletal fitness.[38]

Blood flow-restricted low load resistance training (20%–30% of 1 Repetition Maximum) is an effective sarcopenia countermeasure in older adults and can prevent age-related decline in function.[39] Older age, male sex, and time spent in weight training per week are independent risk factors for injury.[40] Supervised resistance training results in greater increments in balance, muscle strength, and power than unsupervised programs in older adults.[41] Elderly women can successfully achieve improvements in general fitness and functional capacity through guided resistance training.[42] High mechanical loaded resistance training is contraindicated for patients undergoing musculoskeletal rehabilitation for significant functional deficits. They have shown positive adaptations and clinically significant improvements in muscle strength and hypertrophy from low load resistance training with blood flow restriction.[43]

Profits realized by patients with chronic disabilities after a brief resistance training program require continuation into a regular exercise schedule for augmentation. Reassuring health gains and compliance were observed during a 9-month trial in disabled patients with spinal cord injuries.[44] Progressive resistance training is far more cost-effective in achieving a better health-related quality of life in the long term than uncritically satisfying embracement of impairing complications and subsequent curative treatment. Hence, it should be integrated into an active lifestyle for prolonged benefits.[45] Older individuals can safely tolerate a supervised progressive resistance training program of a significant duration of 80 weeks and successfully maintain residual strength at higher levels than baseline values at 6-month posttraining.[46] Resistance bands result in equal strength gains compared with weights. They are safe, feasible, low cost, and handy home-based practicable exercises easily approachable by patients recovering from specific musculoskeletal impairments.[47]

Applications in orthopedics

Resistance training also plays a major role in postoperative rehabilitation of orthopedic patients. Its usefulness was first recognized by Dr. Thomas Lanier DeLorme while treating military soldiers in the latter years of the second world war.[48] He demonstrated how progressive resistance exercises substantially improved physical function and considerably shortened rehabilitation, even in polio patients. It significantly ameliorates gait and function after multilevel orthopedic surgery in children with cerebral palsy.[49] Resistance exercises of muscles covering the fractured bone should be integrated into the physiotherapy protocol as early as 12–16-week posttreatment to attain preinjury musculoskeletal function. Resistance training is comparable to stretching in terms of improving the range of motion across a joint.[50] It improves pain, function, and sequelae symptoms, normalizes muscle strength deficits, optimizes function, and increases muscle cross-sectional area even many years after a muscle strain injury. However, no structural influence is seen on the scar tissue.[51]

Debilitated geriatric adults recovering from hip fracture surgery can profit by expanding their rehabilitation in a supervised resistance exercises setting, to regain preoperative strength and physical function.[52] In 6 months, it can enhance the quality of life and decrease disability by helping in regaining preinjury ambulatory status by significantly elevating muscle strength, balance, walking speed, and perceived health.[53] Concerns regarding resistance training with high-intensity loads can be discarded by beginning with lower intensity (50% of one repetition maximum for 1–2 weeks) and progressively upgrading to further desirable loads to still achieve functional results.[54]

Resistance training is extremely beneficial to regaining muscular strength after total hip[55] and knee arthroplasty[56] compared with conventional physiotherapy. Postoperative outcomes in terms of functional performance showing satisfying accentuations in patient-reported outcomes represented by perceived ability to engage in activities of daily living, sports, and recreational activities and greater reductions in pain were observed with both pre- and postoperative progressive resistance trainings.[57] Maximizing strength gains by utilization of variable-resistance training in lower extremity rehabilitation of the athletic population can be a game changer in the developing countries with limited resources.[58]

Postmenopausal women with vertebral fractures can gain superior outcomes in terms of pain, mobility, back extensor muscles strength, and quality of life from short-term 6-week supervised resistance training than home-based program.[59] Patients with chronic incomplete spinal cord injury can rapidly gain voluntary function and strength by short-term maximal intensity resistance training.[60] With aging, there is muscle weakness and poor flexibility in abdominal and lower abdominal region (core), lower back, and legs leading to lower back pain syndrome. Resistance training including core muscle strengthening, flexibility, and balance exercises effectively protects against and rehabilitates it[61] while minimizing injury risk.[62] When performed in a periodized functional way, it safely decreases pain and disability, and improves health, quality of life, balance, and physical fitness in females with chronic low back pain.[63] Musculoskeletal strengthening resistance exercises of the lumbar and cervical extensors significantly reduce pain and provide successful objectively measured clinical results for patients suffering from chronic back and neck pain because they are safe to perform and prescribed based on pretreatment evaluation.[64] A total of 12–16 weeks of posterior chain resistance training targeting agonist muscles for hip, lumbar, thoracic, and shoulder extension had statistically significant effects on pain, level of disability, and muscle strength when compared with general exercises for chronic low back pain patients.[65]

Ten weeks of resistance training may increase lean weight by 1.4 kg, basal metabolic rate by 7%, and bone mineral density by 1%–3%, reduce fat weight by 1.8 kg, and provide sustainable health benefits such as effectively reducing low back pain and discomfort associated with arthritis, fibromyalgia, age-linked osteoporosis, and sarcopenia.[66] Resistance training should be prescribed and conducted by patients across the spectrum of knee osteoarthritis severity as it is an effective intervention for decreasing joint pain, cartilage degradation, anxiety, depression, and escalating physical function, muscle strength, and efficacy.[67] It normalizes muscle firing pattern and joint biomechanics. Adjuvant adequate nutrition, calcium and vitamin D supplementation, or hormone replacement therapy in postmenopausal women are a must to gain maximum advantages from the program. Resistance training for 24 sessions over 8–12 weeks improves pain and physical function notably in knee osteoarthritis irrespective of its location or grade.[68]

Rotator cuff tendinopathy, tennis elbow, and osteoporosis patients have shown better functional outcomes following progressive resistance training during which the participants exercise their muscles against some type of resistance that is progressively increased as strength improves.

Patients suffering from low back pain, osteoporosis, osteoarthritis, and hip fractures benefit functionally from high-repetition low-resistance training programs.[69] The program should be adhered to the basic need of the individual body system and progressively upgraded to achieve the desired results successfully.

Clinicians should consider detailed patient education regarding the prospective benefits one can achieve successfully by regularly following up in a guided resistance training program. The program must be preplanned and organized in accordance with the patient musculoskeletal deficits and prescribed only after the patients can execute pain-free active physiotherapy, usually possible at 3–6 months after orthopedic surgery in most fracture patients. Patients should be carefully counseled regarding the precautions and safety measures to be remembered during training and the associated risks of overtraining to avoid any injury. Constant encouragement and appreciation of the patients are necessary to maintain adherence to the program to achieve useful musculoskeletal functions.

Take home messages

  • Resistance training nurtures several useful musculoskeletal physiological adaptations and should be done correctly under the guidance of a certified trainer regularly to achieve long-term perpetual advantages.

  • Benefits of resistance training include significant improvements in general health, balance, coordination, physical vigor, and mental well-being. Functional gains occur in terms of boosted joint function and reduced potential for injury due to increased bone, muscle, tendon, and ligament strengths.

  • It should be prescribed in a more regular mode by the clinicians to fully expose the functional advantages it offers in terms of enhanced activity level and ability to carry out daily activities in patients with musculoskeletal impairments.

  • Resistance training is a safe and efficacious intervention in physical therapy for orthopedic patients with muscle force deficits contributing to their motor disability.

  • The program should be adhered to the basic need of the individual body system and progressively upgraded to achieve the desired results successfully.

  • Financial support and sponsorship


    Conflicts of interest

    There are no conflicts of interest.

      References Top

    Summermatter S, Santos G, Pérez-Schindler J, Handschin C Skeletal muscle PGC-1α controls whole-body lactate homeostasis through estrogen-related receptor α-dependent activation of LDH B and repression of LDH A. Proc Natl Acad Sci U S A 2013;110:8738-43.  Back to cited text no. 1
    Winnett RA, Carpinelli RN Potential health-related benefits of resistance training. Prev Med 2001;33:503-13.  Back to cited text no. 2
    Kraemer WJ, Ratamess NA, French DN Resistance training for health and performance. Curr Sports Med Rep 2002;1:165-71.  Back to cited text no. 3
    Zwolski C, Quatman-Yates C, Paterno MV Resistance training in youth: Laying the foundation for injury prevention and physical literacy. Sports Health 2017;9:436-43.  Back to cited text no. 4
    American College of Sports Medicine. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc 2009;41:687-708.  Back to cited text no. 5
    DeFreitas JM, Beck TW, Stock MS, Dillon MA, Kasishke PR An examination of the time course of training-induced skeletal muscle hypertrophy. Eur J Appl Physiol 2011;111:2785-90.  Back to cited text no. 6
    Law TD, Clark LA, Clark BC Resistance exercise to prevent manage sarcopenia dynapenia. Annu Rev Gerontol Geriatr 2016;36:205-28.  Back to cited text no. 7
    Strasser B, Steindorf K, Wiskemann J, Ulrich CM Impact of resistance training in cancer survivors: A meta-analysis. Med Sci Sports Exerc 2013;45:2080-90.  Back to cited text no. 8
    Phillips BE, Williams JP, Greenhaff PL, Smith K, Atherton PJ Physiological adaptations to resistance exercise as a function of age. JCI Insight 2017;2:e95581.  Back to cited text no. 9
    Brook MS, Wilkinson DJ, Mitchell WK, Lund JN, Phillips BE, Szewczyk NJ, et al. Synchronous deficits in cumulative muscle protein synthesis and ribosomal biogenesis underlie age-related anabolic resistance to exercise in humans. J Physiol 2016;594:7399-417.  Back to cited text no. 10
    Carroll KM, Bazyler CD, Bernards JR, Taber CB, Stuart CA, DeWeese BH, et al. Skeletal muscle fiber adaptations following resistance training using repetition maximums or relative intensity. Sports 2019;7:169.  Back to cited text no. 11
    Martel GF, Roth SM, Ivey FM, Lemmer JT, Tracy BL, Hurlbut DE, et al. Age and sex affect human muscle fibre adaptations to heavy-resistance strength training. Exp Physiol 2006;91:457-64.  Back to cited text no. 12
    Tesch PA Skeletal muscle adaptations consequent to long-term heavy resistance exercise. Med Sci Sports Exerc 1988;20(5 Suppl):S132-4.  Back to cited text no. 13
    Andersen JL, Aagaard P Effects of strength training on muscle fiber types and size; consequences for athletes training for high-intensity sport. Scand J Med Sci Sports 2010;20:32-8.  Back to cited text no. 14
    Stec MJ, Kelly NA, Many GM, Windham ST, Tuggle SC, Bamman MM Ribosome biogenesis may augment resistance training-induced myofiber hypertrophy and is required for myotube growth in vitro. Am J Physiol Endocrinol Metab 2016;310:E652-E661.  Back to cited text no. 15
    Mackey AL, Esmarck B, Kadi F, Koskinen SO, Kongsgaard M, Sylvestersen A, et al. Enhanced satellite cell proliferation with resistance training in elderly men and women. Scand J Med Sci Sports 2007;17:34-42.  Back to cited text no. 16
    Schoenfeld BJ The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res 2010;24:2857-72.  Back to cited text no. 17
    Adams GR, Hather BM, Baldwin KM, Dudley GA Skeletal muscle myosin heavy chain composition and resistance training. J Appl Physiol (1985) 1993;74:911-5.  Back to cited text no. 18
    Pettee D, Staron RS Myosin isoforms, muscle fiber types, and transitions. Microsc Res Tech 2000;50:500-9.  Back to cited text no. 19
    Coffey VG, Hawley JA The molecular bases of training adaptation. Sports Med 2007;37:737-63.  Back to cited text no. 20
    Wilson JM, Loenneke JP, Jo E, Wilson GJ, Zourdos MC, Kim JS The effects of endurance, strength, and power training on muscle fiber type shifting. J Strength Cond Res 2012;26:1724-9.  Back to cited text no. 21
    Carroll TJ, Riek S, Carson RG The sites of neural adaptation induced by resistance training in humans. J Physiol 2002;544:641-52.  Back to cited text no. 22
    Gabriel DA, Kamen G, Frost G Neural adaptations to resistive exercise: Mechanisms and recommendations for training practices. Sports Med 2006;36:133-49.  Back to cited text no. 23
    Brumitt J, Cuddeford T Current concepts of muscle and tendon adaptation to strength and conditioning. Int J Sports Phys Ther 2015;10:748-59.  Back to cited text no. 24
    Bolam KA, van Uffelen JG, Taaffe DR The effect of physical exercise on bone density in middle-aged and older men: A systematic review. Osteoporos Int 2013;24:2749-62.  Back to cited text no. 25
    Gomez-Cabello A, Ara I, González-Agüero A, Casajús JA, VicenteRodríguez G Effects of training on bone mass in older adults. Sports Med 2012;42:301-25.  Back to cited text no. 26
    Zhao R, Zhao M, Xu Z The effects of differing resistance training modes on the preservation of bone mineral density in postmenopausal women: A meta-analysis. Osteoporos Int. 2015;26:1605-18.  Back to cited text no. 27
    Kohrt WM, Bloomfield SA, Little KD, Nelson ME, Yingling VR; American College of Sports Medicine. American College of Sports Medicine position stand: Physical activity and bone health. Med Sci Sports Exerc 2004;36:1985-96.  Back to cited text no. 28
    Giangregorio L, Blimkie CJ Skeletal adaptations to alterations in weight-bearing activity: A comparison of models of disuse osteoporosis. Sports Med 2002;32:459-76.  Back to cited text no. 29
    Karlsson MK, Magnusson H, Karlsson C, Seeman E The duration of exercise as a regulator of bone mass. Bone 2001;28:128-32.  Back to cited text no. 30
    Schoenfeld BJ, Ogborn D, Krieger JW Effects of resistance training frequency on measures of muscle hypertrophy: A systematic review and meta-analysis. Sports Med 2016;46:1689-97.  Back to cited text no. 31
    Borde R, Hortobágyi T, Granacher U Dose-response relationships of resistance training in healthy old adults: A systematic review and meta-analysis. Sports Med 2015;45:1693-720.  Back to cited text no. 32
    Watanabe Y, Tanimoto M, Oba N, Sanada K, Miyachi M, Ishii N Effect of resistance training using bodyweight in the elderly: Comparison of resistance exercise movement between slow and normal speed movement. Geriatr Gerontol Int 2015;15:1270-7.  Back to cited text no. 33
    Capodaglio P, Capodaglio Edda M, Facioli M, Saibene F Long-term strength training for community-dwelling people over 75: Impact on muscle function, functional ability and life style. Eur J Appl Physiol 2007;100:535-42.  Back to cited text no. 34
    Alexander NB, Galecki AT, Grenier ML, Nyquist LV, Hofmeyer MR, Grunawalt JC, et al. Task-specific resistance training to improve the ability of activities of daily living-impaired older adults to rise from a bed and from a chair. J Am Geriatr Soc 2001;49:1418-27.  Back to cited text no. 35
    Murdoch A, Taylor N, Dodd K Physical therapists should consider including strength training as part of fracture rehabilitation. Physical Therapy Reviews 2004;9:51-9.  Back to cited text no. 36
    Mangione KK, Craik RL, Tomlinson SS, Palombaro KM Can elderly patients who have had a hip fracture perform moderate- to high-intensity exercise at home? Phys Ther 2005;85:727-39.  Back to cited text no. 37
    Sousa N, Mendes R, Monteiro G, Abrantes C Progressive resistance strength training and the related injuries in older adults: The susceptibility of the shoulder. Aging Clin Exp Res. 2014;26:235-40.  Back to cited text no. 38
    Yasuda T Selected methods of resistance training for prevention and treatment of sarcopenia. Cells 2022;11:1389.  Back to cited text no. 39
    Grier T, Brooks RD, Solomon Z, Jones BH Injury risk factors associated with weight training. J Strength Cond Res 2022;36:e24-30.  Back to cited text no. 40
    Lacroix A, Hortobágyi T, Beurskens R, Granacher U Effects of supervised vs. unsupervised training programs on balance and muscle strength in older adults: A systematic review and meta-analysis. Sports Med 2017;47:2341-61.  Back to cited text no. 41
    Filho MM, Venturini GRDO, Moreira OC, Leitão L, Mira PAC, de Castro JBP, et al. Effects of different types of resistance training and detraining on functional capacity, muscle strength, and power in older women: A randomized controlled study. J Strength Cond Res 2022;36:984-90.  Back to cited text no. 42
    Ladlow P, Coppack RJ, Dharm-Datta S, Conway D, Sellon E, Patterson SD, et al. Low-load resistance training with blood flow restriction improves clinical outcomes in musculoskeletal rehabilitation: A single-blind randomized controlled trial. Front Physiol 2018;9:1269.  Back to cited text no. 43
    Hicks AL, Martin KA, Ditor DS, Latimer AE, Craven C, Bugaresti J, et al. Long-term exercise training in spinal cord injury: Effects on strength, arm ergometry, performance and psychological well-being. Spinal Cord 2003;41:34-43.  Back to cited text no. 44
    Taylor NF, Dodd KJ, Damiano DL Progressive resistance exercise in physical therapy: A summary of systematic reviews. Physical Therapy 2005;85:1208-23  Back to cited text no. 45
    Sherk KA, Bemben DA, Brickman SE, Bemben MG Effects of resistance training duration on muscular strength retention 6-month posttraining in older men and women. J Geriatr Phys Ther 2012;35:20-7.  Back to cited text no. 46
    Lopes JSS, Machado AF, Micheletti JK, de Almeida AC, Cavina AP, Pastre CM Effects of training with elastic resistance versus conventional resistance on muscular strength: A systematic review and meta-analysis. SAGE Open Med 2019;7:2050312119831116. Erratum in: SAGE Open Med. 2020 Sep 9;8:2050312120961220.  Back to cited text no. 47
    Todd JS, Shurley JP, Todd TC, Thomas L DeLorme and the science of progressive resistance exercise. J Strength Cond Res 2012;26:2913-23.  Back to cited text no. 48
    Seniorou M, Thompson N, Harrington M, Theologis T Recovery of muscle strength following multi-level orthopaedic surgery in diplegic cerebral palsy. Gait Posture 2007;26:475-81.  Back to cited text no. 49
    Afonso J, Ramirez-Campillo R, Moscão J, Rocha T, Zacca R, Martins A, et al. Strength training versus stretching for improving range of motion: A systematic review and meta-analysis. Healthcare (Basel) 2021;9:427.  Back to cited text no. 50
    Bayer ML, Hoegberget-Kalisz M, Svensson RB, Hjortshoej MH, Olesen JL, Nybing JD, et al. Chronic sequelae after muscle strain injuries: Influence of heavy resistance training on functional and structural characteristics in a randomized controlled trial. Am J Sports Med 2021;49:2783-94.  Back to cited text no. 51
    Trafton P Extended physical therapy with progressive resistance training improved function in frail elderly patients with hip fracture. J Bone Joint Surg Am 2005;87:466.  Back to cited text no. 52
    Binder EF, Brown M, Sinacore DR, Steger-May K, Yarasheski KE, Schechtman KB Effects of extended outpatient rehabilitation after hip fracture: A randomized controlled trial. JAMA 2004;292:837-46.  Back to cited text no. 53
    Mitchelll SL, Stott DJ, Martin BJ, Grant SJ Randomized controlled trial of quadriceps training after proximal femoral fracture. Clin Rehabil 2001;15:282-90.  Back to cited text no. 54
    Mikkelsen LR, Petersen AK, Mechlenburg I, Mikkelsen S, Søballe K, Bandholm T Description of load progression and pain response during progressive resistance training early after total hip arthroplasty: Secondary analyses from a randomized controlled trial. Clin Rehabil 2017;31:11-22.  Back to cited text no. 55
    Husby VS, Foss OA, Husby OS, Winther SB Randomized controlled trial of maximal strength training vs. standard rehabilitation following total knee arthroplasty. Eur J Phys Rehabil Med 2018;54:371-9.  Back to cited text no. 56
    Jørgensen SL, Kierkegaard S, Bohn MB, Aagaard P, Mechlenburg I Effects of resistance training prior to total hip or knee replacement on post-operative recovery in functional performance: A systematic review and meta-analysis. Front Sports Act Living 2022;4:924307.  Back to cited text no. 57
    Lorenz DS Variable resistance training using elastic bands to enhance lower extremity strengthening. Int J Sports Phys Ther 2014;9:410-4.  Back to cited text no. 58
    Çergel Y, Topuz O, Alkan H, Sarsan A, Sabir Akkoyunlu N The effects of short-term back extensor strength training in postmenopausal osteoporotic women with vertebral fractures: Comparison of supervised and home exercise program. Arch Osteoporos 2019;14:82.  Back to cited text no. 59
    Jayaraman A, Thompson CK, Rymer WZ, Hornby TG Short-term maximal-intensity resistance training increases volitional function and strength in chronic incomplete spinal cord injury: A pilot study. J Neurol Phys Ther 2013;37:112-7.  Back to cited text no. 60
    Wewege MA, Booth J, Parmenter BJ Aerobic vs. resistance exercise for chronic non-specific low back pain: A systematic review and meta-analysis. J Back Musculoskelet Rehabil 2018;31:889-99.  Back to cited text no. 61
    Huxel Bliven KC, Anderson BE Core stability training for injury prevention. Sports Health 2013;5:514-22.  Back to cited text no. 62
    Cortell-Tormo JM, Sánchez PT, Chulvi-Medrano I, Tortosa-Martínez J, Manchado-López C, Llana-Belloch S, et al. Effects of functional resistance training on fitness and quality of life in females with chronic nonspecific low-back pain. J Back Musculoskelet Rehabil 2018;31:95-105.  Back to cited text no. 63
    Dreisinger TE Exercise in the management of chronic back pain. Ochsner J 2014;14:101-7.  Back to cited text no. 64
    Tataryn N, Simas V, Catterall T, Furness J, Keogh JWL Posterior-chain resistance training compared to general exercise and walking programmes for the treatment of chronic low back pain in the general population: A systematic review and meta-analysis. Sports Medicine Open 2021;7:17.  Back to cited text no. 65
    Westcott WL Resistance training is medicine: Effects of strength training on health. Curr Sports Med Rep 2012;11:209-16.  Back to cited text no. 66
    Vincent KR, Vincent HK Resistance exercise for knee osteoarthritis. PMR 2012;4(5 Suppl):S45-52.  Back to cited text no. 67
    Turner MN, Hernandez DO, Cade W, Emerson CP, Reynolds JM, Best TM The role of resistance training dosing on pain and physical function in individuals with knee osteoarthritis: A systematic review. Sports Health 2020;12:200-6.  Back to cited text no. 68
    Luan X, Tian X, Zhang H, Huang R, Li N, Chen P, et al. Exercise as a prescription for patients with various diseases. J Sport Health Sci 2019;8:422-41.  Back to cited text no. 69


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