Believe it or not! The notion that exercise (though not too much of it) is good for human health was first suggested by Hippocrates more than 2000 years ago1.
Modern research has seconded the thought that regular physical activity contributes immensely towards health. According to a study conducted in 2006 by the University of British Columbia, there is a direct linear relationship between physical activity and health status of an individual2. Furthermore, during the course of the study, the researchers Warburton et., al. found that level of physical activity of an individual was directly related to the level of his/her health status2;3.
Decades earlier, a famous study (The Framingham study) had identified a similar connection. It had reported an inverse relation between the level of physical activity and risk of developing cardiovascular disease, especially ischemic heart disease4. A number of studies have now identified the role of regular exercise in promoting health and preventing diseases: diabetes, hypertension, ischemic heart disease, obesity, cancer, osteoporosis, etc. to name a few5-8.
Furthermore, physical activity also ensures improved quality of life and longevity4;9-12.
In addition to these health benefits, regular exercise can cause improvements in components of fitness as well: fat loss, gains in lean muscle mass, improved cardiorespiratory (aerobic) fitness, improved functional fitness (muscle power, balance and co-ordination), etc.
Influence of Physical Activity on Musculoskeletal System
Without the musculoskeletal system to support us, we’d collapse like a ‘pack of cards’. Also, it is this system that is of paramount importance to us to be able to assume an erect posture and move from one place to another.
Bones, muscles, nerves, joints, and supporting joint structures like ligaments and cartilage together constitute the musculoskeletal system. Bones and joints form a network of complex levers which are moved about by muscles thus allowing functional tasks.
Functions of the Musculoskeletal System
Some of the functions served by the musculoskeletal system are:
• imparting shape to the human body
• allowing an upright posture; bones support the weight of the body
• performing functional tasks including moving about; without bones, joints and muscles, this wouldn’t be possible
• protecting internal organs, e.g. brain protected by the cranium, rib cage protecting the heart and lungs
• setting up basal metabolism rate; muscles are the most metabolically active tissues
• storing minerals like calcium and phosphates (in bones)
• storing fat which serves as reserve energy (in yellow bone marrow)
• producing red blood cells (in red bone marrow)
Physical Activity and Musculoskeletal System
Resistance training, high intensity aerobic exercise and outdoor sports activities have a definite positive influence on the musculoskeletal system1;2;13-15. Some of the benefits are described below:
• Increased Lean Muscle and Bone Density
That exercise increases lean muscle mass has been known since time immemorial. Increased lean muscle mass translate into numerous advantages for the individual: improved energy metabolism, improved vascularity, improved posture, and improved support to the skeletal framework. Furthermore, exercise has also been shown to strengthen muscles and improve balance and co-ordination. These effects drastically reduce the risk of falls and fractures (esp. crucial in the elderly)15. All in all, increase in lean muscle mass definitely contributes towards improved health.
Physical activity, esp. weight bearing exercise (resistance training) has been shown to be beneficial to bone health15. Exercise not only stimulates bone growth and the accumulation of minerals but also prevents osteoporosis in later life15;16. Borer, in his study on neurohormonal influences on exercise induced growth, observed that high resistance training expresses a ‘growth gene’ in the tissues exercised. Interesting enough, this occurs without the intermediation of growth hormone or in the absence of abundant nutrients17.
Brisk walking (above 6.14 k/h and heart rate: 82.3% of age-specific maximum) provides sufficient mechanical loading on the bones to maintain bone density and prevent osteoporosis in postmenopausal women18.
Similarly, high impact aerobic activity was shown by Welsh and Rutherford to preserve bone density (in addition to strengthening muscles) in postmenopausal women and men over 5013.
• Strong and Supple Joints
Joints are strategic points where 2 or more bones meet with the aim of creating movement (with the help of surrounding muscles). To impart structural integrity as well as stability during movements, joints are supported by a number of structures, viz., surrounding muscles, tendons, ligaments and joint capsules.
As compared to other tissues in the human body, bones, joints and the supporting joint structures are relatively avascular (devoid of blood vessels). However joints, being areas of transfer of intense forces, have to be well lubricated and nourished all the time. This is achieved by means of a natural joint lubricant called the synovial fluid. Exercise acts as the primary stimulus for production of synovial fluid; regular physical activity thus ensures healthy joints.
• Improved Joint Range of Motion
Increased production of synovial fluid keeps joints well oiled, resistant to friction and makes them supple. This, combined with exercise induced improvements in suppleness of ligaments, contributes to an improved joint range of motion.
Mobility exercises like ‘little circles’ with arms or knees for mobilising shoulders and knees respectively cause secretion of synovial fluid with resultant improvement in joint range of motion.
• Improved Metabolic Rates
Even at rest, muscles are the most metabolically active tissue in the human body. Thus, for those looking to lose fat, it makes sense to indulge in resistance training since it will not only ensure gains in lean body mass but will also increase resting metabolic rate (thus burning more calories).
As compared to ‘slow, long-duration aerobics’, intense resistance training tends to not only burn calories during the workout but for a long time after cessation of the exercise session. Schuenke et. al., reported that after a 31 min. resistance training circuit the post-exercise oxygen consumption (EPOC, a measure of metabolic rate) remained elevated for almost 36 hours post workout14.
Exercise or participation in sports can be regarded as the best form of addiction! However, notwithstanding the positive influences of physical activity on health and fitness, there are certain downsides to too much exercise. Overtraining can cause chronic fatigue syndrome and diminish performance19;20. Some researchers have suggested an association of exercise with prevalence of chronic, nonspecific, musculoskeletal pain21. Others have reported the association of sudden death with sports, both competitive as well as non-competitive22;23.
Despite this, it cannot be denied that the ‘risk-benefit ratio’ is heavily stacked in favour of indulging in regular physical activity, exercise or sport of some sort.
A word of advice though! To derive maximum benefits the following should be kept in mind.
To be effective, exercises should be:
• dynamic (as opposed to static)
• over and above a certain intensity; varies depending on the fitness levels of the individual (and, as recommended by most fitness gurus, exercise programs should graded to avoid training plateaus)
• intense enough so that stimulus on the muscles and bones can cause muscle growth and preservation of bone density
• supplemented by nutrients like complex carbohydrates, proteins, calcium and vitamin D3
(1) Paffenbarger RS, Blair SN, Lee IM. A history of physical activity, cardiovascular health and longevity: the scientific contributions of Jeremy N Morris, DSc, DPH, FRCP. International Journal of Epidemiology 2001; 30(5):1184-1192.
(2) Warburton DER, Nicol CW, Bredin SSD. Health benefits of physical activity: the evidence. Canadian Medical Association Journal 2006; 174(6):801-809.
(3) Paffenbarger RS, Jr., Lee IM. Physical activity and fitness for health and longevity. Res Q Exerc Sport 1996; 67(3 Suppl):S11-S28.
(4) Kannel WB, Sorlie P. Some Health Benefits of Physical ActivityThe Framingham Study. Archives of Internal Medicine 1979; 139(8):857-861.
(5) Cavalcanti CB, Barros MV, Meneses AL, Santos CM, Azevedo AM, Guimaraes FJ. Abdominal obesity in adolescents: prevalence and association with physical activity and eating habits. Arq Bras Cardiol 2010; 94(3):350-357.
(6) Misra A, Chowbey P, Makkar BM, Vikram NK, Wasir JS, Chadha D et al. Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management. J Assoc Physicians India 2009; 57:163-170.
(7) Vuori IM. Health benefits of physical activity with special reference to interaction with diet. Public Health Nutr 2001; 4(2B):517-528.
(8) Haapanen N, Miilunpalo S, Vuori I, Oja P, Pasanen M. Association of leisure time physical activity with the risk of coronary heart disease, hypertension and diabetes in middle-aged men and women. Int J Epidemiol 1997; 26(4):739-747.
(9) Buchman AS, Yu L, Boyle PA, Shah RC, Bennett DA. Total daily physical activity and longevity in old age. Arch Intern Med 2012; 172(5):444-446.
(10) Fozard JL. Epidemiologists try many ways to show that physical activity is good for seniors' health and longevity. Review of special issue of Journal of Aging and Physical Activity: The Evergreen Project. Exp Aging Res 1999; 25(2):175-182.
(11) Pentimone F, Del CL. [Why regular physical activity favors longevity]. Minerva Med 1998; 89(6):197-201.
(12) Lee IM, Paffenbarger RS, Jr., Hennekens CH. Physical activity, physical fitness and longevity. Aging (Milano ) 1997; 9(1-2):2-11.
(13) Welsh L, Rutherford O. Hip bone mineral density is improved by high-impact aerobic exercise in postmenopausal women and men over 50 years. European Journal of Applied Physiology and Occupational Physiology 1996; 74(6):511-517.
(14) Schuenke M, Mikat R, McBride J. Effect of an acute period of resistance exercise on excess post-exercise oxygen consumption: implications for body mass management. European Journal of Applied Physiology 2002; 86(5):411-417.
(15) Borer KT. Physical activity in the prevention and amelioration of osteoporosis in women : interaction of mechanical, hormonal and dietary factors. Sports Med 2005; 35(9):779-830.
(16) B+®rard A, Bravo G, Gauthier P. Meta-analysis of the effectiveness of physical activity for the prevention of bone loss in postmenopausal women. Osteoporosis International 1997; 7(4):331-337.
(17) Borer KT. Neurohumoral mediation of exercise-induced growth. Med Sci Sports Exerc 1994; 26(6):741-754.
(18) Borer KT, Fogleman K, Gross M, La New JM, Dengel D. Walking intensity for postmenopausal bone mineral preservation and accrual. Bone 2007; 41(4):713-721.
(19) Budgett R. Overtraining syndrome. British Journal of Sports Medicine 1990; 24(4):231-236.
(20) Morgan WP, Brown DR, Raglin JS, O'Connor PJ, Ellickson KA. Psychological monitoring of overtraining and staleness. British Journal of Sports Medicine 1987; 21(3):107-114.
(21) Reneman MF, de Vries HJ, van den Hengel EJ, Brouwer S, van der Woude LH. Different Level, but a Similar Day Pattern of Physical Activity in Workers and Sick-Listed People With Chronic Nonspecific Musculoskeletal Pain. Arch Phys Med Rehabil 2012.
(22) Marijon E, Tafflet M, Celermajer DS, Dumas F, Perier MC, Mustafic H et al. Sports-related sudden death in the general population. Circulation 2011; 124(6):672-681.
(23) Corrado D, Drezner J, Basso C, Pelliccia A, Thiene G. Strategies for the prevention of sudden cardiac death during sports. Eur J Cardiovasc Prev Rehabil 2011; 18(2):197-208.