Exercise is an important part of maintaining a healthy lifestyle. Exercise provides a range of health benefits from body composition improvements, to aid in the ease with everyday activities, reducing disease risk, and improving quality of life, and mental health symptoms. The purpose of this article is to provide insight into how exercise contributes to advantageous adaptations in each of these areas.
In order to lose weight, one must expend more calories than they consume.
One of the more common reasons for exercising includes weight loss. Exercising involves moving the load of one’s body or moving an external load. Both of which require calories to cause muscular contractions to complete desired movements. Depending on the type, duration, and intensity of the activity, the number of calories expended (i.e., calories burned) will vary.
During exercise, previously sedentary adults have increased energy expenditure 8 to 10 times above resting levels, causing considerably more calories to be utilized (Donnelly, et. al., 2004). Additionally, after exercise is complete caloric expenditure is still raised for 1 to 3 hours after the activity, known as excess post-exercise oxygen consumption, which is required for the body to return to its resting state (Donnelly, et. al., 2004). Moreover, long-term exercise adaptations can cause changes in resting metabolic rate, the number of calories expended to complete normal bodily functions during rest. It is evident that the resting metabolic rate can increase by about 8% in response to aerobic training (Donnelly, et. al., 2004).
Strength and Lean Body Mass Improvements
During resistance training, the load placed on specific muscles causes them to adapt to the given demand upon them.
Another common reason for exercising includes improving strength and increasing lean muscle mass. During resistance training, the load placed on specific muscles causes them to adapt to the given demand upon them. Specifically, progressing loads continually increase the amount of stress placed on the muscle, which in turn causes micro-tears and muscle tissue deformation (i.e. damage to myofibrils within a muscle associated with soreness). The muscle then adapts to this by generating new muscle cell growth and increasing the contractile properties of the muscle (NSCA, 2016). Consequently, the muscle increases in size and strength.
Improvements in muscular strength can enhance function and provide ease during everyday life activities. As one age, muscle mass declines unless one participates in regular resistance training to counteract the loss. This loss of muscle makes completing everyday tasks such as carrying groceries, ascending stairs, completing yard work, or carrying heavy items considerably more difficult. Improvements in strength from resistance training aid in one’s ability to partake in these functional tasks (Hunter et. al., 2004).
Bone and Connective Tissue Adaptations
Weight-bearing activity causes new bone formation, increasing the amount of stress it can handle.
Resistance exercise not only has positive benefits on muscle but also promotes beneficial adaptations of bone and connective tissue. At one age they are at increased risk of developing osteoporosis, post-menopausal females in particular are at a higher risk (Kelley et. al., 2001). Osteoporosis is a disease defined by low bone mineral density (Kelley et. al., 2001). Low bone mineral density increases one's risk of a fracture (Kelley et. al., 2001). Increases in muscle strength and mass from resistance training lead to increases in bone mineral density (NSCA, 2016). Additionally, as bone undergoes weight-bearing activity such as resistance training, running, or jumping, it adapts to the stressors experienced by causing the formation of new bone, thus increasing the stress it can handle (NSCA, 2016). Furthermore, resistance training can increase the strength of tendons and ligaments, decreasing injury risk (NSCA, 2016).
Aerobic Exercise, Body Composition, and Cardiorespiratory Improvements
Improvements in cardiorespiratory function augment ease during submaximal exercise bouts.
Exercise, particularly aerobic exercise, can also contribute to body composition changes, as well as enhance the function of the cardiovascular and respiratory systems. Prolonged aerobic training promotes the utilization of fat as a fuel source, therefore reducing body fat (NSCA, 2016). Aerobic exercise also stresses the cardiovascular and respiratory systems through the requirement of delivering oxygen throughout the body to aid in energy production, allowing the continuation of aerobic activity.
The respiratory system adapts to aerobic exercise by increasing the amount of oxygen uptake by the lungs. The oxygen then becomes a component of blood to be moved to working muscles and tissues throughout the body. The cardiovascular system adapts to aerobic exercise by increasing the amount of blood the heart expels with each contraction, hence allowing more oxygen to be moved throughout the body. These, along with other adaptations of the respiratory and cardiovascular systems eventually lead to increased ease during submaximal exercise bouts, such as walking from place to place or climbing a set of stairs.
Improved Flexibility and Decreased Pain
The body becomes accustomed to the range of motion it experiences most often.
Being active also helps one to have improved flexibility and decreased pain during everyday movements. Active individuals tend to be more flexible than nonactive individuals (NSCA, 2016). Although flexibility exercises have a big impact on this outcome, being more active overall involves moving joints throughout their range of motion on a more regular basis. For example, during resistance training, one should complete exercises through their full range of motion. The body becomes accustomed to what it experiences most often, therefore, the more often one moves through a joint’s range of motion, the more ease there will be with this movement.
Additionally, strengthening certain areas of the body may help to reduce pain in other vulnerable areas, such as the low back. Strengthening the core has been shown to decrease incidences of low back pain (Hlaing et. al., 2021). Moreover, general exercise has also shown to have a reduced effect on pain in many areas of the upper body including, the neck, upper back, low back, and shoulders (Andersen et. al., 2010).
Reduction of Disease Risk
Regular physical activity promotes health adaptations to decrease disease risk.
On top of the physiological adaptations that one develops from exercise, exercising helps to reduce the risk of many diseases. These include, but are not limited to, chronic diseases (i.e., type 2 diabetes), coronary heart disease, and certain types of cancer. Regular physical activity has a beneficial effect on insulin sensitivity, thus, improving blood glucose regulation in the prevention of type 2 diabetes (Burr et. al., 2010). In terms of coronary heart disease, physical activity demands the heart to pump more blood, carrying oxygen and other nutrients throughout the body. Therefore, regular physical activity helps to strengthen the heart’s ability to contract and pump oxygenated blood (Tanasescu et. al., 2002). Furthermore, regular physical activity may increase HDL cholesterol (cholesterol protective against coronary heart disease), lower LDL cholesterol (cholesterol that increases the risk of coronary heart disease), and lower blood pressure, all of which may decrease the risk of coronary heart disease (Tanasescu et. al., 2002). Running, weight training, and rowing, have all promoted decreased risk of coronary heart disease (Tanasescu et. al., 2002).
Mental Health Benefits
Exercise has also been linked to positive self-esteem and an increase in self-efficacy.
Exercise also provides benefits to mental health. Exercise can be utilized as a way to relieve stress. Many individuals feel that exercise provides a calming sense that may last for many hours after exercise is completed (Jackson, 2013). This improvement in stress may be a result of the impact that exercise has on the ability to adapt to stressors, as well as its effect on the neurotransmitters dopamine and serotonin that influence one’s mood (Jackson, 2013).
Additionally, exercise on a regular basis has proven to help prevent depression and anxiety through possible mechanisms such as an increase in the release of endorphins and an increase in mitochondrial numbers, an organelle that is responsible for energy production in cells, which also has shown to play an important role in the ability of the brain to adapt to different stressors (Mikkelsen et. al., 2017). Exercise has also been linked to positive self-esteem and an increase in self-efficacy, or the belief that one can succeed at a task (Mikkelsen et. al., 2017). Higher levels of self-efficacy are correlated to a reduction in depressive symptoms and improved quality of life (Mikkelsen et. al., 2017). Lastly, exercise promotes better quality sleep, both of which may improve symptoms associated with certain mental illnesses (Lederman et. al., 2019).
As a concluding thought, exercising provides many benefits that help create a healthy lifestyle and promote quality of life. Therefore, it is important to find physical activities one enjoys to support their goals and provide additional benefits. It's always important to train smart when starting a routine, but remember the benefits are worth it!
Andersen, L. L., Christensen, K. B., Holtermann, A., Poulsen, O. M., Sjøgaard, G., Pedersen, M. T., & Hansen, E. A. (2010). Effect of physical exercise interventions on musculoskeletal pain in all body regions among office workers: a one-year randomized controlled trial. Manual therapy, 15(1), 100-104.
Burr, J. F., Rowan, C. P., Jamnik, V. K., & Riddell, M. C. (2010). The role of physical activity in type 2 diabetes prevention: physiological and practical perspectives. The Physician and sports medicine, 38(1), 72-82.
Donnelly, J. E., Smith, B., Jacobsen, D. J., Kirk, E., DuBose, K., Hyder, M., ... & Washburn, R. (2004). The role of exercise for weight loss and maintenance. Best Practice & Research Clinical Gastroenterology, 18(6), 1009-1029.
Hlaing, Puntumetakul, R., Khine, E. E., & Boucaut, R. (2021). Effects of core stabilization exercise and strengthening exercise on proprioception, balance, muscle thickness and pain-related outcomes in patients with subacute nonspecific low back pain: a randomized controlled trial. BMC Musculoskeletal Disorders, 22(1), 1–998.
Hunter, G. R., McCarthy, J. P., & Bamman, M. M. (2004). Effects of resistance training on older adults. Sports medicine, 34(5), 329-348.
Jackson, E. M. (2013). Stress relief: The role of exercise in stress management. ACSM's Health & Fitness Journal, 17(3), 14-19.
Kelley, G. A., Kelley, K. S., & Tran, Z. V. (2001). Resistance training and bone mineral density in women: a meta-analysis of controlled trials. American journal of physical medicine & rehabilitation, 80(1), 65-77.
Lederman, O., Ward, P. B., Firth, J., Maloney, C., Carney, R., Vancampfort, D., ... & Rosenbaum, S. (2019). Does exercise improve sleep quality in individuals with mental illness? A systematic review and meta-analysis. Journal of psychiatric research, 109, 96-106.
Mikkelsen, K., Stojanovska, L., Polenakovic, M., Bosevski, M., & Apostolopoulos, V. (2017). Exercise and mental health. Maturitas, 106, 48-56.
National Strength and Conditioning Association [NSCA]. (2016). Essentials of strength training and conditioning. (G. Haff & N. T. Triplett, Eds.). Human Kinetics.
Tanasescu, M., Leitzmann, M. F., Rimm, E. B., Willett, W. C., Stampfer, M. J., & Hu, F. B. (2002). Exercise type and intensity in relation to coronary heart disease in men. Jama, 288(16), 1994-2000.