Physical Activity Guidelines and Benefits of Exercise
Mike Purdy, MS
Mike Purdy is a personal trainer at FitClub South in Springfield, IL and has been helping clients reach their fitness goals for over twelve years. He is also an adjunct professor in the Exercise Science Department at Millikin University. He graduated summa cum laude from Millikin University with a bachelor’s degree in Exercise Science Fitness and Sport. During undergrad, he interned with the track and field team where he designed and implemented the strength-training program for sprinters and jumpers. He earned a master’s degree in Exercise Physiology from Southern Illinois University Edwardsville.
Most people likely recognize the need to exercise and be more physically active throughout their lives. However, approximately 80% of adult Americans do not meet the current physical activity guidelines. Furthermore, an estimated $117 billion in annual health care costs are attributed to physical inactivity. Fortunately, it is not all doom and gloom as the number of Americans meeting the guidelines seems to be increasing, though at a slow rate. Why people choose to engage in physical activity or not is an interesting and important topic, but beyond the scope of this article. This article will identify the current activity guidelines and highlight the benefits of exercise, which can serve as a starting point for us in the health and fitness realm to better educate the general population on the importance of physical activity. The current exercise guidelines from the American College of Sports Medicine (ACSM) and the CDC are:
Aerobic exercise at moderate intensity for 150 minutes per week
Muscle strengthening activities involving major muscle groups 2 or more days per week
Admittedly, this is a fairly general recommendation but it does give a couple of target goals (aerobic minutes/week and strength training frequency per week) and allows for individual flexibility. The classic definition of aerobic or cardiorespiratory training is continuous and rhythmic motion, involving large muscles. Examples include: walking, jogging, running, cycling, swimming, rowing, and “ellipticaling.” Muscle strengthening activities, i.e., strength training, involves purposeful movement against an external resistance. Examples include: free weights (barbells, dumbbells, kettlebells), cable or plate loaded machines, and even body weight exercises.
Why is exercise, and physical activity in general, so important? Weight management is typically what comes to mind first. As important as that is, there are many more benefits outside of burning calories. Both cardiorespiratory (cardio) and strength training (aka resistance training) can improve one’s energy or work capacity, making activities of daily living (ADLs) easier. Both can improve serum cholesterol (increase HDL, decrease LDL) and lower resting blood pressure and heart rate. Exercise also has psychological benefits including improved cognitive function, increased confidence, and the potential to reduce depression and anxiety.
In addition to all of the aforementioned benefits, the type of exercise will have specific benefits as well. Cardiorespiratory exercise tends to have a more robust effect on reducing cardiovascular risk factors (reducing resting blood pressure and heart rate). In response to cardio training, the body increases mitochondrial density, oxidative enzymes, and capillary density. These adaptations increase aerobic energy production and oxygen delivery to working muscles. Strength training acts on the musculoskeletal system by increasing the strength and size of the muscles, increasing bone mineral density, and can improve the range of motion of active joints. Furthermore, strength training can improve blood glucose levels and insulin sensitivity, which is important for all, but especially those with or at risk of metabolic disease.
These are some of the specifics. Adding together all of these positive adaptations, few, if any, interventions (drug or otherwise) can boast as many positive benefits as consistent exercise. Highlighting other benefits outside of weight management can better encourage people to start exercising and, perhaps more importantly, keep them consistent. That said, stating all of these benefits can be a bit daunting and may result in information overload when addressing people at first. Simply put, exercise creates an efficient, strong body and mind which not only delays all cause mortality but improves the overall quality of life. It may be tempting to try to hit the guidelines immediately. I would suggest if one is currently sedentary and cleared for exercise, start small and build up gradually. Increasing exercise levels gradually has a number of benefits, especially increasing compliance and consistency. For example, begin with a consistent 2x/week strength training and three 20-minute brisk walking sessions per week for one month. Then, one could progress to 3x/week strength training and three to four 30-minute brisk walking sessions per week and so on. This example does not meet the aerobic goals immediately but over time will build the habit and certainly put one on track to a healthier and better-quality life.
Hopefully the information presented here can be utilized to assist in educating and inspiring people to start making exercise apart of their daily lives. There are a lot of positive aspects to be gained. Before engaging in an exercise program, one should consult a physician to be on the safe side. Fortunately, the ACSM offers a screening document (PAR-Q+) that can help one get started. It can be found at: https://www.acsm.org/docs/default-source/files-for-resource-library/par-q-acsm.pdf
The statistics listed in this article come from Physical Activity Guidelines for Americans 2nd edition. You can read the full work at: https://health.gov/sites/default/files/2019-09/Physical_Activity_Guidelines_2nd_edition.pdf