How Much Exercise Do I Need?
Any level of physical activity is preferable to no activity. People who engage in even low levels of physical activity appear to have a 20% reduced risk of death compared with those who are sedentary (Gebel 2015; Arem 2015; Garber 2011; NIH 2016; Chodzko-Zajko 2009).
Every 10 years, the United States Department of Health and Human Services publishes updated Physical Activity Guidelines for Americans (DHHS 2008). Their most recent report recommends adults get 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous aerobic activity per week, or an equivalent combination. In addition, strength or resistance training should be performed at least twice per week.
The report also indicates that more substantial health benefits can be obtained with 300 minutes of moderate-intensity activity or 150 minutes of vigorous-intensity activity each week.
Older adults should target 150 minutes of moderate-intensity physical activity per week, or as much as their health will allow. Balance exercises are also important for older adults, to help prevent falls.
Activities such as yoga that develop flexibility, agility, balance, and coordination are also encouraged for all age groups (Gebel 2015; Arem 2015; Garber 2011; NIH 2016; Chodzko-Zajko 2009).
Assessing Cardiorespiratory Fitness
Despite its vital importance, cardiorespiratory fitness is not included in ordinary clinical assessment. An urgent need exists to incorporate aerobic exercise testing alongside traditional measurements of blood pressure, glucose, and cholesterol in individual cardiovascular risk assessments (Kaminsky 2013; Despres 2016; Lee 2010).
Cardiorespiratory fitness can be assessed by measuring maximal oxygen uptake, also known as VO2max–the maximum ability of the body to utilize oxygen during exercise. However, direct measurement of VO2max requires maximal physical effort that is often difficult and may be unsafe for some aging individuals (Gahche 2014; Sartor 2013).
Submaximal exercise testing is a popular and more practical alternative to assess aerobic fitness. This approach estimates VO2max by determining the heart rate response to submaximal intensity exercise such as stair stepping, cycling, or running (or walking) on a treadmill (Sartor 2013; Percia 2016; Gahche 2014). These types of tests are accessible through fitness centers or sports medicine facilities. If you are interested in having a submaximal exercise test, check with your healthcare provider for guidance if you have any health conditions.
In most people, cardiorespiratory fitness can be improved by performing moderate-to-intense physical activity on a consistent basis (Bouchard 2015; Lee 2010).