ACSM'S Health & Fitness Journal:
COLUMNS: Clinical Applications
Disclosure: The author declares no conflicts of interest and does not have any financial disclosures.
Ann M. Swank, Ph.D., FACSM, C.S.C.S., ACSM-CES, ACSM C-PD, is a professor of exercise physiology, co-chair of the Health and Sport Science Department, and director of the Exercise Physiology Laboratory at the University of Louisville. Her research interests are exercise testing and prescription for special populations, with an emphasis on chronic heart failure. She is ACSM Program Director certified, ACSM Clinical Exercise SpecialistSM certified, and a fellow of ACSM.
The U.S. Centers for Disease Control and Prevention estimate that 16% of all deaths annually in the United States are attributable to poor diet and lack of physical activity (2,9). Physical activity induces positive changes in numerous physiological variables and also reduces the risk of cardiovascular disease, functional disability, cognitive decline, and all-cause mortality (3,4,11). Thus, the need to “find a way” to get around barriers preventing individuals from staying active is crucial. This column presents the findings of two recent research articles that present alternative strategies to variables of the exercise prescription: duration and type of activities. These strategies may assist clinicians with helping their patients and clients “find a way” to stay active.
Current physical activity guidelines require that moderate to vigorous physical activity (MVPA) be accumulated in bouts of more than 10 minutes up to 150 minutes per week to achieve health and fitness benefits (7). Given our high rates of sedentary behavior and the impact that this behavior has on our public health, there is a need to determine if bouts of exercise less than 10 minutes but accruing to 150 minutes per week would be of benefit. Glazer and associates (6) examined the relationship between selected cardiovascular risk factors with MVPA accumulated in bouts of either less than 10 minutes or more than 10 minutes. The MVPA was measured by accelerometry, and the study was performed with the third-generation cohort of the Framingham Heart Study.
Moderate physical activity was defined as 3 to 6 METs, and vigorous physical activity was defined as activities requiring greater than 6 METs. The Table provides a list of activities that satisfy this MET requirement (12). It should be noted that the diversity of activities that satisfy this energy level is substantial and should provide any client or patient with lots of options to stay active. The investigators found that regardless of how exercise minutes were accumulated, total MVPA was significantly associated with lower triglyceride levels, lower body mass index, lower waist circumference, lower overall Framingham heart score, and increased high-density lipoprotein cholesterol. The author’s overall conclusion was that compliance with national physical activity guidelines was associated with a statistically significant lower burden from cardiovascular disease risk factors, regardless of how MVPA was accrued.
Clinicians often use the strategy that adding variety to your training program will enhance compliance. This strategy of “finding a way” to increase exercise participation has been much less studied (1,5). However, a recent article by Juvancic-Heltzel and associates (8) sought to address this research question for resistance training. The investigators presented two patterns of resistance training, one involving a high (i.e., 10) number of choices and the other involving only two choices. The amount of exercise performed (time on task and volume lifted), level of enjoyment, and perception of effort during a 20-minute period was then assessed among children (aged 8 to 12 years) and young (aged 18 to 26 years) and older adults (aged ≥60 years). Participants also were given choices of sedentary activities, including puzzles, crosswords, magazines, coloring, and drawing. The investigators found that increasing the varietyof exercise equipment available increased the participation (both time ontask and volume lifted) and enjoymentwithout impacting the perception ofeffort.
The public health implications of a lack of physical activity are profound. Clinicians need to find a way for their clients to incorporate exercise into their lives and, most importantly, continue the activity for a lifetime. Regarding the barrier of “finding the time” to exercise, we now know that 10 minutes or less of MVPA improves many cardiovascular risk factors. In addition, exercise professionals have often touted the benefits of adding variety to their client’s exercise regimen. Although this strategy has not been studied very frequently, recent research suggests that adding variety, at least for resistance training, increases enjoyment and participation across the age groups.
The next Clinical Applications column will address another commonly cited barrier to exercise — that of acute and chronic injury. The authors will give the clinician some practical advice on what to look for in a patient’s/client’s movement patterns to try to predict and prevent the potential for an injury. Preventing injuries may assist the individual in continuing with his or her exercise.
1. Barkley JE, Roemmich JN, Ryan EJ, Bellar D, Bliss MV. Variety of exercise equipment and physical activity participation in children. J Sport Behav. 2011; 34: 137–49.
2. Cook J, Bender B, Senner J, et al. Self-reported physical inactivity by degree of urbanization — United States. 1996. MMWR Morb Mortal Wkly Rep. 1998; 47: 1097–1100.
3. Folson AR, Arnett DK, Hutchinson RG, Liao F, Clegg LX, Cooper LS. Physical activity and incidence of coronary heart disease in middle-aged women and men. Med Sci Sports Exerc. 1997; 29 (7): 901–909.
4. Fried LP, Kronmal RA, Newman AB, et al. Risk factors for 5-year mortality in older adults: the Cardiovascular Health Study JAMA. 1998; 279 (8): 585–92.
5. Glaros N, Janelle M. Varying the mode of cardiovascular exercise to increase adherence. J Sport Behav. 2001; 24: 42–62.
6. Glazer NL, Lyass A, Esliger DW, et al. Sustained and shorter bouts of physical activity are related to cardiovascular health. Med Sci Sports Exerc. 2013; 45 (1): 109–15.
7. Haskell WL, Lee IM, Pate RR, et al. Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Circulation. 2007; 116 (9): 1081–93.
8. Juvancic-Heltzel JA, Glickman EL, Barkley JE. The effect of variety on physical activity: a cross-sectional study. J Strength Cond Res. 2013; 27 (1): 244–51.
9. Mokdad AH, Marks JS, Stroup DF, Gerberding JL. Correction: actual causes of death in the United States, 2000. JAMA. 2005; 293: 293–4.
10. Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee Report. Washington (DC): Department of Health and Human Services; 2008. 683p.
11. U.S. Department of Health and Human Services. Physical Activity and Health: A Report of the Surgeon General. Atlanta (GA): National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention; 1996.
12. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition and Physical Activity. Promoting Physical Activity: A Guide for Community Action. Champaign (IL): Human Kinetics; 1999.