The 79.1 million American Baby Boomers (those born between 1946 and 1964) now account for twenty-nine percent of the total US population. According to the American Association of Retired People or [AARP], one of the baby boomers officially hits the age of 50 every seven seconds. This is quickly becoming a huge market for personal trainers and coaches, as those over 50 make up the fastest growing segment of the fitness population. According to the International Health, Racquet and Sportsclub Association (IHRSA), older adults are hitting gyms and health clubs at a record rate. As the number of Boomers keeps increasing, it is expected that participation in recreational and competitive sports will continue to increase dramatically over the next few years.
Active adults not only improve their health and put off the changes that characterize normal human aging; they continue to improve their performance as recreational and competitive athletes. The number of healthy, active older individuals is rising due to several factors. Today’s older adults are more affluent, better educated and have more opportunities for leisure activities. As a result, they are living longer and healthier lives that can lead to 20 or 30 years in the status of retirement. In addition, the number of older adults who are active in competitive sports continues to increase. Running USA, a Santa Barbara, California-based not-for-profit organization that tracks trends in distance running, found that the number of race finishers age 55 has increased 136 percent from 1992 to 2007. The number of Boston Marathon finishers age 60 and older has soared from just 65 participants in 1988 to 1,063 in 2008. Active older adults have always had the capacity for success in endurance sports, they just weren’t trained or encouraged to develop their potential.
In 2008, the revised Physical Activity Guidelines for Americans confirmed that regular physical activity reduces the risk of many adverse health outcomes. It has been well established that physical activity can reduce the development of age-related deterioration in many functions related to chronic disease. Older adults who are moderately active can reduce the incidence of cardiovascular disease, diabetes and many other age-related afflictions. The 2008 guidelines state that older adults need a minimum of 30 minutes a day of moderate intensity activity to reap the health benefits. The guidelines emphasize that additional health benefits occur as the amount of physical activity increases through higher intensity, greater frequency, and/or longer duration. What is the option for those that are interested in more than limiting the progression of chronic disease? If additional activity can lead to additional health benefits for older adults, can the same be true for athletic performance?
Fighting the battle against the aging process
Aging is a complex process which involves many factors that interact with one another. It is difficult to isolate physiological aging from genetics, lifestyle behaviors and chronic disease. Determining the extent to which genetic and lifestyle factors influence age-associated functional declines is a hot topic in research. It is likely that a combination of genetic and lifestyle factors contribute to how adults age and also, in how they adapt to an exercise training program.
The cardiovascular system is most directly related to performance for ALL athletes, but becomes more critical in older athletes. As decrease in cardiovascular function is one of the major determinants of reduced exercise capacity associated with aging. There is a decrease in maximal heart rate (HR) due to the decreased responsiveness to circulating catecholmines. In addition, stroke volume (SV) drops 3-4% every decade. In addition, total blood volume and plasma volume are reduced and there is also a small reduction in hemoglobin concentration. All of these factors combine to result in less blood and oxygen delivered to working muscles.
Maximal oxygen consumption (VO2max) is a measure of maximal cardiovascular function. VO2max is limited by 1) the amount of blood delivered to working muscles and 2) the amount of oxygen the muscles can extract from the blood. Since both of these factors decline with normal sedentary aging (see above), it only makes sense that VO2max will decline as well. VO2max in sedentary individuals can drop approximately 1% a year from age 25 to 65yrs with a possible acceleration of this decline over 70 yrs of age. However, it is important to note that the typical decline in body systems may not be related to aging at all. They are related to disuse of the body. The familiar saying of “use it or lose it” holds true as proper exercise training works to prevent the loss of physiological function associated with performance. It has been shown that 65% of decline in VO2max is due to inactivity, NOT aging.
One of the biggest obstacles in maintaining VO2max is that older athletes must train at or near their VO2max in order to prevent the age-related decline. Historically, it was thought that older adults did not have the ability to maintain the same training intensity as when they were younger. More recently is has been shown that developing and maintaining a structured high intensity interval training program can minimize this decrease in VO2max by allowing for a higher capacity to utilize and transport oxygen. Numerous studies show that if INTENSITY is maintained, age related losses in fitness are slight. It has shown that a well planned and executed aerobic training program can augment aerobic power of master’s athletes by as much as 10ml/kg/min over a 3-month period. The key is in maintaining the proper intensity.
A proper training program should contain well-controlled blocks of 3-5 minute high intensity efforts. These cardiovascular efforts need to incorporate major muscle groups. They should be completed on a bicycle or ergometer, elliptical trainer, treadmill or with a whole-body activity such as swimming or cross-country skiing. The high-intensity intervals need to be alternated with intervals of very low intensity recovery. The recommendation is for a 1:1 work to rest ratio, however for those just starting this type of training, a work to rest ration of 1:2 would be more appropriate. These short, periodized blocks of training need to be closely monitored and should only be a few weeks in duration. Older athletes need more recovery not only between the intervals, but also between the high intensity workouts.
It is obvious that no amount of physical activity will stop Father Time. There is evidence that a well planned training program can minimize the physiological effects of biological aging and allow for an increase in overall health and athletic performance.
- American College of Sports Medicine Position Stand. The Exercise and Physical Activity for Older Adults Med. Sci. Sports Exerc July 2009 - Volume 41 - Issue 7 - pp 1510-1530
- Hirofumi Tanaka and Douglas R. Seals, Dynamic exercise performance in master’s athletes: insight into the effects of primary human aging on physiological functional capacity. J Appl Physiol 95:2152-2162, 2003.
- Kenneth W. Hinchcliff and Steven T. Devor, Craig O. Mattern, Margaret J. Gutilla, Darrin L. Bright, Timothy E. Kirby. Maximal lactate steady state declines during the aging process. J Appl Physiol 95:2576-2582, 2003. First published Sep 5, 2003.
- The effects of age and exercise on short term maximal performance: A model based on physiological systems. Jim Martin, PhD, University of Utah.
- Seals DR, Taylor JA, Ng AV, Esler MD. Exercise and aging:autonomic control of the circulation. Med Sci Sports Exerc.1994;26(5):568–76.. 214.