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Woes of the Weekend Warrior

“Those who think they have no time for bodily exercise will sooner or later have to find time for illness.” Edward Stanley (1826-1893)

Key words: master athletes, exercise economy, aerobic, anaerobic, fast twitch muscle fibers, slow twitch muscle fibers

Athletic capacity may be sustained well into advanced age, and many of the physiologic consequences of aging may be mitigated or reversed by regular exercise. Yet only 13 percent of those over 65 years engage in vigorous physical activity at least 3 days a week and obesity rates in this group are increasing. Muscular strength appears to help mitigate the ill effects of obesity and excessive abdominal weight, which showcases exercise to increase muscle strength.

Boomers and the Workplace

What about younger folks, the “Boomers” who are just passing middle age and entering their later years? A study published in May 2011 found that occupations over the past 50 years have shifted dramatically from physical to sedentary jobs that burn fewer calories per day. The study authors suggest that physical activity in the workplace needs to be addressed as part of the overall plan to reduce obesity in younger people. Perhaps incorporating physical activity in the workplace could also reduce the occurrence of “weekend warrior” injuries because workers would be fit.

Master Athletes

There is a growing trend among those middle-aged and older who participate in competitive sports such as cycling, running, golf and swimming. The number of older adults participating in competitive events has increased (at a much greater rate than young adults), and training and nutritional practices have evolved. While they may be well beyond the age of 35 when athletic performance peaks, master athletes over 70 years of age have actually surpassed the winning times for running events at the first Olympic Games held in Athens in 1896. Master athletes have been the focus of scientific scrutiny because they appear to be defying aging. What can we learn from them that will help in our quest for active later years and help prevent injuries?

A profile of the older Master athlete

Aerobic fitness in master athletes (as measured by oxygen consumption) shows some decline, but not nearly as much as in sedentary people. No surprise there perhaps, but notably, blood lipid profiles among master athletes are similar to those of young adults and this substantially decreases their risk of heart disease. They also have better glucose tolerance and lower waist-to-hip ratios than sedentary adults, decreasing their risk for metabolic syndrome and type 2 diabetes. , Master athletes consume more food while maintaining lower body weights than sedentary adults. That is definitely worth noting! How does their metabolism work? It’s something called “exercise economy.”

Exercise economy can be defined as the steady rate of oxygen consumption while exercising at a specific intensity that is below the lactate threshold. Lactic acid buildup leads to fatigue and it is why muscles tire and ache. Exercise economy doesn’t change with age, but oxygen output, heart rate, stroke volume, and peripheral blood flow do. This means that endurance master athletes must preferentially entrain more low-oxygen consuming (anaerobic) muscles (type I, slow twitch). It has been estimated that highly trained endurance athletes have 80% slow twitch muscle fibers. Type II fast twitch muscle fibers use anaerobic fuel to contract and are best suited to short explosive bursts of power. This type muscle fiber tires more easily. Sprinters train for a higher percentage of fast twitch muscle fibers.

Genetically, we are programmed to do best in sports that are either distance endurance types such as marathon running or sprint type sports such as track. However controlled studies have shown that the type of muscle fiber in non-trained individuals can be changed, regardless of their genetic makeup. Recent studies suggest that non-athletic older people who developed muscular strength through exercise conditioning achieve higher degrees of aerobic capacity. A well rounded exercise regimen should include low-intensity exercise utilizing slow twitch muscle fibers – important in maintaining bone strength, balance and flexibility. Included are weight lifting, Tai Chi and Pilates. Additionally cardio workouts to maximize aerobic capacity and cardiac output are needed. This group includes fast walking, running, swimming, cycling and ball sports.

Exercise Smarter As You Get Older

The safety margin for a “dose” of exercise tends to decline with aging. Unfortunately, some aging adults are unwilling to moderate weekend exercise activities and do not train to improve aerobic capacity or cardiac output. The term “weekend warrior” was coined to describe the sedentary individual who overdoes it on physical activities on weekends and either arrives at work on Monday aching, sore or injured. A growing number of middle-aged individuals are pushing to limits that were more appropriate when they were in their twenties. Hence most injuries in older athletes are chronic and overuse injuries that result in diminished flexibility and endurance. In addition, many aging athletes have medical and musculoskeletal problems that mandate tailoring athletic activity to the patient's general health and functional requirements. The best advice is know your body and stay within appropriate limits.

Use techniques that emphasize improved agility, better technical skills, and cardiovascular and musculoskeletal fitness for preventing injury as you get older. Use equipment that you are familiar with and that is safe and age-appropriate. Be careful to warm up and cool down, vary your training regimen and work on balance, coordination and reaction time. These are the essential aspects of injury prevention.

References:

1 Jackson, A.W.; et al.; “Muscular Strength is Inversely Related to Prevalence and Incidence of Obesity in Adult Men” Obesity 2010;18:1988-1995.
2 Church, T.S.; et al.; “Trends Over 5 Decades in U.S. Occupation-Related Physical Activity and Their Associations with Obesity” PLoS One 2011; 6:e19657.
3 Tanaka, H.; Seals, DR; “Endurance Exercise Performance in Masters Athletes: Age-Associaated Changes and Underlying Physiological Mechanisms” J Physiol 2008;586-1:55-63.
4 Rosenbloom, C.; Bahns, M.; “What Can We Learn About Diet and Physical Activity from Master Athletes? Nutrition Today 2005;40:267-272.
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6 Quinn, E.; “Fast and Slow Twitch Muscle Fibers: Does Muscle Type Determine Sports Ability? About.com Guide 2007. http://sportsmedicine.about.com/od/anatomyandphysiology/a/MuscleFiberType.htm.
7 Simoneau, J.A.; et al.; “Human skeletal muscle fiber type alteration with high-intensity intermittent training” Eur J Applied Physiol. 1985;54:250-253.
8 Cadore, E.L. et al.; “Neuromuscular Economy, Strength, and Endurance in Healthy Elderly Men” J. Strength and Conditioning Res. 2011;25:997-1003.
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