Most people are at their aerobic and metabolic peaks during their 20s and 30s. As Father Time keeps jogging forward, Mother Nature has her way of pushing back. Then begins the long, slow decline — and if you let it happen, you experience severely diminished aerobic capacity.
If you're much over the age of 40, it will come as no shock that stamina — the ability to sustain prolonged physical or mental effort — diminishes with age. Be that as it may, longevity doesn't have to mean that your gears grind to a halt. Understanding how age is likely to affect your stamina can help you take the best measures for preserving your own.
The Heart (and Lungs) of the Matter
A man's maximum heart rate drops by about a beat per minute annually, according to Harvard Medical School. Meanwhile, his heart's ability to pump blood drops by 5 to 10 percent each decade. Therefore, a 25-year-old's heart can pump 2.5 quarts of blood by the minute while a 65-year-old's heart can't rise above 1.5 quarts. An 80-year-old's heart can only pump about a quart, even if he's healthy as a horse.
In practical terms, this lowered aerobic capacity can cause fatigue and even breathlessness, even with light activity. It doesn't help that in middle age, your blood vessels start to get more brittle as your blood pressure tends to go up, testing the vessels' sturdiness. The blood itself gets thicker, too, so it takes more work for the heart to pump it throughout the body.
Maturity and Muscle Mass
Loss of muscle mass plays another big role in the loss of stamina in sports with aging. After the age of 30, people lose as much as 3 to 5 percent every 10 years, according to Harvard Medical School. Men lose even more muscle mass with aging than women do, and may lose as much as 30 percent during their life spans. Muscle mass propels and stabilizes your skeleton during sports, so obviously as you lose it, your stamina tends to go with it.
This unpleasant fact of life is referred to as sarcopenia and it explains why you can't swing that bat like you used to do. Among the many bummer aspects of sarcopenia are the fact that you've got fewer muscle cells, slower muscle twitch time and lowered muscle force, and that's not to mention that your brain isn't firing as many neurons when your brain tells your muscles to jump.
All the More Reason to Exercise
Aging brings about a decreased aerobic resistance of 45 percent; 40 percent lower hand grip strength; and 70 percent less leg strength. Joint mobility may decline by half and neuromuscular coordination goes down by 90 percent. The Solution: National Institutes of Health recommends 150 minutes a week of moderate intensity exercise such as brisk walking or jogging just to maintain a minimum of fitness. But if you really want to outrun the aging process, you'd do quite well by doubling that and adding some stiff resistance training to build your muscle mass.
In a study at the UAB Center for Exercise Medicine at the University of Alabama at Birmingham, UK, men and women in their 60s and 70s who weigh trained were able to develop muscles as big and strong as those of people in their 40s.
Begin weight training pretty much as you would if you were a young person: three sets of eight to 12 repetitions for each exercise. Choose a weight that brings you to the point of muscle failure by the end of each set and add weight gradually, keeping in mind that you may need one or two days between workouts to recover. Aim for two to three of these strength workouts per week.
It's important to recognize that stamina arises from whole body health. If you want to keep the stamina you've got and gain even more, it's important to train in the four types of exercise: endurance, strength, balance and flexibility.