In Exercise helps you get in shape for old age, Science News reports:
Exercise training can keep some of these effects at bay. “As soon as you hit 35 or 40, you need to start doing resistance [exercise],” ... “You muscles are being remodeled constantly. “As the muscle gets older … it gets resistant to building up.” So the older people get, the harder they have to work to get — and keep — their gains.
For VO2 max, decreases in maximum oxygen can mean decreased athletic performance. But “if people do high intensity training, that can be delayed five to 10 years,” says Michael Joyner, a physiologist at the Mayo Clinic in Rochester, Minn. Enough exercise can even keep older athletes racing with the pros — as long as they run far enough.
... for elite athletes, peak performance age increased as distance increased. Athletes who compete in short swimming events tended to peak at 20, while ultra-distance cyclists peaked at 39...
WIND: unfortunately my body is giving me clear indications that age 51 is not as good as age 46 and that the trend is a steady degradation.