Training is no guarantee of health – Mark Sisson at slow twitch
Thinking of doing aerobics for the rest of your life to get in shape? The experience of endurance trainers is a useful guide:
Let’s get one thing straight right off the bat: Endurance training is antithetical to anti-aging. So it amazes me when guys in their 40s and 50s who are training for a marathon or Ironman suggest that doing so will keep them young. It won’t. You may feel like a stud now with your shaved legs and your magic marker biceps tattoos, but endurance training speeds up the aging process almost as fast as watching TV, drinking sodas and eating potato chips. Actually, in some cases, it speeds it up even faster.
There appears to be two pathways to adrenal exhaustion (which was discussed in the recent post on insulin resistance) – through consuming high GI meals (the way of the fat) or by endurance training (the way of the lean):
(…) not only does training and racing tend to produce [cortisol], but even the training meals can produce it. A meal high in sugar and other simple carbohydrates can cause a dramatic rise in cortisol (as part of an insulin-adrenaline cascade). That’s one reason why sugar is known as a powerful immune suppressor.
Chronic high-level training naturally depletes glycogen, which causes the body to release the adrenal hormone cortisol to cannibalize muscle tissue in order to help make new glucose (gluconeogenesis). Besides tearing down valuable muscle, chronic cortisol release carries with it a litany of negative effects. It suppresses immune function, which opens the door not only for short term upper respiratory infections, but may leave the door open for longer term, more serious issues (asthma, cancer, heart disease [which we know has a strong inflammatory component]). Chronic cortisol release also reduces calcium uptake by bones, and it’s not surprising that so many runner/triathletes — especially women — have low bone density. Anti-aging experts will tell you that among elderly, low bone density is a pretty accurate predictor of mortality. Break a hip bone when you’re older and your chances of dying skyrocket.
OK heavy stuff. So what does the author recommend as an ideal fitness program?
I prefer hiking, sprinting and weight-training today.