Aging: Hormones, Training, Risk and Reward

Since
I started this aging series I’ve been getting lots of emails from older
athletes. Perhaps the most frequent comment I hear from them has to do with
recovery. Almost all tell me they recover slower than when they were young. Of
course, as with anything physiological, there is a lot of variance between
athletes when it comes to the age at which this first becomes noticeable. At
age 40 some are already beginning to experience an obvious slowing of recovery
while others in their 50s are seeing little in the way of change. By age 60
it’s usually obvious to those who are paying attention. Recovery rate seems to
be one of the best indicators of actually becoming “old.”

Why
does our recovery after a hard workout take longer with aging? It’s related to something
I’ve discussed in earlier posts – hormones. Hormones regulate our body’s
functions such as metabolism, sleep and mood. They also affect tissue growth
and development – the keys to recovery. As we age we produce less anabolic hormones such as testosterone,
estrogen, growth hormone, and insulin-like growth factor (Waters). All have an
anabolic (tissue-building) effect.

Another anabolic hormone under-produced with
advancing age you are undoubtedly familiar with is erythropoietin (EPO). That’s
also the name of a synthetic drug cycling has been dealing with since the early
1990s and has to do with the fall from grace of Lance Armstrong and numerous
other athletes. It’s produced normally by the body and controls red blood cell
production and their lifespan. Interestingly, it’s also associated with memory.
And, perhaps more importantly, is related to your aerobic capacity (VO2max) that
I’ve been writing about so much here. Less EPO means fewer red blood cells
which results in less oxygen being transported to the muscles and therefore a
reduced aerobic capacity. EPO production also decreases with age (Berliner).

(Some senior athletes tell me they believe there are age group competitors using synthetic EPO because they can afford it – it’s expensive – and there is seldom any testing of age group athletes. Some others are believed to be using much less expensive, over-the-counter
hormone stimulators such as dehydroepiandrosterone, also known as DHEA.
Both are banned in
competition along with other performance-enhancing drugs.)

As
with most aging conditions, we do have some degree of control, albeit quite
limited, over our hormones. You can speed up or slow down your body’s anabolic
hormone production. High intensity training (such as aerobic capacity intervals
or fartlek training) stimulates their secretion more so than low-intensity,
steady-state training (Hackney). Strength training has a similar affect
(Stokes). Both are untested in senior athletes but likely produce similar
results.

As
mentioned before, hormone secretion is especially high when you are asleep, the
key being the consistency of sleep over time rather than the duration of your
snoozing (Randler). Getting to bed at a regular time appears to be important
for natural hormone production. The type of exercise also is important. Although
preferable to no exercise at all, a steady diet of only long, slow distance
year after year while avoiding the weight room is likely to result in a steady
decline in hormonal activity.

This
latter point is why I’ve been encouraging you to train occasionally near your
aerobic capacity (my pace and heart rate zones 5b and Coggan’s power zone 5)
while doing resistance/strength training (again, see my Training Bible for details on both zones and strength training). As I’ve said
before here, there is no doubt that such training is risky. The primary risk has to do with injury, so you must be conservative when starting this sort
of training and cautious with increasing the workloads.

An
important point I’ve learned about training over thirty-some years of coaching
is that all workouts have some degree of risk associated with them. In that
regard, training is similar to investing in the stock market – the greater the
risk, the greater the potential reward. Low risk almost always means low reward
in both instances. As the risk increases so does the possibility of loss. In
the case of exercise this means injury. It also means overtraining. Even if you
are able to push yourself to an exceptionally high level of training while
avoiding injury, you are likely to become overtrained by doing too much
high-intensity training in
too little time thus reducing your hormone production (Urhausen).
Injury and overtraining are why it’s important to be conservative and cautious
with high-risk, high-intensity training.

In
my next post I’ll address optimal recovery from a training perspective and
offer suggestions on how to plan your training to include a wide range of
intensities relative to your seasonal periodization.

References

Berliner N. 2013. Anemia in the elderly. Trans Am Clin Climatol Assoc 124:230-7.

Hackney AC, Hosick KP, Myer A, et al. 2012. Testosterone responses to intensive interval versus steady-state
endurance exercise. J Endocrinol Invest
35(11):947-50.

Randler C, Ebenhöh N, Fischer A, et al. 2012. Chronotype but not sleep length is related to salivary testosterone in
young adult men. Psychoneuroendocrinology 37(10):1740-4.

Stokes KA, Gilbert KL, Andrews RC, Thompson D. 2013, Different
responses of selected hormones to thre type of exercise in young men. Eur J Appl Physiol 113(3):775-83.

Urhausen A, Gabriel HH, Kindermann W. 1998. Impaired pituitary hormonal response to exhaustive exercise in
overtrained endurance athletes. Med Sci Sports Exerc 30(3):407-14.