AGING AND STRONG
Part III: On Hormones
By Dan Wagman, Ph.D., C.S.C.S.
Thus far I reasoned through why the all-round weightlifting age adjustment formula is fundamentally unfair and lacks common sense (see Part I). I then offered scientific evidence showing that in a healthy but otherwise sedentary population the effects of aging on muscle activation are only moderate and don’t become meaningful until you reach about 70 years of age (see Part II). However, one of the issues most people consider in their aging analysis is that of hormones. The basic understanding is that as you age your body produces less hormones, whether you’re a man or a woman, and that impacts your training and ability to gain or maintain strength.
Hormones for Strength
One of the things you always hear about in older men is how their levels of testosterone and growth hormone decline. In older women, particularly postmenopausal ones, changes in hormone levels are said to cause overall physical decline. It frankly sounds like once you’re an older guy or gal, life’s over because your hormones are gone. But here’s an interesting fact about hormones, they respond quickly to the stimulus of tossing a barbell around. On the other hand, hormones are highly complex and various anabolic hormones differ in their response, not only depending on gender, but also depending on how you train. Clearly, you have to turn to research in an effort to understand the link between age, hormones, and lifting weights.
An early and interesting study looked at the acute hormonal responses in men and women after heavy weight training.(1) They looked at 30-, 50-, and 70-year old men and women after they performed training sessions in the bench press, leg press, and sit-up. They had to perform 5 sets of each exercise with the heaviest weight they could lift for 10 reps (10-rep max or 10-RM). In response to this training the researchers found that average concentrations of serum testosterone and cortisol (a hormone that tends to rise in response to stress, and lifting weights at that high an intensity certainly constitutes stress) remained unchanged in all women. In 30- and 50-year old men testosterone increased significantly while cortisol increased significantly only in 50-year old men. Regarding growth hormone, that increased in 30- and 50-year old men and women significantly. Overall, the change in growth hormone levels was significant while that of testosterone was only minor.
With all the talk about the importance of testosterone and how it decreases in men due to age, rendering them weaker, with an implication of being less-of-a-man than what they used to be, this archaic thinking doesn’t consider how testosterone levels—and growth hormone—can vary throughout the day. In the control subjects of that study the scientists looked at changes in testosterone and growth hormone levels at noon and 1400 hrs. By way of brief illustration, the 50-year olds had the smallest amounts of testosterone at noon, followed by the 70-year olds and then the 30-year olds who showed the greatest amount. At 1400 hrs. the greatest drop in testosterone was recorded by the 30-year olds followed by the 50-year old group and the least change was found in the 70-year olds. Note, however, that none of these changes, nor the different levels of testosterone in the different age categories, was significant. You could therefore argue rather successfully that if it wasn’t significant, why even discuss it?
Four years later, in 1999, researchers from Ball State University, Pennsylvania State University, the University of Jyväskylä, Southern Cross University, the University of Arkansas, and Colorado College examined the effects of heavy weight training on various anabolic hormones in younger (30) and older (62) healthy and fit men.(2) This was a very complex study where I can only share the basic findings. Suffice to say, the subjects had to adhere to a 10-week scientific training program that emphasized high intensity work at varying levels of volume in each week. At the onset of the training program the younger group displayed greater strength and muscle size than the older group. In terms of hormones, only at weeks 3 and 6 were there significantly less serum total testosterone responses for the older men compared to the younger men. Regarding free testosterone the older men displayed less of a response compared to the younger men in weeks 3, 6, and 10. For growth hormone no significant differences were found. Though this represents an interesting insight into hormones, age, and lifting weights, what happened in regard to training gains? At the conclusion of the study both groups made significant gains in strength of about 15%.
As a next step the researchers wanted to know how each age groups’ hormones would respond immediately after a very tough session of squatting consisting of 4 sets at 10-RM with 90-seconds rest between sets. They did this test before the 10-week training protocol and again thereafter. The basic findings were that older men who are healthy and fit, but not weight trainers, can be stressed with an intense weight lifting regimen and make significant gains. Also, despite the fact that the younger men increased the size of their whole thigh significantly more than the older men, the relative strength gains in the thigh were the same between groups. The researchers link this finding to differences between groups in resting and exercise-induced adaptations of hormones. Also, regardless of age, hormone level adjustments due to heavy weight lifting occur in younger and older men.
Despite the same gains in strength, in terms of total testosterone younger men displayed significantly higher responses than the older men. Therefore, the impact of the greater testosterone response in younger men might not be as impactful to strength development as previously thought. This actually makes sense, because your muscles’ ability to gain strength—and size, for that matter—is not the result of just one variable, such as testosterone. Also, in the young men cortisol responses tended to be greater than in the old men. Cortisol is a stress hormone that’s catabolic, meaning it breaks down molecules. Since the older men’s cortisol response was less than the younger mens’, the researchers suggest that this might be a physiological mechanism that allows older men to significantly gain in strength without the same testosterone response as younger men. And as it relates to growth hormone, no significant changes were noted for resting concentrations in either group throughout the training period.
Still Gaining Strength
What these studies show is that whether you’re in your 30’s, 50’s, 60’s, or 70’s you’re able to make significant strength gains. How your hormones respond might be different depending on age, but that only means that your body finds different ways to adapt to what you do in the gym. At the end of the day, if your training results in strength gains, does it really matter how your body accomplishes that? A reasonable challenge to this observation might be the amount of strength gained. Despite the fact that the first study found younger and older trainees to gain the same amount of strength, this might not be typical. Moreover, if, as I stated earlier, there’s a lot more going on in your body than just hormones to help you get stronger, what else happens when younger and older people toss dumbbells? Surely there must be a difference between a 30-year old and a 50-year old. We’ll dig deeper in Part IV.
References
- Häkkinen, K., and A. Pakarinen. Acute hormonal responses to heavy resistance exercise in men and women at different ages. International Journal of Sports Medicine 16(8):507-513, 1995.
- Kraemer, W., et al. Effects of heavy-resistance training on hormonal response patterns in younger vs. older men. Journal of Applied Physiology 87(3):982-992, 1999.
