Benefits of Elite-Level Fitness May be Lost in Old Age
I’ve written enough about the topic of cardiovascular aging and how exercise is beneficial in preventing it. There is little argument that exercise is good when you’re young, and perhaps even better as you age — helping to prevent the myriad of age-related changes to blood vessel structure and function that are major risk factors for cardiovascular disease (CVD) risk.
Master’s athletes and even older adults who engage in regular, consistent physical activity show significantly better cardiovascular function compared to age-matched peers who engage in little to no physical activity. In fact, if you exercise as you age, you can maintain similar levels of blood vessel health to that of younger adults.
A new study proposes a totally different and quite novel hypothesis related to exercise and aging. Rather than study the well-known benefits of exercise with age, the question was posed:
“Do older adults who were previously engaged in high-level activity and training demonstrate superior cardiovascular aging compared to non-athlete older adults?”
That is — if you were once an elite athlete, but then stopped training, do you maintain some of the benefits decades later?
The study, published in the Journal of the American Heart Association, tested the hypothesis that age-dependent changes in endothelial function and arterial stiffness (highly covered topics on this blog) — two strong predictors of CVD— would be delayed in former endurance- and sprint-trained athletes compared to age-matched controls (untrained).
Study population
A total of 94 men participated in this study — 47 old and 47 young men. Within the old and young groups, they were further stratified into three different categories based on activity — endurance-trained, sprint-trained, or untrained (the control group).
The older endurance- and sprint trained athletes, in contrast to the young athletes, were no longer actively engaged in training. In fact, they’d been “retired” for an average of 27 years and now reported engaging in low-level activity of around 120 minutes per week.
What’s super cool about this study population is that they represent the cream of the crop — the former and current athletes had all competed in their respective events at the national and international level (i.e. country or world championships and the Olympics). This means they didn’t just study recreational-level athletes, but people (men) who probably represent(ed) the peak of human physiology, especially in terms of cardiovascular performance.
Study measures
This study included a ton of measures related to cardiovascular and metabolic health — so I’ll only cover them briefly.
To assess cardiovascular health and aging, flow-mediated dilation (FMD) of the brachial artery, pulse-wave velocity, and augmentation index were measured. FMD is a measure of how well your blood vessel responds to an increase in blood flow (more relaxation = better endothelial function) and pulse-wave velocity and augmentation index measure the stiffness of your arteries (aging is typically associated with an increase in arterial stiffness). Central systolic, diastolic, and pulse pressure were also measured.
The study also assessed carotid intima-media thickness — the thickness of the wall of the carotid artery. Greater wall thickness is a sign of early atherosclerosis and positively correlates to cardiovascular disease risk.
Blood was analyzed for several different outcomes: inflammatory cytokines including TNF-alpha, interlekin-6 (IL-6), C-reactive protein (CRP), blood glucose and lipids (i.e. cholesterol), and other metabolites related to vascular function.
To assess how aging and exercise training influence all of these variables, comparisons were made among the young and old men, as well as within the subgroups (meaning they compared old and young endurance trained, sprint trained, and untrained athletes to each other).
Effect of Aging on Study Outcomes
Before discussing how training influenced the outcomes of this study, we’ll touch upon the independent effect of aging. Not surprisingly, the older group of men demonstrated significantly higher arterial stiffness, blood pressure, and carotid artery wall thickness compared to younger men. They also had reduced endothelial function (lower FMD), higher levels of blood glucose and lipids, and greater levels of low-grade inflammatory markers.
These data pretty much line up with any other study on aging and cardiovascular/metabolic outcomes, and don’t add much novel data to the discussion on mechanisms of aging.
Effect of Previous Training on Cardiovascular Aging
Now on to the interesting part — and maybe the most surprising (or not) result from this study. How does previous training impact the trajectory of cardiovascular aging.
It turns out, when training was introduced as a variable, nothing changed.
That’s right, in the older athletes, previous elite-level training had no significant influence on age-related changes in arterial stiffness, endothelial function, blood parameters, or systemic inflammation. The older athletes had comparable levels of all outcomes to those of the untrained age-matched men.
Let’s Discuss
The major finding of this study was that, despite once being engaged in elite-level athletics, older athletes weren’t any more protected against the impairments in cardiovascular function that occur as a result of normal aging. This suggests that any benefits gained from training at a young age aren’t “maintained” into older age.
Olympic level training, while likely resulting in supreme fitness at a young age, inevitably withers with time.
While this doesn’t line up with the original study hypothesis, I can’t say I’m too surprised. Exercise is good, and the benefits can last a decent amount of time. However, we know from “detraining” studies that just 4–6 weeks of inactivity can erase most if not all of the benefits gained from an endurance training program.
In this study, it wasn’t just 6 weeks of inactivity — it was 27 years! These men weren’t “sedentary” for all of that time, but based on the study data, they barely engaged in 2 hours of exercise per week — not even meeting the baseline physical activity recommendations. Where before they reported engaging in nearly 1100 minutes of activity (in their “prime”), their current activity represent less than 1/5 of that.
One of the major reasons for that lack of maintained benefits, as the authors discuss, is probably the increase in body fat percent and BMI that also correlated with increasing age. In fact, a higher BMI and body fat % correlated with arterial stiffness, blood pressure, arterial wall thickness, and inflammatory cytokines in the entire study population.
It is well known that adipose tissues can lead to chronic low-grade inflammation, and inflammation is linked to endothelial dysfunction and arterial stiffness. Along with oxidative stress, inflammation is one of the more well-evidenced causes of aging. To put it crudely — getting “fatter” with age is probably one of the primary causes (in this study, at least) of cardiovascular aging.
Who knows how these results would be different if the former athletes had maintained a similar body composition, even in the absence of continuing to train. I propose that they might still experience a decline in many of the study outcomes simply due to their “inactivity.”
The moral of the story; we can’t “precondition” ourselves when we are younger and expect that the benefits will carry over into old age. While good habits and genetic programming are surely influenced by early-life factors, it seems like we need to maintain a robust (or at least adequate) physical activity regimen well into old age, so long as we wish to stave off the seemingly inevitable effects of aging on our cardiovascular system.
References
Seals DR, Nagy EE, Moreau KL. Aerobic exercise training and vascular function with ageing in healthy men and women. J Physiol (Lond). 2019
Majerczak J, Grandys M, Frołow M, et al. Age-Dependent Impairment in Endothelial Function and Arterial Stiffness in Former High Class Male Athletes Is No Different to That in Men With No History of Physical Training. J Am Heart Assoc. 2019;8(18):e012670.
