Abstract: So far aging studies have concentrated on endurance athletes. Master sprint-trained athletes were not the main focus of attention. We propose the novel hypothesis that the sprint model of lifelong physical training which involves high-intensity exercise is at least as beneficial as moderate-intensity endurance exercise for successful aging. This article provides evidence that lifelong sprint-oriented training is equally beneficial for successful aging as endurance training is.
Alex’s Notes: Have you ever wondered what effects lifelong training modalities have? Sprint-trained athletes are those who compete with short maximum-intensity exercise such as track sprinters and high/long jumpers. Conversely, endurance athletes are those who do long-distance events at a low intensity, such as marathons. The current review simply aims to attempt to compare health and aging related benefits of sprint and endurance training. It should be noted that this review relies heavily on the authors previously published work, and the athletes analyzed in these articles were typically master athletes. The authors mention that they recruited “the best of the best” athletes that commonly placed within the top ten in European or world championships in their events.
According to their previous research, sprinters have a lower average VO2max compared to endurance athletes, confirming previous studies. However, the rate of decline in VO2max was significantly less (by 32%) than the endurance runners, suggesting that the training benefits are more resilient in sprinters. Moreover, the endurance runners saw acceleration in decline after age 50, but this was not the case in sprinters. Overall this resulted in an equivalent VO2max in both athletes around age 80. The same exact patterns were observed for submaximal aerobic capacity as well.
Using the Homeostatic Model Assessment of insulin sensitivity, the researchers found that insulin sensitivity and pancreatic β-cell function were not associated with age in either athletic group, but declines were seen in the untrained controls. In other words, sprinters and endurance athletes demonstrate stable and efficient glucose metabolism across their entire life (20-90 years). That said, VO2max was associated with significantly lower fasting glucose and insulin as well as better insulin sensitivity for everyone, suggesting that endurance athletes fair better. Moreover, the lipid profile was more advantageous for endurance athletes than sprinters, although older athletes of both classes were significantly better than younger untrained controls.
Older sprint and endurance athletes have similar levels of low body fat, but sprinters have significantly more lean body mass, suggesting more muscle mass. They also have greater bone mineral density in the legs, hip, lumbar spine, and trunk. Interestingly, results for endurance athletes are often ambiguous, indicating somewhat greater but sometimes similar bone mineral density compared to untrained controls. The authors propose two explanations: (1) greater skeletal size allows exertion of larger muscle forces supporting engagement in sprint disciplines, or (2) forces exerted during sprinting induce skeletal adaptation and enhance bone mineral density. Sprinters also demonstrate significantly better neuromuscular function, while endurance athletes are no better than controls.
But what good is training if you can’t stick with it. A purely endurance-based exertion is perceived as being more strenuous than sprinting. On the other hand, less-fit individuals may perceive the single bout of high-intensity exercise as stressful. Interestingly, master sprinters begin training much earlier, usually entering competition between the ages of 20-30 years, while endurance athletes start at the around age 40 or later. This does suggest that endurance activities are simpler and easier to train for.
It is worth considering what extent physical training itself has on the beneficial effects of athletics. We must remember that physical fitness, activity, and training responsiveness have a genetic component that may modify the risk for many diseases. This could also lead to self-selection, whereby the athletes who are “gifted” because of genetics are the ones that participate and thrive. Perhaps it is not the training per se, at least not entirely, but rather the combination of genetic and environmental (diet, sleep, social, psychological) factors that influence health.
Regardless, the endurance model of training is the mainstream preferred method, and not without reason. The benefits of endurance exercise have been demonstrated repeatedly, but rarely has this model been compared to others. Long-term spring oriented training promotes more effectively bone mineral density, muscle mass, neuromuscular function, and possibly training adherence, whereas endurance training is more effective in promoting a high aerobic capacity, cardiovascular function, and glucose and lipid metabolism. Thus, it really does seem prudent to do some of both.