Ученые опровергли теорию о неизбежных компромиссах между выносливостью и долголетием на примере мышей

Whether you’re a human or a mouse, staying physically active is good for you. But one of the central ideas in evolutionary biology is that everything comes with trade-offs. If you dedicate too much energy to becoming stronger or faster, that’s energy that can’t be spent on repairing the body or living longer. But what if this idea is wrong, or at the very least incomplete? For more than three decades, researchers at the University of California, Riverside, have bred mice that run extraordinary distances. The “High Runner” mice can cover roughly three times as much ground on exercise wheels as ordinary control mice. Researchers expected that athletic extreme to carry a hidden cost: fewer offspring, shorter lives, or both. But when they finally followed 100 breeding pairs across their lifetimes, the expected penalty never clearly appeared. High performance, no downside The experiment began in the 1990s. In four High Runner lines, researchers repeatedly chose exceptionally enthusiastic runners to parent the next generation. Four other lines served as controls. So, this was selective breeding, it’s not gene editing. But over generations, the impact is huge. The runners changed in more ways than simply wanting to exercise: previous work has documented differences in body size and fat, aerobic capacity, muscles, hearts, hormones and behavior. That is exactly why a cost seemed plausible. “We did expect to find a reproductive cost for this athletic behavior,” said Theodore Garland, a distinguished professor of evolution, ecology and organismal biology who led the research team, along with doctoral student Natalie Whitehead. To look for it, the researchers took mice from generation 97 and formed 100 male-female pairs. They kept each pair together for life, recording births, pups that survived to weaning, and the deaths of both parents. Ninety-eight pairs produced at least one litter. The High Runner pairs ultimately weaned an average of about 26 pups, compared with about 29 among controls. It’s such a small gap that statistically, it’s indistinguishable from chance. The researchers also found no significant difference in average lifespan between High Runner and control mothers or fathers. Nor did animals that produced more offspring appear to pay for it by dying younger. “We also thought the runners wouldn’t live as long, but they did,” Garland told UC Riverside News. So, what gives? Where did evolution’s bill go? Evolution is supposed to keep a ledger, you can’t just cheat it. But one of the leading possibilities is that the mice could simply afford it. With unlimited food and water, they tended to eat more than the controls. All the extra calories may have served as compensation for the changes in metabolism and stress tolerance. The laboratory itself was forgiving, too. There were no predators or long searches for dinner. In harsher conditions, the daily energy costs would be higher. Future experiments combining breeding with restricted food or wheel access could reveal a trade-off that this study could not. And, of note, these results do not show that extreme exercise has the same effects in humans. What they do challenge is a simpler assumption: that improving one costly biological trait must automatically wreck another. “These are mice. They aren’t humans,” Garland said. “In people, it would take decades to conduct a comparable study, and there are all kinds of environmental and cultural factors that can influence the results.” Even so, after decades of breeding, researchers were expecting to find a significant cost for the endurance of these mice. The fact that the bill never arrived suggests there’s something else at play. Whether or not something similar would happen in humans remains to be confirmed. Journal Reference: Natalie N. Whitehead et al, Selective Breeding for Voluntary Wheel-Running Behavior in Mice is not Associated with Reduced Lifetime Reproductive Success or Lifespan Under Long-Term Paired Breeding Conditions, Behavior Genetics (2026). DOI: 10.1007/s10519-026-10277-x