Home > Training

Is your untrained kid a better endurance runner than you?

A study shows that aerobic fitness at the muscular level decreases significantly as children move into adulthood

A recent study shows that aerobic fitness at the muscular level decreases significantly as children move into adulthood. Disease related to physical inactivity is on the rise. Scientists Sébastien Ratel and Anthony Blazevich are curious about the physiological changes that occur with age and how knowledge of the aging process can assist in preventing disease.



The study compared 12 boys aged eight to 12 who didn’t regularly train, 12 unfit adults and and 13 nationally ranked  athletes. The study measured participants’ heart rate, oxygen levels, and levels of acidosis and lactate. All of the metics are linked to a feeling of fatigue in the muscles. The study found that children outperformed untrained adults in every test.


When compared to the nationally ranked athletes, childrens’ physical output was lower, but their recovery time was much faster. Ratel and Blazevich said, “Our findings indicate that aerobic fitness, at least at the muscle level, decreases significantly as children move into adulthood… our results might provide motivation for practitioners to maintain muscle fitness as children grow up; it seems that being a child might be healthy for us.”


Family sport, active mother and kids jogging, running in forest


The study suggests that maintaining strength is a lifelong process. If you’ve always been runner, your untrained child’s likely better at recovering than you, but probably not a better endurance athlete. That being said, encouraging your child to join you for a run could be great for their development longterm. Having a running buddy also provides quality time and extra motivation to keep training for your next goal race.

This study also serves as a reminder that as you age, prioritizing recovery is key. Taking the extra few minutes to roll, stretch and make a nutritious meal can go a very long way in injury prevention.