Children's Muscles Recover Faster from Exercise than Endurance Athletes, New Research Suggests

Children's muscles recover from high-intensity exercise faster than endurance athletes, a new study has revealed.

By building on previous research showing children have better endurance than relatively unfit adults when performing physical tasks, the team investigated if children tire as quickly as athletes when cycling.

The researchers asked three groups—12 boys aged between eight and 12 who didn't regularly train, 12 unfit adults and 13 national competition-level athletes—to perform cycling tests. To test how quickly they recovered from exercise, researchers monitored participants' heart rate, oxygen levels, and levels of acidosis and lactate - which are linked to the sensation of tiredness in muscles. They used this information to determine whether the children used their aerobic or anaerobic metabolisms when their bodies were exerted during physical exercise. The children outperformed the untrained adults in every test.

In a joint statement seen by Newsweek, co-authors Sébastien Ratel—associate professor in Exercise Physiology at the Université Clermont Auvergne, France— and Anthony Blazevich — Professor in Biomechanics at Edith Cowan University, Australia — highlighted that children tire easier than adults during physical activity. That is because their cardiovascular systems are less capable, and are more likely to make inefficient movements as their bodies are smaller.

Ratel told Newsweek: "This new study is significant because we found that the children used more of their aerobic metabolism and were therefore less tired during the high-intensity physical activities than adults. Children also recovered very quickly, even faster than the well-trained adult endurance athletes, as demonstrated by their faster heart rate recovery and ability to better remove lactate, a metabolic byproduct contributing to muscle fatigue."

The authors hope their findings could help scientists better understand how the human body changes with age, and the part this plays in the risk of diseases like diabetes. The latest figures published in 2017 show that an estimated 30.3 million people in the U.S. have the chronic condition.

"With the rise in diseases related to physical inactivity, it is helpful to understand the physiological changes with growth that might contribute to the risk of disease," Ratel said.

He added: "Our research indicates that aerobic fitness, at least at the muscle level, decreases significantly as children move into adulthood, which is around the time increases in diseases such as diabetes occur. It will be interesting in future research to determine whether the muscular changes we have observed are directly related to disease risk. At least, 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."

Paul Hough, sport and exercise scientist at St Mary's University, London, and author of Advanced Personal Training (who wasnt involved in the research) told Newwsweek said that while the findings are interesting there could be a misconception that children are fitter than adults and athletes. "We have to bear in mind the adults and athletes are generating higher absolute power outputs," he argued.

"It is also difficult to link the changes in recovery profile to the risk of developing chronic diseases, as there are numerous factors that contribute to diseases such as diabetes and heart disease. For example, genetics, nutrition, daily physical activity levels and much more."

He added: "I would suggest that diet and daily physical activity play a more important role in chronic diseases than changes in fatigue recovery profile."