Boys, including those of a healthy weight, have become less fit over the past 20 years, according to new research by Malaga University in Spain.
During the study researchers tested the aerobic fitness of normal and obese 11-year-old boys in 1996 and again in 2016, to compare aerobic fitness over time. The boys wore a heart rate monitor during a shuttle run test (bleep test), requiring them to run 20 metres between two points until they could no longer do it before the bleep sounded. Pulse beats per minute were recorded at the end of the test and every minute during recovery.
Results showed that healthy weight boys in 2016 were markedly less fit than their predecessors in 1996, running an average of 5.1 shuttles in 1996 and 4.8 in 2016. In contrast, over 20 years significant differences in the shuttle run test were not seen in obese boys (4.2 vs 4.1).
Importantly however, both normal and obese boys showed much lower cardiac efficacy and worse heart rate recovery at the end of the test and throughout recovery in 2016 compared to 1996. For example, in 2016 normal boys’ average heart rate at the end of the test fell from 181 bpm to 147 bpm after 1 minute to 136 bmp after 2 minutes; whereas in 1996 average heart rate was 198 bmp at the end of the beep test, and fell to 155 bmp after 1 minute and to 133 bmp after 2 minutes.
The researchers conclude by calling for more initiatives to increase fitness levels in children: ‘Our results suggest that measuring BMI alone may not be enough to monitor children’s future health and reinforce the need for promoting physical activity, especially aerobic fitness, to improve the capacity of the heart and lungs and better post-exercise recovery.’
‘We know that most children do not take part in enough physical activity, compared to current WHO recommendations of at least 60 minutes of moderate-to-vigorous exercise every day such as swimming, football, or dancing.’