For young women who want to improve their aerobic fitness, weight loss may not matter, researchers found.
These data were presented at the virtual American Heart Association’s Basic Cardiovascular Sciences Scientific Sessions.
“First, the relationship between weight and aerobic performance may be different in younger athletes and in particular younger athletic women,” J. Sawalla Guseh, MD, an instructor in medicine at Harvard Medical School and a cardiovascular physician-scientist at Massachusetts General Hospital, told Healio. “Second, operating at the extremes of BMI may prove aerobically counterproductive for young women and, thus, may harm aerobic performance. Finally, these data remind us that a low BMI is not a prerequisite for high aerobic fitness.”
Researchers analyzed data from 2,224 participants (805 women) aged 17 to 91 years who were referred to the CV performance program at Massachusetts General Hospital between 2011 and 2019. Cardiorespiratory fitness was examined and expressed as the percentage of predicted peak VO2.
“It was important to study the relationship between BMI and cardiorespiratory fitness because there is a common preoccupation among athletes in endurance sports that weight loss and, in particular, achieving a low BMI might improve their competitive performance,” Guseh said in an interview. “However, data on the topic has been mixed based on small numbers, and focused on men.”
Participants had a mean peak VO2 of 34.3 mL/kg/min and a mean predicted VO2 of 105%. There was an inverse association between BMI and cardiorespiratory fitness in men (beta = 0.043; P = 3.3 x 10-33) and women (beta = 0.051; P = 1.6 x 10–13) aged at least 30 years. This was also observed in men younger than 30 years (beta = 0.025; P = .005).
Linear associations were not observed in women aged 17 to 29 years (beta = 0.0078; P = .38).
Using a quadratic model, researchers found a direct relationship at a lower BMI in addition to an inverse relationship with a higher BMI.