Strenuous cycling over a week significantly reduces visceral fat and improves metabolism.
Recent research, published in the American Journal of Physiology-Endocrinology and Metabolism, examined how a week of intense cycling could lead to a reduction in visceral fat, ectopic fat, and overall fitness, finding that committing to this routine over the course of seven days led to abdominal fat loss. Although the participants increased their energy intake to keep pace with their high energy expenditure, they still experienced notable reductions in visceral fat (fat in the abdomen area) and improvements in cardiometabolic markers, all while maintaining their fitness levels.
The study involved 13 healthy male cyclists from Québec City, aged between 50 and 66. These men, who were already seasoned cyclists averaging around 5,490 kilometers per year, cycled an intense 1,144 kilometers over seven days. Their body composition, fat distribution, and cardiometabolic health were assessed before and after the weeklong event using magnetic resonance imaging (MRI) and bioimpedance analysis.
Despite experiencing minimal weight loss over the course of a week (just a 1% reduction on average), the participants demonstrated a 14.6% decrease in visceral adiposity. This is significant because visceral fat, which surrounds internal organs, is more strongly linked to health issues such as heart disease and metabolic disorders compared to subcutaneous fat, which lies beneath the skin. The participants also showed reductions in waist circumference, a common marker for health risks related to fat accumulation around the abdomen.
Throughout the week of cycling, the participants consumed meals that were specifically designed to match their energy output, and their energy intake was tracked daily. The data revealed that their calorie consumption was higher on longer cycling days (208 kilometers) compared to shorter ones (104 kilometers). However, despite the carefully controlled diet, the cyclists maintained an overall energy deficit of 6,867 calories over the course of the week. This energy imbalance, despite the higher food intake, contributed to the reduction in visceral fat and improvements in overall metabolism.
The team also found that the cyclists experienced improvements in their lipid profiles, with total cholesterol dropping by 21.5% and non-high-density lipoprotein cholesterol by 34.6%. These changes suggest that extreme cycling positively impacted cardiovascular health, even though the cyclists’ weight did not significantly decrease. Additionally, the cyclists displayed an increase in the adiponectin/leptin ratio, indicating improved function of adipose (fat) tissue.
The study’s authors noted that this is one of the first studies to document the varying changes in subcutaneous, visceral, and ectopic fat following an extreme endurance exercise protocol. While reductions in visceral fat were clear, the researchers found no significant changes in subcutaneous fat or fat accumulation in the heart or liver. The study’s focus on endurance cycling provides a unique insight into how extreme physical activity can alter fat distribution and metabolic health without leading to vast changes in weight.
The findings highlight the importance of focusing on body composition changes rather than weight alone when evaluating the benefits of exercise, particularly for long-term health outcomes. Promoting physical activity, rather than merely focusing on calorie restriction, may be a more effective strategy for preventing obesity and heart disease.
Overall, the research reinforces the notion that the human body thrives on physical activity. Further research involving a more diverse population is needed, including women and individuals with varying fitness levels, to fully understand the broader implications of these findings.
