A study by researchers at the National Institute of Nutrition (ICMR-NIN) has found that long-term athletic training significantly influences body composition, metabolism, blood physiology, dietary habits and gut microbiome, with endurance and strength athletes developing distinct physiological adaptations
The findings, published in the international journal ‘Frontiers in Nutrition’, suggest that personalised nutrition and training strategies tailored to different sports could help improve athletic performance, recovery and long-term health
The study, titled ‘Training modality-specific differences in body composition, resting metabolic rate, diet, and gut microbial signatures in elite endurance and strength athletes’, compared elite endurance athletes, elite strength athletes and physically inactive men to understand how different forms of training affect the human body
Researchers studied 80 healthy men aged between 18 and 35 years from sports academies and training centres in Hyderabad. The participants included 27 endurance athletes, 29 strength athletes and 24 sedentary individuals. All athletes had undergone at least five years of structured training, participated in a minimum of five training sessions a week, and had competed at the state or national level.
Advanced techniques, including dual-energy X-ray absorptiometry (DXA), indirect calorimetry, blood investigations, dietary assessments and gut microbiome analysis, were used to generate detailed physiological profiles
The researchers found that endurance athletes were significantly leaner, burned more fat at rest and had blood characteristics that enhanced oxygen transport, making them better suited for sustained aerobic activity. In contrast, strength athletes exhibited greater skeletal muscle mass, higher bone mineral density and elevated resting metabolic rates, reflecting the demands of resistance and power-based training.
The study also revealed notable differences in gut microbiota. Elite athletes had higher levels of bacteria associated with protein and fat metabolism compared to sedentary individuals, while inactive participants showed relatively higher levels of the Lactobacillus — a group of beneficial bacteria that reside in the gut and aid in digestion, among others. Differences were also observed between endurance and strength athletes, indicating that long-term training and dietary patterns shape the gut microbiome in a sport-specific manner.
Dr K Venkatesh, Scientist-E at ICMR-NIN and lead investigator of the study, said the findings demonstrated how regular physical activity simultaneously benefits multiple physiological systems, including body composition, metabolic health, bone health and gut microbiota, reinforcing the wide-ranging health benefits of exercise
ICMR-NIN Director Dr Bharati Kulkarni said the study underscores the importance of personalised nutrition and sport-specific training strategies. She noted that understanding these physiological adaptations could help optimise athletic performance, accelerate recovery, reduce injury risk and support long-term health among athletes
