Working out on empty stomach may be better
If you’ve been wondering whether it’s better to eat or not before a workout, researchers now have an answer. A new study has found that exercise on empty stomach is better for your health in the long term.
The study analysed effects of eating versus fasting on gene expression in adipose (fat) tissue in response to exercise. After eating, adipose tissue “is busy responding to the meal and a bout of exercise at this time will not stimulate the same (beneficial) changes in adipose tissue”, explained corresponding author of the study Dylan Thompson from University of Bath in Britain.
“We propose that feeding is likely to blunt long-term adipose tissue adaptation to regular exercise,” the researchers noted in the study, published in the American Journal of Physiology — Endocrinology and Metabolism.
The study participants were a group of overweight males who walked for 60 minutes at 60 per cent maximum oxygen consumption on an empty stomach and, on another occasion, two hours after consuming a high-calorie carbohydrate-rich breakfast.
The research team took blood samples after eating or fasting and after exercising. They also took fat tissue samples immediately before and one hour after walking.
Gene expression in the fat tissue differed significantly in the two trials. The expression of two genes, PDK4 and HSL, increased when the men fasted and exercised and decreased when they ate before exercising. The rise in PDK4 likely indicates that stored fat was used to fuel metabolism during exercise instead of carbohydrates from the recent meal.