Since the dawn of the fitness industry and fad diets, this question has been raised: which is better for fat loss — eating or not eating before a morning workout?
Some say fuel before a workout boosts blood sugars, giving the body energy to increase the intensity and length of a workout while fighting off fatigue and dizziness. The eat-after proponents say that you burn more fat if you fast before exercise.
According to CNN Health, a recent UK study supports the latter point of view. The study included 30 obese or overweight men who were followed for six weeks. Those who exercised before breakfast burned twice the fat as the men who ate breakfast before they worked out.
In one aspect, working out without fuel allows the body to better use what has been stored rather than what is currently in the bloodstream from the meal prior to exercise. Fasting before exercising forces the body to turn to stored carbohydrates, and after this initial supply has been used, to quickly shift into burning fat cells.
While study participants in the eat-after group didn’t lose more weight than the eat-before group during the six weeks of the study, skipping the meal before exercise did have “profound and positive” effects on the health of the eat-after group, researchers say (CNN Health, October 2019).
Not only is an individual burning more fat as fuel, when carbs are stored away as glycogen to replenish a worked muscle or tissue, the body’s response to insulin is also changing. Fasting before exercise made the men’s muscles more responsive to insulin, which controls high blood sugar levels, helping to ward against diabetes and heart disease.
“The group who exercised before breakfast increased their ability to respond to insulin, which is all the more remarkable given that both exercise groups lost a similar amount of weight and both gained a similar amount of fitness ... the only difference was the timing of the food intake,” stated researcher Javier Gonzalez, an associate professor in the Department for Health at the University of Bath.
If burning more body fat is the main goal, engaging in steady-state or interval cardio training in a fasted state will yield the best results for fat loss.
If you are a power athlete or an individual aiming to lift weights and strength train at a higher intensity, having the primary fuel source — carbohydrates — present will be necessary to perform at optimal levels to achieve the desired outcome in those areas that aren’t directly related to weight loss.
At the end of the day, make fitness goals that work for you.
— Eric Bishop is fitness supervisor at Edward-Elmhurst Health & Fitness in Woodridge.
