Fasted vs. Fed Steady-State Cardio

Fasted vs. Fed Steady-State Cardio

A popular question people have is whether they should perform steady-state cardio fasted or fed. While opinions vary, a recent study published in the Journal of the International Society of Sports last week provides a research-backed answer.

In the study, 20 healthy young women were each given an individualized, calorie-restricted meal plan. The women were then divided into two groups. Both groups performed an hour of cardio, which includes a 5 minute warm-up and cool down at 50% maximal heart rate (MHR) and 50 minutes of steady-state cardio at 70% (MHR). They did this 3 times a week in the morning for 4 weeks. The difference between the two groups was that one group performed cardio on an empty stomach followed by a meal-replacement shake, while the other group consumed the shake before they did the cardio.

The results after the 4 weeks showed that both groups lost weight and fat mass. However, there was no significant difference between groups. Nor was there a significant difference between fat-free mass (e.g. muscle) between groups.

In summary, the researchers conclude that changes in body composition due to the combination of aerobic exercise and a calorie-reduced diet are similar regardless of whether the person is fasted or fed.