Time-restricted eating for performance and health in recreational runners Original paper

In this randomized crossover study, time-restricted eating did not have an effect on aerobic capacity, body composition, or metabolic health in recreational male runners.

The effects of intermittent fasting (TRE) on aerobic capacity, body composition, and metabolic health.

15 men (ages 18–30) in Lisbon, Portugal who had engaged in endurance running at least 3 times per week over the previous 3 years.

The participants’ weekly running volume varied from 15 to 30 km per week.

In this randomized crossover study, the participants in the intervention group consumed 2–3 meals within an 8-hour eating window daily for 4 weeks. Within the remaining 16 hours of each day, only water, tea, and coffee without any caloric additives were permitted. The participants in the control group were permitted to eat at any time throughout the day with no restrictions. After a 2-week washout period, all participants switched to the other treatment group for an additional 4 weeks.

The participants in both groups followed identical training regimens, which included 3 runs per week on nonconsecutive days.

A series of measurements were collected immediately before and after each of the 4-week periods to evaluate aerobic capacity, body composition, and metabolic health.

Aerobic capacity was measured by graded exercise tests performed on a motorized treadmill. Oxygen uptake was recorded during the test with a portable mixing chamber, and heart rate was recorded using a heart rate monitor. Body composition was measured by DXA scans. Metabolic health was measured by the levels of total cholesterol, HDL, LDL, triglycerides, and fasting glucose in the blood, as well as blood pressure readings.

There were no differences in measures of aerobic capacity, body composition, or metabolic health between the TRE group and control group.