Effects of Intermittent Running on Metabolic Health

The same procedure will be repeated for all trials: Participants will be asked to perform 3 trials in a randomized-crossover design [moderate-intensity continuous running (MICE: 60% V̇O2max), 5-minute interval running (5MIN; 50% and 70% V̇O2max), 2-minute interval running (2MIN; 50% and 70% V̇O2max)]. All trials will be separated by at least 4 days wash-out and less than 14 days between trials to ensure complete rest.

Sensors for measuring muscle oxygen (10 cm proximal to the mid-patella, and 2 cm lateral) will be placed on the rectus femoris muscle and 15 min resting metabolic rate was measured. After baseline measurements, participants warm-up for 3 minutes with fixed walking intensity (i.e., 5 km/h) followed by 40 minutes running. Immediately after the running, participants return to a seated position for 30 minutes post-exercise measurements (EPOC).

During the EPOC and resting metabolic rate (RMR) measurement participants will sit in a comfortable position and need to limit fidgeting, thus allowed only to watch TV or videos on their phone. Participants will be wheeled to the bathroom if needed.

Inclusion criteria

• Healthy recreationally active men
• BMI between 18.5-27 kg/m2
• Aged between 20 to 45 years
• Regular exercise (3 times per week and longer than 3 months) with cardio exercise longer than 30 minutes at least once a week
• Weight stable for more than 3 months (no change in weight +/- 3%)
• Non-shift workers and sleep at least 6.5-9 hours for the past 3 months
• Non-smoker

Exclusion criteria

• having any cardiovascular, metabolic or pulmonary disease (angina pectoris or uncontrolled arrhythmias)
• suffering from infectious contagious diseases,
• using medications that could affect metabolic responses (including anti-inflammatory medications)
• smoking
• heavy alcohol intake (more than 4 drinks on any day or more than 14 drinks a week).
• undergoing special diets (e.g., intermittent fasting and/or ketogenic diets)