ACTivating Fat OXidation Through Capsinoids

Prior evidence suggests that capsinoids ingestion may increase resting energy expenditure (EE) and fat oxidation (FATox) in humans, although whether they can modulate those parameters during exercise conditions remains poorly understood. Investigators aimed to determine the effects of dihydrocapsiate (DHC) ingestion on EE and FATox during an acute bout of aerobic exercise at FATmax intensity (the intensity that elicits maximal fat oxidation \[MFO\] during exercise) in overweight/obese men. A total of 24 sedentary overweight/obese men participated in this randomized, triple-blinded, placebo-controlled, crossover trial. On the first day, participants underwent a submaximal exercise test in a cycloergometer to determine their MFO and FATmax intensity during exercise. After 72 hours had elapsed, the participants returned in 2 further days (≥ 72 hours apart) and performed a 60 min steady-state test (SST, i.e., cycling at their FATmax, constant intensity) after ingesting either 12 mg of DHC or placebo; these conditions were randomized. Respiratory gas exchange was monitored by indirect calorimetry. Serum markers concentrations (glucose, triglycerides, and non-esterified fatty acids), skin temperature, thermal perception, heart rate and perceived fatigue were assessed as secondary outcomes.