Background: In the present investigation we compared blood epinephrine (EPI), norepinephrine (NE), free fatty acids (FFA) and glycerol concentrations in response to a capsaicinoid supplement or placebo in healthy adults before and after acute exercise.
Methods: Twenty subjects ingested a placebo or supplement (Capsimax, OmniActive Health Technologies; 2 mg capsaicinoids in a microencapsulated matrix) with one week separating conditions. Fasting blood samples were collected during each visit; 30 minutes following a rest period and before placebo or supplement intake (Pre); 2 hours post intake (2 hr); one minute following the cessation of 30 minutes of exercise performed at 65% of maximal heart rate reserve (2.5 hr); 90 minutes following the cessation of exercise (4 hr). Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure were recorded at all times.
Results: A time effect was noted for HR, SBP, and DBP (p < 0.05), with HR and SBP higher at 2.5 hr compared to Pre (due to exercise) and DBP lower at 2.5 hr compared to Pre. No interaction or condition effects were noted for EPI, NE, FFA, or glycerol (p > 0.05). However, a time effect was noted for all variables (p < 0.0001), with values higher than Pre at 2.5 hr for EPI and glycerol, at 2 hr and 2.5 hours for FFA, and at 2 hr, 2.5 hr, and 4 hr for NE (p < 0.05). In terms of percent change from Pre, glycerol was higher with Capsimax than for placebo at 4 hr (p = 0.011) and FFA was higher with Capsimax than for placebo at 2 hr (p = 0.025) and at 2.5 hr (p = 0.015).
Conclusion: Ingestion of low dose (2 mg) Capsimax was associated with an increase in blood FFA and glycerol at selected times post ingestion, as compared to placebo. However, Capsimax had no differing effect on EPI or NE compared to placebo. Lastly, no difference was noted in HR, SBP, or DBP between placebo and Capsimax.