However, a more recent study by Lim et al.  reported that 10 g of red peppers (containing capsaicin) taken BVD-523 before exercise Staurosporine manufacturer increased carbohydrate oxidation, which the authors suggested could limit endurance performance by exhausting glycogen stores. These findings  may, in part, explain the results of the present study, which found no differences in cycling endurance time between the TPB and PL trials. Additional ingredients in the TPB supplement included black pepper extract (i.e., bioperine), which is purported
to have same metabolic effects as capsaicin. It is possible that the combined effects of caffeine, capsaicin, bioperine, and niacin may be most evident at higher doses during longer duration, lower intensity endurance exercises – particularly in trained individuals [8, 24]. Future research is necessary to examine the potential dose-response mechanisms
for the TPB supplement ingredients during a range of exercise intensities. An interesting outcome was that the BP and LP 1-RM values at baseline were less than the 1-RM values recorded for the TPB and PL trials (Table 1). These results suggested that the participants experienced a learning effect from the baseline trial to the TPB or PL trials . Hyllegard, Mood, and Morrow  recommend using a baseline familiarization or “”learning”" trial to overcome the confounding influences of the learning check details effect. Therefore, the inclusion of the baseline measurement in the present study may have been helpful to avoid the learning effect for the 1-RM scores. In addition, the average TTE was approximately 5% greater for the TPB trial than the PL trial (Table 1). Perhaps the relatively high variability in TTE scores cAMP (coefficient of variation = 37.5%) may have prevented this difference from reaching statistical significance. Conclusion Overall, the results of the present
study indicated that the TPB supplement containing 200 mg of caffeine, 33.34 mg of capsicum extract, 20 mg of niacin, and 5 mg of bioperine did not improve the 1-RM scores for the BP or LP exercises, TTE at 80% VO2 PEAK, or RPE during the TTE test. Even though the TTE for the TPB supplement was 5% greater than the PL trial (Table 1), this finding did not reach statistical significance (p = 0.403). The lack of observed ergogenic effects may have been related to a combination of factors including: (a) the dose of caffeine was too low, (b) the exercise intensity was too high for a metabolic-enhancing supplement like TPB, (c) the participants were not well-trained, and/or (d) the caffeine and capsaicin may have increased carbohydrate oxidation (as opposed to the glycogen sparing effect ), which may have counteracted any potential ergogenic effects of the TPB.