A study conducted at the University of Oklahoma (Norman) had 28 subjects take either a supplement containing both caffeine and capsaicin or a placebo before engaging in low-intensity exercise. Researchers who measured how many calories the subjects burned both during the exercise and at rest afterward found those who had taekn the caffeine-capsaicin supplement burned more calories during exercise, as we would expect.
When they had the taken the supplement, subjects also burned more calories at rest after exercising than when they took the placebo. If you are looking to drop a bit of extra fat, make taking caffeine and capsaicin--together- part of your preworkout routine.
Ryan, E.D., et al. "Acute Effects of a Thermogenic Nutritional Supplement on Energy Expenditure and Cardiovascular Function at Rest, During Low-Intensity Exercise, and Recovery From Exercise."