4.5. Directions for Future Research
Given the relatively ad libitum nature of the intervention which required no conscious efforts to restrict energy intake or increase physical activity, it is worth considering that these gradual changes may amount to clinically meaningful effects over a longer study duration. Longer-term investigations in active and trained populations—such as those lasting 6–8 weeks or longer—are therefore needed. The understanding of the chronic effects of thermogenic supplementation would further benefit from the inclusion of outcomes similar to those in the current investigation, including fasted REE and subjective variables, such as mood, hunger, and sleep quality.Recreationally active individuals and athletes commonly supplement with protein and/or thermogenic products such as caffeinated multi-ingredient pre-workout supplements and energy drinks [