The caffeine and bicarb stack adds nothing over caffeine alone
Pooled trials show the popular pre-race combination modestly beats placebo, lifting mean power by 8.43 W and trimming time trials by an estimated 1.6%, though those gains wobbled when single studies were removed. Against caffeine or bicarbonate taken on their own, the stack showed no extra benefit.
For you: If you already use caffeine before hard sessions, this is no reason to add sodium bicarbonate on top; the combination has not been shown to beat either ingredient alone.
What it shows: Take the stacking claim lightly: results pooled from 13 small trials where each athlete tried every condition, and the apparent gains over placebo disappeared when single studies were removed. Nothing here shows the combination beats either supplement on its own.Meta-analysis · Nutrients