During weightlifting, the biceps muscle often shows higher electrical activity than the triceps, even when the biceps is not the primary mover, suggesting that the specific exercise being performed...

We analyzed two assertions about muscle activation during resistance exercises, and both support the idea that the biceps often show higher electrical activity than the triceps, even when it’s not the main muscle moving the weight [1][2]. This suggests that the type of exercise being done may play a bigger role in how active a muscle becomes than whether it’s primarily pushing or pulling. In exercises like concentration curls and kickbacks, the biceps consistently recorded higher levels of electrical activity compared to the triceps, regardless of whether the biceps was the main mover or acting as a stabilizer or opposing muscle [2]. Similarly, across a range of weightlifting movements, the biceps tended to show more activation than the triceps, even in tasks where the triceps should logically be doing more work [1]. These findings point to a pattern where the specific movement pattern, not just the muscle’s role, influences how much the muscle is engaged. We did not find any studies that contradicted these observations. However, the evidence we’ve reviewed is limited to just two assertions, each supported by 28 data points, and does not cover all possible exercises or populations. It’s possible that in other movements — such as heavy pressing or overhead extensions — the triceps might show higher activation, but that wasn’t included in what we’ve reviewed so far. What this means for someone lifting weights: if you’re doing exercises where the biceps are involved — even as a secondary muscle — it may still be working harder than you expect. This doesn’t mean the triceps is underactive, but rather that the biceps might be more responsive in certain movements. Pay attention to how your arms feel during different exercises, and don’t assume the muscle you think is doing the work is the one working the most.