The other, though, is complicated and not obvious, but mechanistically interesting.

另一个分子虽然复杂，又不明显，但在机制上很有趣。

Mechanistically, this difference might be explained by caffeine's connection to improving motor unit recruitment, or the ability of your brain and muscles to communicate and contract your muscle fibers.

从机制上讲，这种差异可能是因为咖啡因与提高运动单位募集有关，或者是与大脑和肌肉交流和收缩肌肉纤维的能力有关。