Abdominal muscles do not need to be trained daily. Although the idea of working them every day is based on the assumption that they are composed mostly of slow-twitch muscle fibers with rapid recovery, autopsy and biopsy data show that they have a balanced distribution (approximately 50/50) of slow and fast-twitch fibers, similar to the quadriceps. Their recovery needs and training principles are therefore identical to those of other muscles in the body.

noli's read

Andrew Huberman is quite right to challenge the myth of daily abdominal training by relying on their muscle typology. The benchmark autopsy study by Johnson et al. (1973), as well as biopsy work by Häggmark and Thorstensson (1979), confirm that the rectus abdominis presents a distribution of approximately 55% type I (slow-twitch) fibers and 45% type II (fast-twitch) fibers. This composition is extremely close to that of the quadriceps (vastus lateralis muscle), invalidating the commonly held belief that the abdominals are pure endurance muscles to be worked every day. Regarding training frequency, modern research also validates this logic: a meta-analysis by Schoenfeld et al. (2016) demonstrates that at an equal volume of work, increasing training frequency beyond 2 to 3 times per week does not offer significant advantages for muscle development. Thus, the fundamental principle of recovery applies to the abdominals in the same way as it does to other major muscle groups. Huberman's explanation is therefore scientifically sound and allows one to structure a sports routine more effectively, without generating unnecessary fatigue.

the sources

1. 1Wang XQ, Zheng JJ, Yu ZW, et al. 2012