The community suggests that there is an incompatibility between heavy loading and repetitive spinal flexion movements (such as traditional sit-ups or certain yoga postures), as athletic performance would instead require prioritizing trunk rigidity.

noli's read

Stuart McGill is a major academic authority in spinal biomechanics, and his work on 'cumulative load' is widely recognized. Science does support the fact that repeated flexion under load can increase the risk of disc injury in certain individuals, validating the idea of limiting these movements during intensive programs (observational studies and biomechanical models by McGill). However, the idea that flexion must be completely proscribed is an often exaggerated interpretation; research shows that the spine possesses an adaptive capacity and that movement variability is essential for long-term joint health (reviews on tissue tolerance). The correlation between lordosis and power in sprinters is a documented anatomical fact, but extrapolating it as a universal rule for all athletes remains a simplification. There is no robust evidence that total rigidity is superior to a mobile and resilient spine for the general population. The forum converges toward a cautious and specialized application of McGill’s principles rather than a total rejection of movement.

the sources

1. 1r/AdvancedFitness