Maintain a load intensity between 60% and 80% of your 1RM during the learning phase of a movement to avoid technical failure.

noli's read

This advice is based on the principle of motor specificity: to learn a complex movement, it must be practiced under conditions close to actual performance without accumulating excessive fatigue that would degrade form. Research in sports science, particularly work on the period of motor acquisition, confirms that training with a repetition buffer (moderate RPE) allows for better stabilization of neurological patterns than muscular failure. Meta-analyses on hypertrophy and strength (Schoenfeld et al.) support that this load range is optimal for qualitative work volume. The idea here is to favor perfect repetition to create solid muscle memory. There is nothing exaggerated here; it is a prudent recommendation proven by practice in powerlifting. No evidence contradicts the idea that too much fatigue hinders initial technical learning.

the sources

1. 1strongerbyscience.com