Polarized training is superior to other training intensity distribution models for the improvement of VO2peak. There was no evidence of polarized training superiority for any of the remaining endurance performance surrogates investigated.

Polarized training superiority was mostly evident for interventions lasting less than 12 weeks. When exercise interventions were longer than 12 weeks, VO2peak was shown to increase similarly in those using POL or other training intensity distribution models.

Baseline endurance performance level was shown to influence the effect of polarized training on VO2peak improvement in highly trained/national level athletes.