Objective This study aimed to systematically investigate whether polarized or non-polarized training leads to greater physiological and performance adaptations in cyclists. Design A systematic review and meta-analysis were conducted, focusing on interventions categorized as polarized, non-polarized, or unclear. Inclusion criteria required participants to be at least recreationally trained cyclists (VO2max = >59ml/kg/min) and interventions lasting >4 weeks. Methods A multi-level random-effects meta-analysis using restricted maximum likelihood estimation was performed. A multivariate meta-regression assessed associations between training volume, VO2max, and time-trial performance. Results Forty-one studies, comprising 81 training groups and 797 participants, were included. Training significantly improved VO2max across all groups (g=0.42, 95% confidence interval =0.31-0.53, P=0.001) and time-trial performance (g=0.39, 95% confidence interval =0.25-0.53, P=0.001), with no significant differences between training modalities (P>0.05). Longer intervention durations positively influenced VO2max (g=0.03, 95% confidence interval =0.02-0.05, P<0.001) and time-trial performance (g=0.04, 95% confidence interval =0.03-0.06, P<0.001). No associations were found between weekly or total training volume and changes in VO2max or time-trial performance. Conclusions Polarized and non-polarized training modalities yield comparable improvements in VO2max and time-trial performance in trained cyclists. Beyond achieving a necessary training volume, further increases do not appear to enhance performance. These findings encourage athletes and coaches to prioritize effective training distribution rather than fixating on total volume or a specific model Practical implications When considering training intensity distribution selection in trained cyclists, it is likely that any combination of structured training will improve VO2max, with POL offering a potential benefit over other modalities. However, while uncertain, POL may be less suitable for improving TT performance. The results of this review also emphasize that caution must be taken in relation to total training volume as increased training volume may not cause notable increases in VO2max and TT performance, especially in well-trained athletes. As such, coaches and athletes should consider a balance between volume and intensity to optimize performance. Highlights • Training interventions showed similar improvements in VO2max and time trial performance across Polarized, Non-Polarized models. • High training volumes may not guarantee better VO2max or performance, suggesting other factors are key in trained cyclists. • Athletes and coaches should prioritize training distribution over a specific model, urging further research on optimal practices.
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