Polarized Versus High-Intensity Multimodal Training in Recreational Runners

This study longitudinally compared changes in running performance (5-km time trial) and fitness (maximal oxygen uptake [VO2max] and body composition [BC]) between polarized training and CrossFit Endurance (CFE) in recreational runners.

Participants (N = 21) completed 12 wk of CFE or polarized endurance training (POL). Both groups trained 5 d·wk-1. POL ran 5 d·wk-1, whereas CFE ran 3 d·wk-1 and performed CrossFit 3 d·wk-1 (run + CrossFit 1 d·wk-1). Intensity was classified as low, moderate, or high (zone 1, 2, or 3) according to ventilatory thresholds. POL was prescribed greater volume (295 [67] min·wk-1), distributed as 85%/5%/10% in Z1/Z2/Z3. CFE emphasized a lower volume (110 [18] min·wk-1) distribution of 48%/8%/44%.

POL ran 283 (75.9) min·wk-1 and 47.3 (11.6) km·wk-1, both exceeding the 117 (32.2) min·wk-1 and 19.3 (7.17) km·wk-1 in CFE (P < .001). The POL distribution (74%/11%/15%) had greater total and percentage Z1 (P < .001) than CFE (46%/15%/39%), which featured higher percentage Z3 (P < .001). Time trial improved -93.8 (40.4) s (-6.21% [2.16%]) in POL (P < .001) and -84.2 (65.7) s (-5.49% [3.56%]) in CFE (P = .001). BC improved by -2.45% (2.59%) fat in POL (P = .02) and -2.62% (2.53%) in CFE (P = .04). The magnitude of improvement was not different between groups for time trial (P = .79) or BC (P = .88). Both groups increased VO2max (P ≤ .01), but with larger magnitude (P = .04, d = 0.85) in POL (4.3 [3.6] mL·kg·min-1) than CFE (1.78 [1.9] mL·kg·min-1).

Recreational runners achieved similar improvement in 5-km performance and BC through polarized training or CFE, but POL yielded a greater increase in VO2max. Extrapolation to longer distances requires additional research.