Overspeed HIIT in Lower-Body Positive Pressure Treadmill Improves Running Performance.

• Autores: Boris Gojanovic, Rebecca Shultz, Francois Feihl, Gordon O. Matheson
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 47, Nº. 12, 2015, págs. 2571-2578
• Idioma: inglés
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• Resumen

  • AB Purpose: Optimal high-intensity interval training (HIIT) regimens for running performance are unknown, although most protocols result in some benefit to key performance factors (running economy (RE), anaerobic threshold (AT), or maximal oxygen uptake (V[spacing dot above]O2max)). Lower-body positive pressure (LBPP) treadmills offer the unique possibility to partially unload runners and reach supramaximal speeds. We studied the use of LBPP to test an overspeed HIIT protocol in trained runners. Methods: Eleven trained runners (35 +/- 8 yr, V[spacing dot above]O2max, 55.7 +/- 6.4 mL[middle dot]kg-1[middle dot]min-1) were randomized to an LBPP (n = 6) or a regular treadmill (CON, n = 5), eight sessions over 4 wk of HIIT program. Four to five intervals were run at 100% of velocity at V[spacing dot above]O2max (vV[spacing dot above]O2max) during 60% of time to exhaustion at vV[spacing dot above]O2max (Tlim) with a 1:1 work:recovery ratio. Performance outcomes were 2-mile track time trial, V[spacing dot above]O2max, vV[spacing dot above]O2max, vAT, Tlim, and RE. LBPP sessions were carried out at 90% body weight. Results: Group-time effects were present for vV[spacing dot above]O2max (CON, 17.5 vs. 18.3, P = 0.03; LBPP, 19.7 vs. 22.3 km[middle dot]h-1; P < 0.001) and Tlim (CON, 307.0 vs. 404.4 s, P = 0.28; LBPP, 444.5 vs. 855.5, P < 0.001). Simple main effects for time were present for field performance (CON, -18; LBPP, -25 s; P = 0.002), V[spacing dot above]O2max (CON, 57.6 vs. 59.6; LBPP, 54.1 vs. 55.1 mL[middle dot]kg-1[middle dot]min-1; P = 0.04) and submaximal HR (157.7 vs. 154.3 and 151.4 vs. 148.5 bpm; P = 0.002). RE was unchanged. Conclusions: A 4-wk HIIT protocol at 100% vV[spacing dot above]O2max improves field performance, vV[spacing dot above]O2max, V[spacing dot above]O2max and submaximal HR in trained runners. Improvements are similar if intervals are run on a regular treadmill or at higher speeds on a LPBB treadmill with 10% body weight reduction. LBPP could provide an alternative for taxing HIIT sessions.