Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey; Institute for Health and Sport, Victoria University, Melbourne, VIA 3011, Australia.
Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey.
J Sport Health Sci. 2021 Jul;10(4):478-487. doi: 10.1016/j.jshs.2020.06.008. Epub 2020 Jun 18.
High-intensity interval training (HIIT) induces similar or even superior adaptations compared to continuous endurance training. Indeed, just 6 HIIT sessions over 2 weeks significantly improves maximal oxygen uptake (VO), submaximal exercise fat oxidation, and endurance performance. Whether even faster adaptations can be achieved with HIIT is not known. Thus, we aimed to determine whether 2 sessions of HIIT per day, separated by 3 h, every other day for 5 days (double HIIT (HIIT-D), n = 15) could increase VO, submaximal exercise fat oxidation, and endurance capacity as effectively as 6 sessions of HIIT over 2 weeks (single HIIT (HIIT-S), n = 13).
Each training session consisted of 10 × 60 s of cycling at 100% of VO interspersed with 75 s of low-intensity cycling at 60 watt (W). Pre- and post-training assessments included VO, time to exhaustion at ∼80% of VO, and 60-min cycling trials at ∼67% of VO.
Similar increases (p < 0.05) in VO (HIIT-D: 7.7% vs. HIIT-S: 6.0%, p > 0.05) and endurance capacity (HIIT-D: 80.1% vs. HIIT-S: 79.2%, p > 0.05) were observed. Submaximal exercise carbohydrate oxidation was reduced in the 2 groups after exercise training (HIIT-D: 9.2%, p = 0.014 vs. HIIT-S: 18.8%, p = 0.012) while submaximal exercise fat oxidation was significantly increased in HIIT-D (15.5%, p = 0.048) but not in HIIT-S (9.3%, p = 0.290).
Six HIIT sessions over 5 days was as effective in increasing VO and endurance capacity and was more effective in improving submaximal exercise fat oxidation than 6 HIIT sessions over 2 weeks.
高强度间歇训练（HIIT）引起的适应与持续耐力训练相似甚至更好。事实上，仅需进行 2 周 6 次 HIIT 训练，就可显著提高最大摄氧量（VO）、亚极量运动脂肪氧化和耐力表现。但是否可以通过 HIIT 更快地适应，目前尚不清楚。因此，我们旨在确定每天进行 2 次 HIIT，每次间隔 3 小时，每隔一天进行 5 天（双 HIIT（HIIT-D），n=15）是否可以像 2 周内进行 6 次 HIIT 一样有效地增加 VO、亚极量运动脂肪氧化和耐力能力（单 HIIT（HIIT-S），n=13）。
每次训练包括 10 次 100% VO 自行车运动，每次 60 秒，穿插 75 秒低强度自行车运动，功率为 60 瓦（W）。训练前后的评估包括 VO、约 80% VO 的力竭时间和约 67% VO 的 60 分钟自行车测试。
观察到 VO（HIIT-D：7.7%比 HIIT-S：6.0%，p＞0.05）和耐力能力（HIIT-D：80.1%比 HIIT-S：79.2%，p＞0.05）的相似增加。两组运动训练后，亚极量运动碳水化合物氧化均降低（HIIT-D：9.2%，p=0.014 比 HIIT-S：18.8%，p=0.012），而 HIIT-D 中亚极量运动脂肪氧化明显增加（15.5%，p=0.048），但 HIIT-S 中无明显变化（9.3%，p=0.290）。
与 2 周内进行 6 次 HIIT 相比，5 天内进行 6 次 HIIT 更有效地增加 VO 和耐力能力，并且更有效地改善亚极量运动脂肪氧化。
