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THE EFFECT OF HIGH INTENSITY HYPOXIC TRAINING ON SEA-LEVEL SWIMMING PERFORMANCES

2002; Lippincott Williams & Wilkins; Volume: 34; Issue: 5 Linguagem: Inglês

10.1097/00005768-200205001-01337

1530-0315

Martin J. Truijens, J. Dow, J Cabayo, Dean Palmer, S Witkowski, Paul Chase, Huub M. Toussaint, Benjamin D. Levine,

Cardiovascular and Diving-Related Complications

Altitude training is a function of both altitude acclimatization and hypoxic exercise. For endurance sports, the effect of acclimatization predominates and thus ôliving high û training lowö has been demonstrated to be the most effective strategy to improve sea level performance, with hypoxic exercise impairing rather than enhancing the performance advantage of this approach. However the effect of hypoxic training without altitude acclimatization remains controversial. We hypothesized that for sports of high intensity/short duration requiring high rates of ôanaerobicö metabolism to generate ATP independent of oxygen availability, the potential advantage of hypoxic exercise might be maximized. Moreover, because the mechanical efficiency of swimming is relatively low compared to running, cycling, or skiing, and most swimming events last less than 2 minutes, we speculated that a beneficial effect of hypoxic exercise could be best identified in swimmers. PURPOSE: The principal objective of this study was therefore to test the hypothesis that high intensity hypoxic training improves sea-level performances in well trained swimmers more than the equivalent training in normoxia. METHODS: After familiarization with testing and training techniques, sixteen collegiate and master swimmers (10 women, 6 men) participated in a 5 week training program, consisting of three high intensity training sessions in a flume and at least three low intensity sessions in a pool each week. Seven were current or former Olympians or competed in US Olympic trials, and nine others recently competed at US National Championships or Goodwill games. Subjects were matched for gender, performance level and training history, and assigned to either hypoxic (HYPO; FIO2 = 15.3%, simulated altitude of 2500m) or normoxic (NORM; FIO2 = 20.9%) interval training in a randomized, double blind, placebo controlled design. All low intensity training was done in a pool under normoxic conditions. The primary measure of performance was a 100m and 400m freestyle time-trial. RESULTS: Both groups improved significantly in performance on both the 100m (NORM: −0.74 sec, {95% conf limits +0.21 to −1.67 sec}, −1.2%; HYPO: −0.81 sec {−0.11 to −1.51 sec}, −1.1%) and 400m freestyle (NORM: −3.6 sec {−1.8 to −5.5 sec}, −1.2%; HYPO: −5.3 sec {−2.3 to −8.3 sec}, −1.7%). There was no significant difference between groups for either distance (ANOVA interaction p = 0.91 for 100m and p = 0.36 for 400m). CONCLUSION: Five weeks of high intensity training in a flume improves sea-level swimming performances in well-trained swimmers. We were unable to demonstrate a significant, additive effect of hypoxic training under the conditions of this rigorously controlled experiment.