BENEFITS OF TRAINING AT MODERATE ALTITUDE VERSUS SEA-LEVEL TRAINING IN AMATEUR RUNNERS

After more than 25 years of research on altitude training (AT) there i s no consensus regarding either the training programme at altitude or the effects of AT on performance at sea level. Based on a review of th e research work on AT, we investigated combined base training and inte rval training at moderate altitude and compared immediate and delayed effects on sea level performance with those following similar sea leve l training (SLT). The altitude group (AG, 10 male amateur runners) tra ined at 2315 m (natural altitude) and the sea level group (SLG, 12 mal e amateur runners) at 187 m. Both groups performed 7 days of base trai ning (running on a trail) lasting between 60 and 90 min a day and 5 da ys of interval training (speed and hill runs) for between 10 and 45 mi n a day. Incremental exercise tests were performed 1 week before (t(1) ), 3 days after (t(2)) and 16 days after (t(3)) the 12-day main traini ng period. Within AG, exercise performance improved from t(1) to t(2) by 8% (P < 0.05) and from t(2) to t(3) by 8% (P < 0.05). Maximum oxyge n uptake (VO2max) increased from t(2) to t(3) by 10% (P < 0.05). Withi n SLG exercise performance increased from t(2) to t(3) by 8% (P < 0.05 ). At t(3), relative and absolute VO2max in AG were significantly high er in comparison with SLG (P = 0.005 and P = 0.046 respectively). The improved performance 3 days after AT may be explained in part by an in creased oxygen uptake at submaximal exercise intensities without a cha nge in VO2max. Further enhancement in performance 2 weeks after AT. ho wever, seems to have been due to the clearly enhanced VO2max. Progress ive cardiovascular adjustments might have contributed primarily to the time-dependent improvements observed after AT, possibly by an enhance d stroke volume overcompensating the reduced heart rates during submax imal exercise. In conclusion, our findings would suggest that training at a moderate natural altitude improves performance at sea level more than SLT. Combining base and interval training with regulation of int ensity by training at constant heart rates during acclimatization at a ltitude would seem to be a successful training regimen for amateur run ners. Most beneficial effects became apparent during the subsequent SL T around 2 weeks after return from altitude. Therefore, we are convinc ed that AT should be reconsidered as a potent tool for enhancing aerob ic capacity, at least in non-elite athletes.