ORIGINAL ARTICLE M. Burtscher · W. Nachbauer · P. Baumgartl M. Philadelphy Benefits of training at moderate altitude versus sea level training in amateur runners Accepted: 15 July 1996 Abstract After more than 25 years of research on alti- tude training (AT) there is no consensus regarding either the training programme at altitude or the effects of AT on performance at sea level. Based on a review of the research work on AT, we investigated combined base training and interval training at moderate altitude and compared immediate and delayed effects on sea level performance with those following similar sea level training (SLT). The altitude group (AG, 10 male ama- teur runners) trained at 2315 m (natural altitude) and the sea level group (SLG, 12 male amateur runners) at 187 m. Both groups performed 7 days of base training (running on a trail) lasting between 60 and 90 min a day and 5 days of interval training (speed and hill runs) for between 10 and 45 min 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 training 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 oxygen uptake (V ˙ O 2max ) increased from t 2 to t 3 by 10% (P < 0.05). Within SLG exercise performance increased from t 2 to t 3 by 8% (P < 0.05). At t 3 , relative and absolute V ˙ O 2max in AG were significantly higher in comparison with SLG (P = 0.005 and P = 0.046 re- spectively). The improved performance 3 days after AT may be explained in part by an increased oxygen uptake at submaximal exercise intensities without a change in V ˙ O 2max . Further enhancement in performance 2 weeks after AT, however, seems to have been due to the clearly enhanced V ˙ O 2max . Progressive cardiovascular adjust- ments might have contributed primarily to the time-de- pendent improvements observed after AT, possibly by an enhanced stroke volume overcompensating the re- duced heart rates during submaximal exercise. In con- clusion, 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 intensity by training at con- stant heart rates during acclimatization at altitude would seem to be a successful training regimen for amateur runners. Most beneficial effects became apparent during the subsequent SLT around 2 weeks after return from altitude. Therefore, we are convinced that AT should be reconsidered as a potent tool for enhancing aerobic ca- pacity, at least in non-elite athletes. Key words Altitude training · Sea level training · Maximal oxygen uptake · Cardiovascular adjustment Introduction The effects of training at altitude (AT) have been stu- died for more than 25 years. An important issue is whether AT enhances performance above similar sea level training (SLT), and if so, whether this could be an advantage in subsequent training at sea level or com- petitions at altitude and/or at sea level. The optimal altitude for training, the training programme and the duration of readaptation after return from altitude are apparently the most significant factors in the practice of AT. A review of the many research studies of the last 3 decades, would seem to suggest a consensus that the appropriate training altitude ranges between 2000 m and 3000 m (Balke et al. 1966; Mellerowicz et al. 1970; Suslov 1983; Po ¨hlitz 1986; Dick 1992; Levine and Stray- Gunderson 1992). There has also been conformity concerning the benefit of AT in preparing an athlete for competition at altitude (Pugh et al. 1964; Terrados et al. 1988; Levine et al. 1990; Dick 1992; Levine and Stray- Gunderson 1992). However, some basic problems still remain unresolved, above all those regarding the most Eur J Appl Physiol (1996) 74: 558 – 563  Springer-Verlag 1996 M. Burtscher (&) · W. Nachbauer Department of Sport Science, University of Innsbruck, Fu ¨ rstenweg 185, A-6020 Innsbruck, Austria P. Baumgartl Department of Sports Medicine, General Hospital, St. Johann, Tyrol, Austria M. Philadelphy Health Section, Austrian Alpine Club, Innsbruck, Austria