Altitude Research
Research paper Summaries
Clanton TL, & PF Klatwitter. Adaptive responses of skeletal muscle to intermittent hypoxia. J Appl Physiol90(6):2476-2487, 2001.
Results
Low level hypoxia shifts the metabolic enzyme activity of skeletal muscle towards greater aerobic poise, whereas extreme hypoxia shifts metabolism towards greater anaerobic potential. Some conditions of intermittent hypoxia inhibit lactate release during exercise. The net effect of a variety of skeletal muscle adaptive mechanisms to intermittent hypoxia is to preserve contractile function and cell integrity in hypoxia, and translates into improvements in exercise performance.
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Liu Y, Steinacker JM, Dehnert C, et al. Effect of "living high - training low" on the cardiac functions at sea level. Int J Sports Med19:380-384, 1998.
Results
Comparison of control (living and training at sea level) and treatment (living high, training at sea level) groups demonstrated that the high-low group had significant improvements in cardiac function. Stoke volume, cardiac output, shortening fraction, and ejection fraction all increased significantly in the high-low group. These results demonstrate that living high but training low produced a significant improvement in overall cardiac function and improved myocardial energy utilization.
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Howe D, & GD Swanson. Athletic performance and altitude response in horses exposed to simulated high altitude (3658 m). Presented at 13th Annual International Hypoxia Symposium. Banff, Alberta, Canada. February 19th - 22nd, 2003.
Results
Using a crossover experimental design horses were kept at sea level for 4 weeks followed by 4 weeks at a simulated altitude of 3658m (8 hours per day) in an altitude simulation stall. Pre- and post-altitude athletic parameters were tested using a stationary treadmill. Post-altitude exposure the horses had significant (+11%) increases in V200 time (a measure of aerobic power output), time at maximal running speed (increased by 60 seconds), and faster heart rate recovery following maximal exercise stress test (18% faster recovery). This study demonstrates that high-low training using an altitude simulation system is an effective training aid to increase aerobic fitness and performance, and leads to improved recovery rates following intensive training.
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Wickler SJ, & TP Anderson. Hematological changes in athletic performance in horses in response to high altitude (3800 m). Am J Physiol Regulatory Integrative Comp Physiol279:R1176-R1181, 2000.
Results
Following high altitude acclimatization (3800m) six horses underwent post-exposure testing to determine the effect of acclimatization on standard hematological indices as well as low altitude athletic performance. Following 9 days of exposure to 3800 meters the horses had significant increases in red blood cell volume and 2,3 diphosphoglycerate/hemoglobin concentrations. Following high altitude acclimatization heart rate recovery post-exercise and lactate recovery were significantly faster, demonstrating improved aerobic performance at lower elevations.
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Foreman H, Waldsmith JK, & RB Lalum. Environmental stress and 3-day eventing: Effects of altitude. Eq Vet J, Suppl. 30:394-397, 1999.
Results
The effect of 3-day eventing at high altitude was studied on 24 mature eventing horses at 1900 meters (6200 feet) above sea level. At 1900m horses had significantly greater work effort from both a cardiopulmonary and metabolic perspective in comparison to horses competing at similar distances and velocities at sea level. The conclusion was that increased altitude was physiologically more stressful for 3-day event horses than competition at sea level. High-Low training negates the stresses associated with high altitude training. Altitude simulation to pre-acclimate horses may be beneficial in reducing the increased workload at altitude and reduce the physiological stress associated with competition at higher elevations. | 
