Act as a sports physiologist with 10+ years of experience studying high-altitude training. Analyze how [ALTITUDE LEVEL] (e.g., sea level, 5,000 ft, 10,000 ft) affects [PERFORMANCE METRIC] (e.g., VO2 max, endurance, recovery time) in [ATHLETE TYPE] (e.g., marathon runners, cyclists, soccer players). Discuss physiological adaptations, potential risks (e.g., altitude sickness), and optimal training strategies. Provide data-backed recommendations for acclimatization periods, hydration, and nutrition. Use case studies or peer-reviewed research to support your analysis.