First, remember one of the initial responses to altitude is dehydration. Because the athlete's hydration state is critical to overall performance, each swimmer should drink before, during and after practice. The athletes' ability to maintain appropriate hydration should be monitored during their training. A simple method is to weigh the swimmer each morning. Attempt to weigh the swimmers at the same time of day.
Women fluctuate body weight in response to their menstrual cycle.
The difference in body weight before and after practice indicates the athlete may not have ingested enough fluids during the practice. Declines in body weight over several days suggest potential chronic dehydration that should be corrected immediately. Second, allow for several days of adjustment to the new environment prior to beginning intense training. The athletes in the distance camp had heart rates measured during the workouts. Over the course of the camp, the group was able to work at a more intense level.