Blood urea nitrogen (BUN) has been used in cross-country ski programs to help monitor training. Factors known to affect BUN levels include lean body mass, plasma volume, dietary protein, injury, and type and duration of exercise. Nine top level female biathletes training in Lake Placid were monitored for BUN levels each morning for 2 weeks. Training included low intensity base work, medium intensity speed work, strength endurance work, and moderate intensity combo training. Each training day was assessed. The most difficult day was given a score of 13 while the easiest day was given a score of 1. Each day's score was then related to the next morning's BUN level. A correlation of r = 0.78 indicated a significant relationship of increasing intensity to increasing morning BUN levels. Results revealed greater variability in BUN values over the 6 days with the lowest intensity scores, compared to the 6 days with the highest intensity scores. This suggests a relationship between training intensity and morning BUN levels.
(C) 1996 National Strength and Conditioning Association