A longitudinal study on the ammonia threshold in junior cyclists.

OBJECTIVES To identify the effect of a one year non-specific training programme on the ammonia threshold of a group of junior cyclists and to correlate ammonia threshold with other common physiological variables. METHODS The cyclists performed tests at three time points (T1, T2, T3) during the year. Follow up tests were conducted every six months after the original test. Ammonia threshold was obtained from a graded exercise with four minute steps. RESULTS The relatively non-specific one year training programme was effective in inducing an increase in peak VO(2) (60.6 (5.9), 65.9 (7.4), and 64.6 (6.5) ml/min/kg at T1, T2, and T3 respectively) and endurance time (18.3 (4.5), 20.1 (5.2), and 27.0 (6.1) minutes at T1, T2, and T3 respectively), but was not effective for the sprint related variables. Ammonia threshold, together with lactate threshold and ventilatory threshold, was not significantly different at the three test times. Only endurance time correlated significantly with ammonia threshold (r = 0.915, p = 0.001). CONCLUSIONS The findings suggest that a relatively non-specific one year training programme does not modify the ammonia threshold of junior cyclists. The significant correlation between ammonia threshold and endurance time further confirms that ammonia threshold is a measure of the ability to sustain exercise at submaximal intensities.