Glucose Turn Point as a Marker of Exercise Intensity in Elite Swimmers

Abstract

Purpose: To investigate a blood glucose profile and turn point during incremental exercise.Methods: Thirty-three national and international-level swimmers undertook a 7 × 200 m discontinuous, incremental, training set on a six-minute turnaround. Subjects were asked to be two hours post-absorptive, which resulted in a mean blood glucose level of 5.5 ± 0.57 mmol/l. After each 200 m-swim blood lactate, blood glucose, and heart rate were taken and values plotted against the velocity of each swim. A Glucose turn point (Gt) was observed and defined in this study as an upward deflection after which blood glucose continues to rise. The Dmax, Borch, and LogLog methods were used to calculate Anaerobic Threshold (AnT).