Purpose: This test is to investigate the effect of water and glucose solution, during moderate intensity exercise on post-exercise appetite. Methods: A male participate (Age: 24yr; BMI: 20.5kg/m2; VO2max: 57.7ml/kg/min) completed one preliminary VO2max test first. After that, complete two main trials separately with different solution. Participant had to cycling at 55% VO2max for 30 minutes and resting 30 minutes. During the whole experimental period, participant consumed total three times solution at the beginning, 15th minutes and 30th minutes of the test. Moreover, body weight, blood sample and appetite test scores were collected in different period of time. Results: During and after the exercise, the blood glucose of G trial is higher than that in W trial (G trial at 15th minutes 4.9mmol/L; W trial at 15th minutes: 4.7mmol/L). In addition, the appetite score was lower in G trial than that in W trial during resting period (G trial at 60th minutes: 65; W trial at 60th minutes: 72). Conclusion: Compared with glucose solution and water, glucose consumption caused lower blood glucose during exercise and resting period, at the same time, the appetite score after intake of glucose lower than water consumption. However, the result was not convincing enough to conclude that the lower blood glucose concentration will result higher appetite due to the limitation of food intake before the test.
Recent evidences showed the source of energy may affect the short-term appetite, for example, the glycemic index (Bornet, Jardy-Gennetier, Jacquet, & Stowell, 2007; Livesey, 2005). Moreover, traditional glucostatic theory has mentioned the casual relationship between glycaemia and short-term appetite (Mayer, 1953). The appetite was stimulated when glycaemia drop below a static level. A recent review found similar result (Chaput & Tremblay, 2009). In addition, the transient and dynamic fall of glycaemia could signal sense of appetite (Arumugam et al., 2008) and meal initiation (Smith & Campfield, 1993). However, little studies investigate the solution consumed during exercise will affect the post-exercise food intake or not. Therefore, this research is to investigate the effects of consuming water and glucose solution during moderate intensity exercise, how they affect the post-exercise appetite.
A healthy male volunteered to participate in the study. His age was 24 years old, height 180cm, weight 66.4kg, body mass index (BMI) 20.5kg/m2 and VO2max 57.7mLkg-1min-1. Participant was required to complete medical-history questionnaires. Participate had moderate levels of physical activity. Participant gave his written informed consent.
Subject required completing one preliminary test which is VO2max test. The purpose of the preliminary test is to determine the VO2max value and decide the exercise intensity which is equals to 55% VO2max. The 55% VO2max will be used in the later main trial tests.