No effects of glycogen depleting exercise and altered diet composition on mood states

Abstract

To investigate the effects of glycogen depleting exercise and dietary composition on mood, 14 males completed the Profile of Mood States (POMS) questionnaire under four conditions. A control condition (CON) of ad libitum diet preceded any experimental manipulation. Subsequently, three treatments were administered randomly in a counterbalanced design: a) following a glycogen-depletion protocol and 3 d on a high-carbohydrate diet (93% of total caloric intake as carbohydrate [CHO]), b) following a glycogen-depletion protocol and 3 d on a low-CHO diet (23% of total caloric intake as CHO), and c) following 3 d of recorded ad libitum dietary consumption. Conditions a and b simulated phases of popular glycogen-loading protocols, and condition c served as a second control condition confirmed by records of dietary intake. The POMS measured tension-anxiety, depression-dejection, anger-hostility, vigor-activity, fatigue-inertia, and confusion-bewilderment. A composite score of total mood disturbance (TMD) was computed by summing the subscale scores (weighting vigor-activity negatively). Dietary composition (fat, protein, and CHO content) differed significantly (P less than 0.001) among the three treatments, but total caloric intake was not different. No significant differences were found among the treatment and control conditions for TMD or any POMS subscale score. We find no evidence that the 3-d glycogen loading protocol we employed with healthy, moderately fit, young males can be expected to confound performance measures by altering mood.