The effect of an incremental increase in exercise on appetite, eating behaviour and energy balance in lean men and women feeding<i>ad libitum</i>

Abstract

The effects of incremental exercise on appetite, energy intake (EI), expenditure (EE) and balance (EB) in lean men and women were examined. Six men (age 29·7 ( sd 5·9) years, weight 75·2 ( sd 15·3) kg, height 1·75 ( sd 0·11) m) and six women (age 24·7 ( sd 5·9) years, weight 66·7 ( sd 9·10) kg, height 1·70 ( sd 0·09) m) were each studied three times during a 16 d protocol, corresponding to no additional exercise (Nex), moderate-intensity exercise (Mex; 1·5–2·0 MJ/d) and high-intensity exercise (Hex; 3·0–4·0 MJ/d) regimens. Subjects were fed to EB during days 1–2, and during days 3–16 they fed ad libitum from a medium-fat diet of constant composition. Daily EE, assessed using the doubly labelled water method, was 9·2, 11·6 and 13·7 MJ/d ( P &lt; 0·001; sed 0·45) for the women and 12·2, 14·0 and 16·7 MJ/d ( P = 0·007; sed 1·11) for the men on the Nex, Mex and Hex treatments, respectively. EI was 8·3, 8·6 and 9·9 MJ/d ( P = 0·118; sed 0·72) for the women and 10·6, 11·6 and 12·0 MJ/d ( P = 0·031; sed 0·47) for the men, respectively. On average, subjects compensated for about 30 % of the exercise-induced energy deficit. However, the degree of compensation varied considerably among individuals. The present study captured the initial compensation in EI for exercise-induced energy deficits. Total compensation would take a matter of weeks.