| This purpose of this study was to determine the day-to-day reliability of resting metabolic rate. 18 college students, (mean age 22 +/- 3.6 yrs, height 65.78 +/- 22.0 in., body mass 68.05 +/- 10.34 kg, percent body fat 23 +/- 6.5%) gave informed consent to participate in the study. RMR was measured on four separate days over a period of 14 days. Height, weight, and resting heart rate were also recorded on each testing day. Body composition was assessed on the first day. Energy intake, energy expenditure, and caffeine intake were controlled between days. Each test was done between 7 and 9 AM each morning, and RMR was measured by open circuit spirometry over a 35-minute period. Reliability was assessed using an Intraclass Correlation Coefficient. The reliability across days was R = 0.97. The overall mean VO2 was 3.35 +/- .77 ml/kg/min. The mean VO2 was 3.34 +/- .35 ml/kg/min on day one, 3.29 +/- .29 ml kg-1&dotbelow; min-1 on day two, 3.36 +/- .37 ml kg-1&dotbelow; min-1 on day three, and 3.37 +/- .50 ml kg-1&dotbelow; min -1 on day four. This study demonstrates that under controlled conditions, resting metabolic rate is a very stable measurement. Therefore, under these conditions, a single RMR measurement can be considered an estimate of the individual's true RMR, and confidence can be placed in that measurement. |
