Validity of Sensewear Armband in the assessment of energy expenditure at different levels during menstrual cycle

The purpose of this study was to determine the validity of SenseWear Armband (SWA) in assessing the energy expenditure at different exercise intensities during midfollicular (MP) and luteal (LP) phases of the menstrual cycle. Twenty volunteer women sport school students (age=20.6±1.6 yrs; Menstrual cycle=28.8±2.1 days) with regular menstrual cycle participated in this study. Participants performed treadmill running exercise for 10 minutes at 35% and 75% of their VO2max in MP (7-9 days) and LP (21-23 days) of the menstrual cycle. The phases of the menstrual cycle were confirmed with hormonal analysis. Energy expenditure during running exercise was measured with indirect calorimetric method (ICM) and SWA. For data analysis 2x2x2 (Methods x Phase x Intensity) 3-way analysis of variance was used. Correlations among variables were determined with Pearson‟s r coefficient. No significant method and phase effect was found in energy expenditure (p>0.05). Energy expenditure at 75% intensity was significantly higher than energy expenditure at %35 intensity (p<0.05). There was no significant Method x Phase, Phase x Intensity, and Method x Phase x Intensity interaction effect (p>0.05), however Methods x Intensity interaction effect was significant (p<0.05). At MP the correlations between energy values from ICM and SWA was not significant (for 35% r=0.382, for 75% r=0.147, p>0.05). In contrast significant correlation was found between energy values from ICM and SWA at LP (for 35% r=0.495, for 75% r=0.748, p<0.05). The results of the present study indicated that energy expenditure at different menstrual phases was similar and SWA was a valid method assessing energy expenditure. Keywords: menstrual cycle, indirect calorimetry, sensewear armband, energy expenditure