RESUMO
The purpose of the study was to investigate the effects of one night's sleep deprivation on the cardiorespiratory responses to exercise during the follicular and luteal phases of the menstrual cycle. We have studied nine, healthy females aged 24-35 years with regular menstrual cycles. Each subject performed spirometric tests at rest and then an incremental exercise testing during 11-13 days of follicular phase and 22-24 days of luteal phase following one normal night's sleep or one night's sleep loss. Compared with resting values exercise produced significant increases in cardiorespiratory variables including oxygen uptake (VO2), carbon dioxide production (VCO2), tidal volume (VT), respiratory rate (RR), minute ventilation (VE), systolic blood pressure, heart rate (HR) and respiratory quotient (R). However, it did not alter significantly diastolic blood pressure, end-tidal PO2 (PETO2), end-tidal PCO2 (PETCO2) and arterial oxygen saturation (SaO2). Spirometric variables which include forced vital capacity (FVC), forced expiratory volume in one s (FEV1), FEV1/FVC%, forced expiratory volume in three s (FEV3), forced expired flow from 25-75% of FVC (FEF 25-75%), forced expired flow at 25% of FVC (FEF 25%), forced expired flow at 50% of FVC (FEF 50%), forced expired flow at 75% of FVC (FEF 75%), forced expired flow from 75-85% of FVC (FEF 75-85%), peak expiratory flow (PEF), expiratory reserve volume (ERV), inspiratory capacity (IC) and maximal voluntary ventilation (MVV) and cardiorespiratory variables were not different between the cycle phases after one normal night's sleep or one night's sleep deprivation. Neither menstrual cycle phase nor sleep deprivation affected spirometric and cardiorespiratory parameters. We suggest that one night's sleep deprivation does not produce alterations in spirometric parameters and cardiorespiratory responses to submaximal incremental exercise during the follicular and luteal phases.