Data analysis
Each minute of data was analyzed for the cold pressor test, and the 2 min of recovery for cold pressor and static handgrip were each averaged to a single value. Because the duration of handgrip was not constant between subjects and interventions, and since sympathetic and hemodynamic responses to static handgrip are dependent on fatigue and not actual duration, data are expressed as a percentage of total time and divided into four equal sections. Since the units for burst frequency are bursts/min, MSNA values for each stage of handgrip are normalized to 1 min.
A repeated measures analysis of variance (ANOVA) was conducted to determine the influence of caloric intake (calorie), ambulation vs bedrest (posture), and time during handgrip or cold pressor tests (stage) on MSNA and hemodynamic variables. Least squares means with Bonferroni correction were performed when appropriate to detect where differences between factors occurred. The level of significance was set at α= 0.05. Values are presented as mean ± SEM.