[Oxygen peak consumption is a better predictor of cardiovascular risk than handgrip strength in older Chilean women]

BACKGROUND

Handgrip strength (HS) and peak oxygen consumption (Vo2peak) are powerful predictors of cardiovascular risk, although it is unknown which of the two variables is the better predictor.

AIM

The objective of the following study was to relate HS and Vo2peak to cardiovascular risk markers in older Chilean women.

METHODS

Physically active adult women (n=51; age, 69±4.7years) participated in this study. The HS and Vo2peak were evaluated and related to the anthropometric variables of body mass, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist ratio (WR), and waist height ratio (WHR), as well as with the cardiovascular variables systolic (SBP) and diastolic (DBP) and cardiac recovery in one minute (RHR1). A multilinear regression model was used for the analysis of the associated variables (P<.05).

RESULTS

The cardiovascular risk markers associated (P<.05) with the handgrip strength of the dominant limb (HS_DL) were body mass, BMI, WR, and WHR. The handgrip strength of the non-dominant limb (HS_NDL) was associated with body mass. Vo2peak was associated with body mass, BMI, HC and RHR1. The multilinear regression model showed a value of r=0.43 in HS_DL, r=0.39 in HS_NDL and r=0.69 in peak Vo2.

CONCLUSION

Although HS and Vo2peak were related to cardiovascular risk markers, Vo2peak offers greater associative power with these cardiovascular risk factors.

Hydration status after exercise affect resting metabolic rate and heart rate variability

INTRODUCTION

Heart rate variability and resting metabolic rate are commonly to assess athlete's physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human's homeostasis.

OBJECTIVES

To compare the effects of dehydration and rehydration after exercise on heart rate variability and resting metabolic rate in college athletes.

METHODS

14 college athletes were divided into a dehydration group (n=7) and a rehydration group (n=7), both submitted to basal (T1) heart rate variability and resting metabolic rate measurements. After basal measurements both groups were actively dehydrated (-3.4 ± 0.4% of body mass for both groups). Afterwards, dehydration group rested, while rehydration group receive a fluid intake (during a 3 h period) equivalent to 150% of body mass loss achieved during active dehydration. Four hours after active dehydration heart rate variability and resting metabolic rate were re-assessed (T2).

RESULTS

At T2 both rehydration group (+13%) and dehydration group (+30%) achieve a significant (p<0.05) increase in resting metabolic rate, however, only dehydration group ..showed a significant reduction in heart rate variability. More so, the change in resting metabolic rate was significantly higher in dehydration group compared to rehydration group.

DISCUSSION

Hydric homeostasis after exercise affects resting metabolic rate and heart rate variability, highlighting the necessity to control hydration state before resting metabolic rate and heart rate variability assessment.