Holding your breath during exercise (the Valsalva Maneuver) is bad for your heart and blood vessels because it causes unnecessary elevation of blood pressure, which could put you at risk of heart strain and stroke. Commonly personal trainers advise people to exhale during the concentric action of a repetition. According to the study, inhalation or exhalation to concentric or eccentric action made little or no difference with respect to blood pressure elevation during the lift. Inhalation during concentric action did show a slight increase in heart rate compared to exhalation during concentric action. Another study has shown that blood pressure during heavy lifting is higher during concentric action in a repetition — compared to eccentric action during a repetition, reporting systolic and diastolic blood pressures rose rapidly to extremely high values during the concentric contraction phase for each lift and declined with the eccentric contraction. This could be due to less effort required as the internal frictional affect in muscle during lowering of the weight in an eccentric action.
Effect of breathing techniques on blood pressure response to resistance exercise.
Twenty novice male weight lifters performed resistance exercises using three different breathing techniques to determine the effects on blood pressure. Systolic and diastolic blood pressures were measured by an automated non-invasive method while subjects performed the single arm curl and double knee extension using the different breathing techniques. Performing the Valsalva manoeuvre (breath-holding) during either the single arm curl or double knee extension produced the highest blood pressure responses. Inhaling during the concentric phase of the exercise was associated with blood pressure elevations that were similar to the elevations observed with exhaling during the concentric phase. The heart rate response was slightly higher with inhalation. These results suggest that performing the Valsalva manoeuvre exaggerates the blood pressure response to resistance exercise. In addition, coupling inhalation with the concentric phase of the lift offers no cardiovascular advantage over coupling exhalation with the concentric phase of the lift.
PMID: 1623367 [PubMed – indexed for MEDLINE]