The Valsalva maneuver is performed by forceful attempted exhalation against a closed airway, usually done by closing one's mouth, pinching one's nose shut while pressing out as if blowing up a balloon. This is also present under exertion during severe coughing, straining on the toilet, blowing musical instruments (trumpet), bodybuilding, giving birth and exercise! The exercise element is the part I want to concentrate on, but first we need to understand the mechanics of what is going on!
A bit of science first - The normal physiological response consists of four phases.
1. Initial pressure rise - On application of expiratory force, pressure rises inside the chest forcing blood out of the pulmonary circulation into the left atrium. This causes a mild rise in stroke volume during the first few seconds of the maneuver.
2. Reduced venous return and compensation - Return of systemic blood to the heart is impeded by the pressure inside the chest. The output of the heart is reduced and stroke volume falls. The fall in stroke volume reflexively causes blood vessels to constrict with a rise in pressure, this compensation can be quite marked. During this time the pulse rate increases.
3. Pressure release - The pressure on the chest is released, allowing the pulmonary vessels and the aorta to re-expand causing a further initial slight fall in stroke volume (20 to 23 seconds) due to decreased left atrial return and increased aortic volume, respectively. Venous blood can once more enter the chest and the heart, cardiac output begins to increase.
4. Return of cardiac output - Blood return to the heart is enhanced by the effect of entry of blood which had been dammed back, causing a rapid increase in cardiac output. The stroke volume usually rises above normal before returning to a normal level. With return of blood pressure, the pulse rate returns towards normal.
So basically, as we have a concentrated exertion whilst performing an explosive type activity our blood pressure rises dramatically, this can be lifting heavy weights or preparing for an explosive technique such as a jumping or power kicking technique or power hand technique. Valsalva maneuver was previously believed to increase the trunk stability and strength during resistance (powerlifting) exercises, such as squat, deadlift and bench press, but this has not been confirmed by studies. Blood pressure as high as 480/350 mm Hg during weightlifting using Valsalva has been observed (this is very very high!!!) This exertion response has medical risks to it.
Complications of Valsalva maneuvers during exercise:
Bleeding from the nose or ears
Burst blood vessels in the eye
Detachment of the retina
Valsalva retinopathy, bleeding in front of the retina (the membrane that lines the eyeball and enables vision) temporary vision loss and floaters in the visual field.
Spontaneous cerebrospinal fluid (CFS) leak (clear liquid dropping out from one nostril)
Fainting
Transient global amnesia: temporary (<24 hours) confusion due to severe memory loss after repeated Valsalva maneuvers
Brain bleeding (Stroke)
Heart attack in individuals with heart disease
Conclusion:
All the above is quite heavy and worrying, however we can’t stop exercising and doing what we enjoy, and as you have heard just coughing, vomiting or straining on the toilet can cause an issue and you’re not going to stop those!!! But what we can do is minimize the risks by practicing good technique when exercising etc.
Creating core stability and keeping tension in the core muscles is vital to good technique.
However, breathing out rather than holding your breath during the exertion is the major key to alleviating this issue
Don’t over load your system to a point beyond your abilities
And lastly the reason for this post, that is a picture of my eye after having a vomiting episode earlier this week, I have also, many years back, had a CVA (stroke) from maximal exercise exertion testing which caused a Valsalva maneuver! Even the healthiest and fittest can be at risk!
