Let s dive into intensity measurement in the pool. And, I ll share my own experience. According to the Aquatic Exercise Association s Aquatic Fitness Professional Manual, aquatic heart rates may be lower than heart rates achieved during comparable land exercise. This reduced effort means less work for the heart, resulting in a lower heart rate. Water reduces the effect of gravity on the body.
Blood flows from below the heart back up to it with less effort, resulting in a lowered heart rate.
The water is thought to act like a compressor on all body systems, including the vascular system, causing a smaller venous load to the heart than equivalent land exercise. In water exercise, the gas is oxygen and the liquid is the blood. So, more efficient gas transfer due to water pressure may reduce the workload of the heart. This is a primitive reflex associated with a nerve found in the nasal area. When the face is submerged in water, this reflex lowers heart rate and blood pressure.