How is water exercise different from land exercise?
Positive effects of buoyancy
- In the water your body is buoyant and the impact to the joints during exercise is significantly less than on land. Depending upon the water depth, your body “weight” is reduced in the pool due to lessened gravitational forces.
- A body immersed to the neck bears approximately 10% of its body weight.
- A body immersed to the chest bears approximately 25-35% of its body weight.
- A body immersed to the waist bears approximately 50% of its body weight.
- A properly designed program in the water provides a highly effective workout in a safe and gentle environment due to the principle of buoyancy. Shallow water programs are generally best performed in water that is about mid-chest depth for maximum comfort, control of movement and optimum toning benefits for the upper body.
Positive effects of resistance
- Muscles must work against resistance to become developed and toned. Water provides substantially more resistance than air because it is a thicker medium than air, making each movement in the pool more challenging to the muscles. Also, muscles typically work in pairs; i.e. biceps & triceps or quadriceps & hamstrings.
- When you move your body or your limbs through the water, you are always encountering resistance. This helps to provide a more balanced workout as opposing muscles are involved, unlike on land where you typically need to reposition the body, or select a separate exercise, to provide adequate stimulation to both muscles of the pair.
NOTE: If you incorporate weighted, buoyant or rubberized equipment, these muscle actions will change and it once again becomes necessary to target both muscles of a pair with separate exercises!
Positive effects of hydrostatic pressure
- The hydrostatic pressure in water is 800 times higher than on land. This natural, soft and regular massage aids the venous return of blood to the heart.
- Hydrostatic pressure reduces swelling in injured or oedematous (swollen) joints or limbs below the water.
- The pressure of water on the chest wall creates a training effect for the respiratory muscles.
- Hydrostatic pressure assists participants to exercise more vigorously with less strain on the cardiovascular system and a reduced training heart rate for a given workload.
Positive effects of heart rate
- Heart rate responses differ when exercising in the water than when exercising on land. Typically, aquatic exercisers experience a reduced heart rate response (i.e. lowered pulse rate), but the water should not be considered less effective. Studies have shown that oxygen consumption (the true measure of the cardiovascular benefits) is comparable to a similar program on land, although the heart rate response is lower. Several factors, some of which have been previously mentioned, influence the exercising heart rate when submerged in the water to mid-chest:
- Lessened gravity allows a more efficient return of blood to the heart from the extremities.
- The cooling effect of water reduces the workload on the heart. (One function of the heart is to keep the body cool during sustained exercise.)
Positive effects of turbulence
- Currents and eddies in the water massage the skin, promoting circulation and relaxation.
- Turbulence contributes to the resistance felt in aquatic exercise.
- The core muscles become stronger as participants learn to stabilize their bodies against turbulence. Exercises can be designed to work with or against turbulence, thereby increasing or decreasing intensity
Positive effects of thermal conductivity
- Water cools more efficiently than air, so when exercising in the water the body is able to eliminate excess heat more effectively. This is not to say that you will not sweat during a workout in the pool, but water helps prevent overheating and washes away the perspiration as you exercise.
- Because the water cools the body quickly, it is imperative that you begin every workout with a “thermal warm up” designed to elevate the body’s core temperature, warm the muscles and prepare the joints, even at the recommended temperature of 26-32 degrees Celsius.