Walking in water is a popular low-impact form of exercise that offers the benefits of cardio and resistance training simultaneously. This activity involves walking while partially or fully immersed in a pool, creating a unique environment for physical activity. It is a favored choice for many people, especially those seeking a gentler alternative to land-based exercises, because the water supports the body. The fundamental question is how many calories they can expect to burn and what factors influence that expenditure.
Baseline Calorie Burn Rates
The number of calories burned while water walking is significantly higher than walking on land, thanks to the water’s natural resistance. For a person weighing 155 pounds, light-effort water walking (a slow pace) may burn around 211 calories per hour. This effort level is comparable to light resistance or water calisthenics. Increasing the effort to a moderate pace can raise the hourly calorie expenditure to between 320 and 430 calories. A vigorous effort, involving a brisk pace in chest-deep water, can result in burning approximately 487 to 500 calories per hour. These numbers are estimates, as individual body weight and the exact depth of the water will cause the actual burn rate to vary.
The Mechanics of Water Resistance
The significantly greater calorie burn is a direct result of the unique physical properties of water acting on the body during movement. Water’s density and viscosity are much greater than air, which creates a force known as hydrodynamic drag. This drag is the resistance a moving body encounters in the fluid, compelling the muscles to work harder to propel the body forward than they would on land.
Buoyancy, the upward thrust exerted by the water, reduces the effect of gravity and lessens the load on joints. While this makes the exercise low-impact and easier on the body, it also requires stabilizing muscles to work continuously to maintain balance and proper posture. For instance, a person immersed in water up to the chest will bear only about 25% of their body weight, greatly minimizing joint compression.
Hydrostatic pressure is the pressure exerted by the water equally on all submerged surfaces of the body. This pressure increases proportionally with depth, meaning the lower limbs experience more pressure than the chest. This constant, enveloping pressure aids in circulation and requires the body to exert energy against this external force with every movement.
Increasing Energy Expenditure
To maximize calorie burn during a water walking session, manipulating speed, depth, and resistance is most effective. Increasing the speed or cadence of the walk dramatically boosts energy expenditure because hydrodynamic drag increases with velocity. Running or jogging in the water, for example, can burn 50-100% more calories than a standard water walk.
Adjusting the water depth changes the amount of body weight supported and the surface area exposed to resistance. Walking in waist-deep water engages the leg muscles more as they bear approximately 50% of the body’s weight. Conversely, moving to chest-deep water increases the submerged area, maximizing full-body drag resistance.
Incorporating upper body movements or external tools introduces additional resistance and engages more muscle groups. Swinging the arms vigorously or performing high-knee movements increases the surface area pushing against the water, thereby increasing drag and calorie burn. Hand paddles, resistance gloves, or water dumbbells can be used to create greater resistance for the arms and core, further intensifying the workout.