Walking in water without flotation increases your heart rate more than using a flotation device.
A water float helps people walking in the pool to maintain the same biomechanics they would use on land. But a flotation device won't help increase your heart rate and give you a better workout. A water float or flotation belt makes you more buoyant and, as a result, you won't have to work as hard to stay afloat while walking in deep water. In order to achieve a higher heart rate, you're better off walking without any flotation device.
Advantages of a Water Float
Wearing a flotation belt or vest while walking in deep water helps ensure you use the same muscles you use walking on dry land. Flotation allows you to concentrate on your form, and, if you aren't a strong swimmer, it can help you feel safer and more comfortable in deep water. The right kind of flotation will also allow you to avoid leaning forward too much.
The Advantages of Foregoing Flotation
Water walking or aqua jogging is more demanding when you don't use flotation. Without flotation, you are likely to walk at a faster pace and engage more muscles than are normally used for walking. You may also rely more on your arms to keep your head above water, engaging upper body muscles that normally don't play much a role in dry land walking. Using these additional muscles will increase your heart rate.
At low or moderate intensity, walking in water is more demanding on your cardiovascular system than walking on land. That's because both your arms and legs are facing the increased resistance of water, which is 800 times more dense than air. However, it's difficult for most people walking in water to push themselves as hard as when they are walking at high intensity on dry land, such as when they are climbing a hill.
Tricks For Increasing Difficulty
There are a few ways to make walking in water more difficult when wearing a water float. One way is to concentrate on keeping your head dry; this may force you to maintain a higher level of effort so you don't sink temporarily below the water surface. You can also try walking in warmer water, or wearing a tight synthetic shirt, which will cut down on the amount of heat lost to the water and help elevate your heart rate.
Injury Prevention and Rehabilitation
Running or walking in water is an excellent way to maintain fitness when you have an injury. However, don't do any water walking or jogging if you have a hip flexor injury, which can be aggravated by these kinds of underwater motions. Although water walking may be more strenuous than walking on flat ground, cool water and water pressure aid circulation and prevent your heart rate from climbing as high as it might under some dry land conditions.