Understanding the effects of aquatic exercise on human health and physiology

Aquatic versus land-based exercise

Obesity has long been noted as a risk factor for cardiovascular disease, although it is less significant a risk than inactivity. In several studies, swimming and aquatic activity did not seem to produce as significant an effect on weight loss and per cent body fat as land-based activity did. Further, swimming did not seem to produce significant increases in high-density lipoprotein cholesterol (HDL-C) when compared to land-based exercise as has been noted both in young and older swimmers compared to their land-exercising peers.

Other studies, however, have shown when exercise intensity and duration are matched completely, both forms of exercise may be expected to produce both weight loss and an increase in lean body mass. These and other studies have also shown swimming and other aquatic exercises do produce a decrease in total cholesterol and low-density lipoproteins (LDL-C). Aquatic exercise and swimming are useful forms of exercise in obesity, especially because of the off-loading produced by buoyancy. Although an active aquatic exercise program may not produce major weight loss, such programs will produce an increase in overall fitness, muscle strength, balance, and perceived quality of life.

Reducing the risk of developing insulin resistance

Linked with obesity and inactivity is a much higher likelihood of developing insulin resistance, a precursor to diabetes, one of the fastest-growing chronic diseases. The U.S. Centers for Disease Control (CDC) estimates if current trends are not intercepted, within the next four decades, the number of adults with diabetes could double or even triple, increasing the prevalence from the current one in nine adults to three adults out of nine.

Aquatic exercise can be helpful in reducing the risk of developing insulin resistance or decreasing insulin resistance if already present as it lowers fasting insulin levels while raising insulin sensitivity. It has also been shown to reduce the level of hemoglobin (A_1c), a measure of average blood glucose levels over time. These findings can be important reasons to promote aquatics to those at risk of developing diabetes or those who have been diagnosed with it.

Promoting aquatics for better health

While all of the above effects of aquatic exercise and activity seem to be receiving increased recognition within the lay press and medicine, there remains a dramatic underuse of aquatic facilities for health promotion and maintenance.

Unfortunately, many aquatic facilities often lack imaginative programming for adults in need of healthful aquatic activity and physicians are unaware of the many potential health and cost-saving benefits of aquatics. Given the rates of cardiovascular disease, cardiac debility, obesity and diabetes and their many medical complications, the costs of these health issues may eventually become unsustainable. Therefore, the industry must do a better job to increase public and professional awareness to the benefits of aquatic exercise, not only for the betterment of public health, but also for the pool and spa industry.

Bruce E. Becker, MS, an internationally recognized expert in the field of aquatic therapy, is a clinical professor in the Department of Rehabilitation Medicine at the University of Washington, and an adjunct research professor at Washington State University where he directs the National Aquatics & Sports Medicine Institute. He is the editor and co-author of Comprehensive Aquatic Therapy, and has written, researched and lectured extensively in the field of aquatic therapy for more than 30 years. Becker also serves as the director of aquatic health benefit research at the National Swimming Pool Foundation (NSPF) and is a frequent presenter at the World Aquatic Health Conference (WAHC). To view his seminars online, visit www.nspf.org. Becker can be reached via e-mail at aquaticdoc@msn.com.