When it comes to weight control, the consensus has been that “more exercise is better”. However, there may be at least one exception: swimming. Few studies have specifically measured weight loss through swimming as a preferred exercise. None of them have given swimming high marks.
Perhaps the most comprehensive and carefully conducted study was conducted on minimally to moderately obese young women who were otherwise healthy and were seeking to lose weight through a program of exercise without dietary restrictions. The participants were randomly assigned to one of three groups in which only the type of daily exercise was different. The three types of exercise were brisk walking, riding a stationary cycle, and swimming laps in a pool. All women slowly but progressively increased the time spent in daily exercise to 60 minutes. The conclusions: “After six months or slightly longer, the women assigned to walking lost 10% of their initial weight, the women who cycled lost 12%, but the women who swam lost no weight.” (Am J Sports Med 1987 May-Jun;15(3):275-9 Weight loss without dietary restriction: efficacy of different forms of aerobic exercise.Gwinup G)
Some people would say that the women didn’t lose weight because they were putting on muscle. Unfortunately, however, that doesn’t explain the outcome. This and other studies have measured change in body fat over time. The results of this study showed that both walking and cycling are effective methods of reducing body fat, but that swimming is not. Other studies have evaluated combined exercises and report better results, but all of the weight loss could be accounted for by walking and diet alone (Am J Clin Nutr 1992 Jul;56(1 Suppl):294S-296S Outcome of a multicenter outpatient weight-management program including very-low-calorie diet and exercise. Saris WH, Koenders MC, Pannemans DL, van Baak MA).
The possibility has also been raised that girls who choose swimming as a form of exercise may weigh more and have more body fat than those choosing other activities. In one such study, the height, body composition and prevalence of obesity of 78 female gymnasts was compared to 52 girl swimmers and 116 girls who did neither. The female gymnasts were shorter and lighter than girl swimmers. They were also shorter than the non-exercising girls. The female gymnasts had less body fat and a later biological maturation than the other girls (Growth 1983 Spring;47(1):1-12 Height, body composition, biological maturation and training in relation to socio-economic status in girl gymnasts, swimmers, and controls. Bernink MJ, Erich WB, Peltenburg AL, Zonderland ML, Huisveld IA).
At the Lindora Clinics, we ask ‘Lean for Life’ program participants about the type and amount of exercise they participate in daily. Our sense is that swimming has not produced weight loss results comparable to other exercises.