The intensity in which effort is expended is essential to the elaboration and control of any exercise program. Whether an activity is performed on land or in water makes a whole difference, because aspects such as volume of immersed body, body position and water temperature result in body conditions different from those seen on land exercise and, thus, influence indicators of the intensity of effort. Considering that heart rate and perceived effort are the most frequently used indicators for the control of the intensity of effort in water exercises, the present review aims at analyzing the main changes that take place in those variables in immersion, comparing to land conditions, as well as the implications of these changes in the prescription of exercise. Therefore, the main changes resulting from situations of rest and exercise, in running and water biking, in water gym and swimming are described herein. Finally, some light is shed on the implications of these changes in the prescription of exercise, as well as on some strategies for the use of these variables in exercise performed in water. In relation to heart rate, one can conclude that occurs a reduction in heart beats during immersion, influenced by water temperature, immersion depth, absence or presence of effort, type and intensity of the exercise. Such reduction should be considered when using this indicator of intensity of effort in water. In relation to perceived exertion, Borg´s scale seems to be a suitable option to control water exercises intensity, being considered its application recommendations.
Heart rate; Perceived exertion; Immersion; Exercise
