Preliminary Studies of Exercise Capacity in Combat Swimmers after Cold Water Training Operations

Abstract

Four special warfare combat swimmers performed exercise before and after open water training exercises in swimmer delivery vehicles. The divers wore standard issue dry suits. The water temperature was 7-9 C. The resting heart rate values were higher in the predive state than in the postdive state. Maximum predive heart rates during a 5 min step test approached 70-90% of the maximum heart rate predicted for age. These high heart rate values were 10-20% higher than values obtained when the exercise was conducted on a nondive day wearing usual exercise gear. Recovery of heart rate after exercise was faster in the postdive state and may be attributed in part to after-drop in rectal temperature. Maximum forearm grip strength decreased approximately 10% in predive and postdive testing conditions.