Use a lighter weight than what you would use out of water. Water adds resistance that causes your muscles to work harder to perform the exercise. You should use approximately one-third the weight you would normally use. For example, if you normally lift 30-pound barbells, use 10-pound barbells in the water.
Perform upper-body exercises in water that is shoulder height when standing upright. This provides maximum resistance and fastest results for water fitness.
Execute lower-body exercises in water that is at least waist height. This allows you to perform moves like weighted squats or lunges with maximum resistance.
Start with three sets consisting of 10 repetitions per exercise. According to Lynda Huey and Robert Forster, authors of "The Complete Waterpower Workout Book," this is the ideal number of repetitions when beginning a water weight routine.
Dry your weights with a towel after using them in water. Water can damage the neoprene or rubber coating if left to sit on the material.