Not long ago, trainers inserted balance training into their strength and musclebuilding workouts. This was great if you were an athlete who performed in a highly unstable activity, but highly counterproductive if you were trying to maximize muscle or strength gains. Oftentimes, exercise balls or balance boards were the instruments used to provide a more unstable environment from which an exercise was done.
While balance is an important skill in terms of general fitness, including it in your training when you’re focused on optimizing muscle or strength comes at a cost: you have to sacrifice so much in terms of load that you’ll never be handle anywhere near your maximal loads.1,2 Go ahead, try a dumbbell bench press on a flat bench with your 8RM and the same movement with the same weight on an exercise ball.
If you’re training for maximal size or strength, stick with basic movements with your feet on the ground or your body supported, so that you can go heavy. Any benefits that might accrue in terms of balance aren’t worth the decrease in the load that you’ll be able to handle. If you want to work on your balance, do it separately from your strength workouts.
Not everyone trains for just size and strength, though. In fact, athletes often find themselves in an unstable environment on the field or court. For them, training on unstable surfaces could theoretically complement traditional strength training methods.
1Wahl, M.J., & Behm, D.G., 2008. Not all instability training devices enhance muscle activation in highly resistance-trained individuals. J. Strength Cond. Res. 22(4):1360-1370.
2Behm, D.G., & Anderson, K.G, 2006. The role of instability with resistance training. J. Strength Cond. Res. 20(3):716-722.