There is a phenomenon called the “bilateral deficit” which allows you to recruit more muscle and lift more weight with one limb. The common example used to describe the bilateral deficit phenomenon is simple to understand. If an individual can lift 50 pounds during a maximal effort one-arm biceps curl, the same individual probably cannot lift 100 pounds during a maximal effort two-arm biceps curl. Intuitively, the total maximum performance elicited by two limbs working simultaneously should be equal to the sum of the maximum performances elicited by each limb working independently. However, this is usually not true, and the inferiority of simultaneous bilateral exercise performances is termed the bilateral deficit. I know, it goes against common sense, but it’s true. When performing single limb exercises, your body recruits more muscles to help stabilize the weight, resulting in higher force output. So, dumbbell or kettlebell training are perfect ways to take advantage of the bilateral deficit and build bigger, stronger muscles!

Unilateral training is more effective at burning fat than using two-limb versions of the same exercise. Unilateral training is when you first perform all the repetitions with one arm or leg, and then immediately perform the same amount of repetitions with the other arm or leg. Dumbbells or kettlebells are great for this type of traing and can be used in unison, unilaterally, or in an alternating fashion to exercise the entire body. Exercises using dumbbells or kettlebells closely mimic the movements you encounter in your daily life through sport, work or just life activities.