One of the most common practices that I see as a trainer is the tendency of many clients to hold on to the handrails while they are doing high intensity interval training on the treadmill.

If you are one of these clients, there may be a couple of reasons why you are doing so. First, you may think that by increasing the intensity to the point where you have to hang on to the rails you will burn more calories. This is not true. By holding on to the handrails, you are eliminating movement in half your body which means you are burning far fewer calories than you think. Also, it forces you to hunch over, an inefficient walking/running form that can lead to neck, shoulder, and back injury. If you lower the incline and/or speed and let go of the rails, walking with your arms pumping naturally by your side, you will burn more calories than ever before.

Another reason why you might hold on is for perceived safety. Remember that you don’t lose your balance walking/jogging naturally outside, so you should not need to use the handrails inside. Start by figuring out your natural walking pace and gradually increase your speed and incline. Your body will adjust and become stronger and more stable. 

Bottom line: If you can let go of the handrails, you will burn more calories, increase your balance, and see a leaner and better-toned version of yourself.