On their own, without the addition of stimulants, nitric oxide supplements provide an extra pump during training for bodybuilders and serious athletes. Nitric oxide performs many functions in the body, including increasing blood flow, improving the levels of oxygen and nutrients sent to the body, including skeletal muscles. For those sensitive to stimulants, stimulant-free nitric oxide will still provide all the benefits of nitric oxide, without the jitters that often accompany regular use of stimulants like caffeine. When training hard, you’ll find your body’s goals closer and easier to achieve by using nitric oxide without any of the side effects of adding a stimulant.