well this can be a result of a number of things. commonly when we exercise we dilate our peripheral capillary beds shunting blood toward the skin to assist with cooling. this capillary dilatation can lead to an itching sensation. no may have some vasodilatory properties and thus be enhancing these feelings. more ominous is exercise-related anaphylaxis in which -- with high intensity exercise -- your body can have a reaction similar to any other allergic reaction. this is not very common but if you experience other symptoms beyond just itching i would seek the advice of a local sports doc.
why do i get an intense tingling/itchy sensation all over my body when i work out? i take no extreme a supplement.