BACKGROUND: The aim of the present study was to compare differences in electromyography (EMG) activation of the neck and shoulder muscles between groups of inexperienced and experienced pilots during controlled +G_z exposure in a centrifuge. METHODS: The subjects were volunteer cadets (inexperienced group) and lieutenants (experienced group) undergoing their first centrifuge training. The first group did not have any high performance aircraft (HPA) experience, while the latter one had a 1-yr experience of intense flying of HPA. During the centrifuge run, EMG activity was recorded from the left and right shoulder, neck flexor, and neck extensor muscles. RESULTS: The pilots without HPA experience had significantly higher muscle activity in the neck flexor and extensor muscles during the last 5 s of the recorded period at G levels exceeding +7.4. DISCUSSION: Muscle activity in the neck and shoulder muscles was gradually higher among the whole study group with increasing +G_z forces. Because pilots without any HPA experience had significantly higher muscle activity than their counterparts with experience of HPA, we suppose that the experience of high +G_z forces might lead to lower muscle activation in the same flight mission. Honkanen T, Oksa J, Mäntysaari MJ, Kyröläinen H, Avela J. Neck and Shoulder Muscle Activation Among Experienced and Inexperienced Pilots in +G_z Exposure. Aerosp Med Hum Perform. 2017; 88(2):90–95.