The foam rolling routine consisted in unilateral exercises alternatively performed on both legs and bilateral exercises on lower and back muscles. All participants started with the feet in a standing up position with a lacrosse ball. Then, participants performed on the ground the foam rolling exercises with the foam roller targeting leg and back muscles.

Participants in the manual massage group received manual massage by a professional physiotherapist who was blinded to the purpose of the experiment (20 years of registered practice). Participants were lying in the prone position on a massage table. To facilitate the physiotherapist's maneuvers, massage oil was used. The manual massage protocol reproduced several features of the foam rolling intervention, i.e., order of the areas massaged, massage time per muscles and total duration of the session.

Participants in the relaxation group listened to a 16 min relaxation audio tape, based on the autogenic training method. Participants were lying on the massage table in supine position, wearing headphones. During this desensitization-relaxation technique, they were guided to visualize bodily perceptions of heaviness and warmth in their arms, thorax and legs. To facilitate concentration, participants were left alone in a dark room.

Self-report of perceived anxiety and physical sensations (muscle pain, relaxation and warmth)

Lower back and hamstring flexibility index from sit-and-reach and toe touch tests

Power of alpha and beta neural oscillations

Perceived anxiety and physical sensations (muscle pain, warmth and relaxation) on a numeric rating scale of 10 cm (0: "Complete absence of anxiety/muscle pain/muscle warmth/muscle relaxation"; 10: "Maximal possible levels of anxiety/muscle pain/muscle warmth/muscle relaxation")

Iterated substractions for 2 minutes

Skin conductance during resting state periods