The Resistance Exercise Training for Worry Trial: Replication and Expansion

Resistance exercise training was designed in accordance with World Health Organization and American College of Sports Medicine guidelines. The eight-week, twice-weekly intervention was designed such that moderate-to-high intensity participants could achieve two sets of 8-12 repetitions of the eight exercises before volitional fatigue, a deterioration in lifting form, or failure to complete a repetition, using loads of approximately 70-80% of their estimated one-repetition maximum. Completed in the following order, the exercises were: barbell back squat, barbell bench press, hexagon bar deadlift, barbell bent over row, dumbbell lunges, seated dumbbell lateral raises, weighted or unweighted abdominal crunches, and seated dumbbell bicep curls. There was one minute of rest between each set, and two minutes of rest between each exercise. If participants could complete two sets of 12 repetitions, load was increased gradually by approximately 5% in the following session.

The low intensity SHAM condition was matched all features of engagement with the moderate-to-high intensity intervention apart from load, and load progression. Low intensity SHAM participants completed the same program with loads of approximately 20% of their estimated one-repetition maximum. To maintain low intensity, repetitions completed on the main, heavier lifts (i.e., back squat, bench press, deadlift, bent over row) were increased from 10 in one session to 12 in the next; load was then increased by approximately 10% in the following session, and 10 reps were performed again. On the remaining lighter, assistance lifts, eight repetitions were performed per set, then one repetition was added to both sets in each session, and load was increased by the smallest increment possible when two sets of 12 repetitions were performed. Borg's 6-20 rating of perceived exertion scores were used to monitor intensity, such that if scores exceeded 11, load and reps were not progressed.