Table 2.

Summary of chronic feedback studies included in the systematic review

Study	Participants	Feedback type(s)	Outcome measures	Outcomes
Nagata et al. 2020 [19]	Immediate feedback group: 9 Collegiate rugby players Average feedback group: 10 Collegiate rugby players Visual feedback group: 10 Collegiate rugby players Control group: 8 Collegiate rugby players Age: 20.89 ± 0.8	Verbal velocity feedback following each repetition Visual mean velocity feedback following each set Video recording of each repetition	30-kg squat jump velocity	Immediate verbal feedback showed the greatest improvements in squat jump velocity and retainment across a 4-week period
Randell et al. 2011 [20]	Feedback group: 7 Professional rugby players Age: 25.7 ± 3.6 Control group: 6 Professional rugby players Age: 24.2 ± 2.5	Visual velocity feedback following each repetition	Vertical jump, broad jump, 10-m, 20-m, 30-m sprint	Feedback group tended to show superior improvements in physical qualities across a 6-week period
Sakadjian et al. 2014 [49]	Action observation group: 8 State-level Australian Football players	Verbal coaching cues and observation of video demonstration by a skilled model before each set Verbal coaching cues before each set	Power clean peak power output; power clean technique analysis	Action observation group showed superior improvements in power clean peak power output and technique across a 4-week period
Vanderka et al. 2020 [21]	Feedback group: Strength-trained males Age: 22.9 ± 2.2 Control group: Strength-trained males Age: 23 ± 2	Visual power output feedback after each repetition	30- and 50-m sprint; 20-m flying sprint; 3RM back half squat; loaded squat jump power max (W and load); CMJ; squat jump	Feedback group showed superior improvements in physical qualities across a 6-week training period
Weakley et al. 2019 [22]	Feedback group: 16 Semi-professional rugby players Age: 21 ± 1 Control group: 12 Semi-professional rugby players Age: 21 ± 2	Visual and verbal velocity or displacement feedback following each repetition	CMJ; broad jump; 3RM back squat and bench press; 10- and 20-m sprint	Feedback group tended to show superior improvements in physical qualities across a 4-week training period
Winchester et al. 2005 [48]	Feedback group: 18 NCAA Division III athletes Age: 22.22 ± 2.13	Visual feedback with video recording and verbal coaching cues	Power clean peak power output, peak force, and bar-path kinematic variables	Improvements were seen in kinetic and kinematic outcomes across a 4-week period
Winchester et al. 2009 [23]	Feedback group: 12 NCAA Division I football players Control group: 12 NCAA Division I football players Age: 21.72 ± 1.94	Visual feedback with video recording and verbal coaching cues	Power snatch peak power output, peak force, and bar-path kinematic variables at 50%, 70% and 90% 1RM	Feedback group showed superior improvements in kinetic and kinematic outcomes across a 4-week period

1RM one repetition maximum, 3RM three repetition maximum, CMJ countermovement jump, W watts