2. Details of measurement of muscle soreness in the included trials.
| Study ID | Outcome measure | Score (higher = worse) | Timing post‐exercise | Data extraction |
| Arent 2010 | Muscle soreness during a squat | VAS (0 to 10 cm) | 24, 48 hours | Text (SDs from SEs) |
| Avery 2003 | Muscle soreness during shoulder abduction, shoulder horizontal adduction and hip flexion (unloaded squat) | VAS (0 to 10 cm) | 24, 48, 72 hours | Text |
| Bailey 2011 | General soreness at the quadriceps | VAS (1 to 10 cm) | 24, 48 hours | Text |
| Beaton 2002a | General soreness at the quadriceps | VAS (0 to 10 cm) | 48 hours | Text |
| Bell 2015 | Muscle soreness during a squat | VAS (0 to 200 mm) | 24, 48, 72 hours | Raw data provided by the authors |
| Bell 2016 | Muscle soreness during a squat | VAS (0 to 200 mm) | 24, 48, 72 hours | Raw data provided by the authors |
| Bloomer 2004 | Active movement of elbow flexion or extension, as well as following light palpitation by the investigators | VAS (0 to 10 cm) | 0, 2, 6, 24, 48, 72, 96 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Bloomer 2005 | Dominant leg during knee extension | VAS (0 to 10 cm) | 0, 10, 24, 48, 72, 96 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Bloomer 2007 | Performance of 2 (concentric‐eccentric) repetitions of the barbell bench press exercise using a standard 20 kg barbell | VAS (0 to 10 cm) | 0, 24, 48 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Bryer 2006 | Delayed onset muscle soreness was assessed in a rested position and in response to palpation on the muscle of the arms | VAS (1 to 10 cm) | 0, 4, 24, 48, 72, 96 hours | Text (SDs from SEs) Immediate pain data used for the up to 6 hours analysis |
| Close 2006 | Delayed onset muscle soreness was measured at the gastrocnemius, anterior tibialis, hamstrings, quadriceps, gluteals (both sides) and lower back muscles | VAS (0 to 10 cm) | 0, 24, 48, 72, 96, 168, 336 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Cobley 2011 | Total muscle soreness after performing a 90 degree squat | VAS (0 to 12 cm) | 0, 24, 48, 50, 72, 96, 98 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Connolly 2006 | General delayed onset muscle soreness assessed at the quadriceps | VAS (0 to 10 cm) | 24, 48, 72, 96 hours | Text |
| Connolly 2006a | Pain scores were obtained by asking participants to verbally rate their overall discomfort during active elbow flexion and extension | VAS (0 to 10 cm) | 24, 48, 72, 96 hours | Text (SDs from SEs) |
| Drobnic 2014 | Muscle soreness during descending and climbing stairs. The following 8 sites were measured: anterior right thigh, posterior right thigh, anterior right leg, posterior right leg, anterior left thigh, posterior left thigh, anterior left leg, posterior left leg and added together for a total score. | VAS (0 to 4) | 48 hours | Raw data provided by the authors |
| Goldfarb 2011 | Delayed onset muscle soreness was measured at the elbow flexor with the arm rested | VAS (1 to 10 cm) | 0, 2, 6, 24, 48, 72 hours | Text (SDs from SEs) Immediate pain data used for the up to 6 hours analysis |
| He 2015 | Delayed onset muscle soreness of the quadriceps, hamstrings, gluteus, gastrocnemius and tibialis anterior | VAS (0 to 6) | 0, 24, 48, 72 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Herrlinger 2015 | Soreness was assessed in a variety of muscle groups including the gastrocnemius, hamstrings, quadriceps, gluteus maximus, lower back, abdominals and the whole body | Likert (0 to 7) | 24, 48, 72, 96 hours | The authors of Herrlinger 2015 were contacted on 2 February 2017 and again on 18February 2017 for missing data as these were not available in the manuscript and could not be extracted from graphs. No response was received and this study was therefore included in the qualitative analysis but not the quantitative analysis. |
| Howatson 2009 | Squat down to 90 degrees (internal joint angle) rise to the start position | VAS (0 to 200 mm) | 0, 24, 48 hours | Text Immediate pain data used for the up to 6 hours analysis |
| Hutchinson 2016 | Full range squat with no external weight | VAS (0 to 10 cm) | 24, 48, 72 hours | Text (SDs from SEs) |
| Kaminski 1992 | General delayed onset muscle soreness was monitored by self‐reporting | VAS (1 to 10 cm) | 0, 10, 24, 48, 58, 72, 96 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Kerksick 2009 | Delayed onset muscle soreness was assessed at the quadriceps | VAS (0 to 10 cm) | 6, 24, 48 hours | Raw data provided by the authors 6 hours post‐exercise data used for the up to 6 hours analysis |
| Krotkiewski 1994 | General soreness | VAS (0 to 10 cm) | 24, 48, 72, 96, 120 hours | Text (SDs from SEs) |
| Kuehl 2010 | General soreness in the legs | VAS (0 to 100 mm) | 0 hours | Text Immediate pain data used for the up to 6 hours analysis |
| Laupheimer 2014 | General soreness in both legs | VAS (0 to 10 cm) | 24 hours | Raw data provided by the authors |
| Lynn 2015 | Squat to a 90 angle and returning to a standing position | VAS (0 to 200 mm) | 0, 24, 48 hours | Text Immediate pain data used for the up to 6 hours analysis |
| McBride 1997 | General soreness | VAS (0 to 10 cm) | 24, 48 hours | Text (SDs from SEs) |
| McCormick 2016 | Upper body, upper legs, lower legs and overall body | VAS (0 to 10 cm) | 24, 48, 72, 96, 120, 144 hours | This study was only included in the qualitative analysis because the exercise paradigm was completely different to all the other studies included in this review |
| McFarlin 2016 | Muscle soreness measured using a gauge. Pressure was applied using standard force (20 to 30 N) over the distal, middle and proximal thigh in a seated position with the knee fully extended and relaxed. The 3 ratings for each quadricep were added together. | VAS (0 to 10 cm) | 24, 48, 72, 96 hours | Text (SDs from SEs) |
| McLeay 2012 | Step up (concentric muscle action) onto a 40 cm box then step down (eccentric muscular contraction) and the soreness was rated | VAS (0 to 10 cm) | 24, 48, 72 hours | Text |
| Meamarbashi 2011 | Participants were requested to rate the general discomfort in only the quadriceps and calf regions of the right leg | VAS (0 to 6) | 0, 24, 48 hours | Text Immediate pain data used for the up to 6 hours analysis |
| Michailidis 2013 | Palpation of the muscle belly and the distal region of the vastus medialis, vastus lateralis and rectus femoris after a squat | VAS (1 to 10 cm) | 0, 2, 24, 48, 72, 96, 120, 144, 168 hours | Text Immediate pain data used for the up to 6 hours analysis |
| Nicol 2015 | Pain was rated for single leg squat, walking downstairs, passive strength of the gluteals and single leg vertical jump | VAS (0 to 10 cm) | 0, 24, 48 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Nie 2004 | Perceived soreness was done during quadriceps extension | VAS (0 to 10 cm) | 0, 24, 48 hours | Text Immediate pain data used for the up to 6 hours analysis |
| O'Connor 2013 | Delayed onset muscle soreness in the arm was rated in response to isometric strength measurement | VAS (0 to 100 mm) | 24, 48 hours | Text |
| O'Fallon 2012 | Delayed onset muscle soreness at the elbow flexor | VAS (0 to 100 mm) | 24, 48, 72, 96, 120 hours | Raw data provided by the authors |
| Peschek 2014 | Delayed onset muscle soreness at the legs | VAS (0 to 10 cm) | 24, 48 hours | Text |
| Phillips 2003 | Soreness measures were subjectively evaluated through palpitation for oedema at he elbow | VAS (0 to 10 cm) | 72, 168 hours | Text (SDs from SEs) |
| Shafat 2004 | Delayed onset muscle soreness was evaluated using a questionnaire employing a visual analogue scale for a total of 8 sites (6 sites on the anterior muscle of the upper leg and 2 sites on the posterior muscles of the upper leg). The participants were asked to palpate the relaxed muscle and rate soreness. | VAS (1 to 10 cm) (x 8): 8 to 80 score |
24, 48 hours | Text |
| Silva 2008 | Delayed onset muscle soreness at the elbow flexor | VAS (0 to 10 cm) | 48, 96, 168 hours | Text |
| Silva 2010 | Muscle soreness of the biceps muscle was assessed | VAS (0 to 10 cm) | 48, 96, 168 hours | Text (SDs from SEs) |
| Su 2008 | At the beginning of the exercise test, participants were instructed to give CR‐10 values | Borg CR (0‐10) | 0, 24, 48 hours | Text (SDs from SEs) Immediate pain data used for the up to 6 hours analysis |
| Tanabe 2015 | Palpitation of the upper arm and passively extending the elbow joint | VAS (0 to 100 mm) | 0, 24. 48, 72, 96 hours | Raw data provided by the authors Immediate pain data used for the up to 6 hours analysis |
| Theodorou 2011 | Squat using body weight | VAS (0 to 10 cm) | 24, 48, 72, 96, 120 hours | Text |
| Thompson 2001 | Actively contracted the quadriceps | VAS (1 to 10 cm) | 24, 48, 72 hours | Text (SDs from SEs); there are no decimal places; where SE = 0, we have put this as 0.4 (SD = 1.2) |
| Thompson 2001a | Actively contracted the quadriceps | VAS (0 to 100 mm) | 24, 48, 72 hours | Text (SDs from SEs) |
| Thompson 2003 | Actively contracted the quadriceps | VAS (1 to 10 cm) | 24, 48, 72 hours | Text (SDs from SEs); there are no decimal places; where SE = 0, we have put this as 0.4 (SD = 1.1313) |
| Thompson 2004 | Actively contracting the leg extensors against resistance equivalent to 75% of each individual's 1 repetition maximum | VAS (0 to 10 cm) | 24, 48, 72 hours | Raw data provided by the authors |
| Trombold 2010 | Unloaded elbow flexion of the tested arm | VAS (0 to 10 cm) | 2, 24, 48, 72, 96 hours | Raw data provided by the authors 2 hours post‐exercise data used for the up to 6 hours analysis |
| Trombold 2011 | Unloaded elbow flexion and knee extension on the tested arm and leg | VAS (0 to 10 cm) | 2, 24, 48, 72, 96 hours | Raw data provided by the authors 2 hours post‐exercise data used for the up to 6 hours analysis |
SD: standard deviation SE: standard error VAS: visual analogue scale