Table 3. Intervention characteristics of the selected studies.

Study	Design	Type of exercise test	Supplementation	Diet control	Measurement Time-points	Performance markers	Muscle damage markers	Inflammatory & oxidative stress markers
Arent et al., 2010	Blinded, placebo-controlled	Graded maximal treadmill test to exhaustion	Resurgex Plus® vs Isocaloric placebo	3-day dietary recall, prior to trials	Before & after treadmill test, at the beginning & end of preseason	Lactate threshold, VO2max, time to exhaustion	CK	8-isoprostane, lipid hydroperoxide
Betts et al., 2009	Single-blind, repeated measures crossover	90min of high-intensity intermittent shuttle-running	CHO vs CHO+PRO	2-day dietary recall, prior to trials & 1-day dietary recall post exercise	At baseline and 4h, 24h, 48h & 168h after exercise	Peak isometric torque-flexors & extensors	Myoglobin, CK, LDH, cortisol	IL-6, IL10, IL-1 receptor antagonist, CRP, WBC
Cockburn et al., 2013	Blinded, repeated measures parallel	Unilateral knee flexions (6 sets x 10 reps, 1.05 rad/s-1, 90-s rest) on isokinetic dynamometer	Semi-skimmed milk vs water	Diet recorded throughout the study	At baseline and 24h, 48h and 72h post-exercise	CMV jump height, reactive strength index, 15-m sprint, agility, LIST	Passive & active DOMS, CK, myoglobin	N/A
Gentle et al., 2014	Randomized cross-over	87-min basketball game stimulation	CHO meal vs CHO+PRO meal	Diet recorded 24 hours prior to the first trial	At baseline, during as well as 30 min and 24h post-exercise	Free throw success, sprint time, jump height	Passive & active DOMS, CK	N/A
Gilson et al., 2010	Double-blind, randomized cross-over	4-day soccer training period, with increased training duration	CHO vs Low-fat chocolate milk	Diet recorded during the 4-day training period	At baseline, day 2 and day 4 post-ITD training period	MVC, T-drill test, vertical jump	Muscle soreness, CK, myoglobin,	N/A
Gunnarsson et al., 2013	Two-group repeated measures	A competitive soccer match	Normal diet vs high carbohydrate-high protein diet	Recorded over 48h post-match	At baseline and 15 min, 24h and 48h after the match	N/A	CK, myoglobin, muscle glycogen resynthesis	N/A
Highton et al., 2013	Double-blind, randomized cross-over	Modified LIST	CHO vs CHO+PRO	2-day dietary recall, prior to trials	At baseline, during and immediately after LIST	Distance covered, maximal speed & average running speed during LIST	N/A	N/A
Naclerio et al., 2014	Double-blind, single group repeated measures	90-min intermittent repeated sprint test	PLA vs CHO vs CHO+PRO multi-ingredient	3-day dietary recall, prior to trials	At baseline, immediately post, 1h and 24h post-exercise	Total sprint time, 15-m sprint time	CK, myoglobin	IL-6
Naclerio et al., 2015	Double-blind, repeated measures, counter-balanced, crossover	90-min intermittent repeated sprint (IRS) test	PLA vs CHO vs CHO+PRO multi-ingredient	3-day dietary recall, prior to trials	At baseline, immediately post, 1h and 24h post-exercise	Time for 90-min IRS, 15-m sprint test	Myoglobin, CK,	IL-6, Neutrophil, Lymphocytes, Monocyte
Poulios et al., 2018	Randomized, repeated-measures, crossover, double-blind	Two-trial (2 weeks), 2 soccer matches & 4 practices /week	Milk Protein Smooth (PRO) vs isoenergetic placebo (maltodextrin)	Diet recorded Prior to each trial (RMR, REE) 7-day dietary recall during both trials	At baseline, immediately post, 24h, 48h, 72h post -1st match, 24h, 48h, 72h post-2nd match for blood, At baseline 24h, 48h post -1st match, 24h, 48h, 72h post-2nd match for performance testing	10-m sprint(s), 30-m sprint (s), CMJ (cm), KE strength, KF strength GPS: Average HR, Total distance, Distance at >14 km/h, Peak speed (km/h), Accelerations, Decelerations	CK, DOMS	WBC, Granulocyte, TBARS, PC, GSH, TAC

CK: Creatine kinase, LDH: Lactate dehydrogenase, CHO: Carbohydrate, PRO: Protein, DOMS: Delayed onset of muscle soreness, LIST: Loughborough Intermittent Shuttle Test, HR: Heart rate, RPE: Ratings of perceived exertion, MVC: Maximal voluntary contraction, PLA: Placebo, RMR: Resting Metabolic Rate, TDEE: Total Daily Energy Expenditure, KE: Knee extensors, KF: Knee Flexors, WBC: White blood, cells, GSH: Reduced glutathione, TBARS: Thiobarbituric acid reactive substances, PC: Protein carbonyls, TAC: Total antioxidant capacity, GPS: global positioning system.