Table 1: Characteristics of studies and samples included in review (N = 19).

Author (year) Country Sex Age (years) Sport type(s) Competitive standard(s) Years of sport experience
[M (SD) or range]
♂ ♀ Group M (SD)
Wieser & Thiel
(2014)*		 GB 20 - 18-33 24.8 (4.63) S INT; NAT seniors 7.7 (4.84)
Drees & Mack
(2012)***		 US 54 - 14-18 15.98 (1.24) WR REG; REC juniors 1 (n = 3); 2-5 (n = 25); 6-10 (n =16); ≥10 (n =10)
Cowden
(2016)†		 ZA 25 18 - 13.6 (2.4) T NAT; REG; REC juniors -
Cowden et al.
(2014)**		 US 8 8 - ♂ = 20.9 (1.4);
♀ = 19.4 (1.2)		 T UN seniors -
Gucciardi et al.
(2009b)†		 AU 418 - 15-30 18.97 (3.71) AF AM; S-EL; EL juniors and seniors 10.33 (3.57)
Weissensteiner et al. (2012)† AU 21 - - NAT/REG = 22.5 (2); CL = 27 (5.8) C NAT; REG; CL seniors NAT/REG = 13.3 (2.8)
CL = 17.2 (6.1)
Kuan & Roy
(2007)†		 MY 21 19 19-27 21.43 (1.66) WU UN seniors 2.66 (1.6)
Crust & Azadi
(2010)†		 GB 67 40 - ♂ = 22.6 (5);
♀ = 21.6 (2.8)		 VS NAT (n = 5); C (n = 66);
CL/UN (n = 36) seniors		 -
Cowden & Meyer-Weitz (2015)† ZA 191 174 - ♂ = 31.32 (15.28);
♀ = 26.03 (11.08)		 T INT (n = 35); NAT (n = 83); UN (n = 160);
LCT (n = 24); C (n = 63) seniors		 INT = 19.06 (16.54); NAT = 20.04 (13.68); UN = 11.32 (4.05); LCT = 18.21 (12.58); CC = 24.37 (14.07)
Nicholls et al.
(2009)†		 GB 454 223 15-58 22.66 (7.2) VS INT (n = 60); NAT (n = 99); C (n = 198);
CL/UN (n = 289); BEG (n = 31) juniors and seniors		 11.65 (7.43)
Mahoney et al.
(2014)†		 AU 136 85 - ♂ = 14.39 (1.44);
♀ = 14.29 (1.53)		 CC AM juniors 4.47 (2.57)
Chen & Cheesman (2013)† US 136 - 18-42 27.2 (4.8) MMA PRO (n = 49); S-PRO (n = 39); AM (n = 48) seniors -
Madrigal et al.
(2013)†		 US 74 69 18-24 19.98 (NS) B UN seniors -
Newland et al.
(2013)†		 US 92 105 - - B UN seniors -
Sheard et al.
(2009)†		 GB 778 364 16-63 (n1 = 633);
18-48 (n2 = 509)		 N1 = 21.5 (5.48);
N2 = 20.2 (3.35)		 VS INT (n = 79); NAT (n = 150); C/PROV (n = 479); CL/REG (n = 434) juniors and seniors -
Meggs et al.
(2014)†		 GB 65 40 18-25 (n = 78); 26-35 (n = 10); ≥36 (n = 17) - VS INT (n = 9); NAT (n = 18); REG (n = 29);
REC (n = 49) seniors		 7.5 (1.33)
Crust
(2009)†		 GB 55 57 - ♂ = 30.1 (11.6);
♀ = 28.6 (8.9)		 VS CL to NAT (n = 63); REC (n = 49) seniors -
Hagag & Ali
(2014)†		 EG 12 10 - - F INT seniors -
Gucciardi et al.
(2016)†		 AU 330 - 15-18 16.86 (.71) AF AM juniors 9.32 (2.51)

Note. GB = United Kingdom, US = United States of America, ZA = South Africa, AU = Australia, MY = Malaysia, EG = Egypt, ♂ = Male, ♀ = Female, n = number of participants, M = Mean, SD = Standard deviation, S = Soccer, WR = Wrestling, T = Tennis, AF = Australian football, C = Cricket, VS = Variety of sports, WU = Wushu, CC = Cross-country running, MMA = Mixed martial arts, B = Basketball, F = Fencing, NAT = National, REG = Regional, CL = Club, C = County, LCT = Local county tournament, UN = University (team/league), INT = International, REC = Recreational (school/leisure), AM = Amateur, S-EL = Sub-elite, EL = Elite, B = Beginner, PRO = Professional, S-PRO = Semi-professional, PROV = Provincial. † = cross-sectional, self-report study design. * = cross-sectional, coach-rated study design (one coach rating per instrument). ** = cross-sectional, coach and athlete-rated study design. *** = Longitudinal, self-report study design.