Table 4

Overall as well as age, sex, sport and training type-specific effects of resistance training in youth athletes

 Muscle strengthVertical jump performanceLinear sprint performanceAgilitySport-specific performance
SMDwmS (I)NSMDwmS (I)NSMDwmS (I)NSMDwmS (I)NSMDwmS (I)N
All1.0916 (23)2780.8033 (47)7020.5822 (34)5270.6814 (25)4100.7520 (27)345
Maturityp=NAp=0.60p=0.58p=0.99p=0.17
 Prepubertal (Tanner Stage I and II)oEG0.913 (5)760.653 (5)760.581 (3)370.271 (3)37
 (Post-) pubertal (tanner stage III–V)0.616 (8)901.1511 (13)2610.514 (6)1690.573 (4)1490.728 (9)135
Chronological agep=0.43p=0.74p=0.92p=0.39p=0.05
 Children (boys ≤13 years, girls≤11 years)1.353 (4)390.7810 (17)2350.559 (14)1950.526 (11)1460.506 (11)153
 Adolescence (boys 14–18 years, girls 12–18 years)0.9113 (17)2110.8522 (28)4390.5713 (18)3020.717 (12)2341.0313 (15)181
Sexp=0.92p=0.54p=NAp=NAp=0.04
 Boys1.2112 (18)2200.8527 (40)6150.6319 (30)4740.7412 (22)3740.7215 (22)288
 GirlsoEG0.613 (3)37oEG1.812 (2)24
Sportp=0.15p=0.20p=NAp=NAp=0.35
 Team sports1.1513 (20)2400.7930 (44)6620.5821 (33)5130.6814 (25)4100.8017 (24)312
 Martial arts
 Strength-dominant sports0.582 (2)241.222 (2)26oEG0.343 (3)33
 Technical/acrobatic sports
Training typep<0.001p=0.41p=0.12p=0.03p=0.02
 Machine based0.363 (3)361.453 (3)380.303 (3)37
 Free weights2.972 (4)720.903 (5)800.613 (5)801.311 (3)62
 Machine based and free weights1.164 (6)540.773 (4)390.182 (3)29oEGoEG
 Functional training0.622 (3)340.392 (3)520.192 (3)520.382 (3)520.795 (5)84
 Complex trainingoEG1.664 (5)561.113 (5)380.662 (3)381.852 (3)25
 Plyometric training0.394 (5)560.8116 (25)4060.6410 (16)3000.627 (13)2490.7410 (15)190
  • N, total number of participants in the included experimental groups; NA, not applicable; oEG, only one experimental group; S (I), number of included studies (number of included experimental groups); SMDwm, weighted mean standardised mean difference; y, years.