Skip to main content

Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Table 1 Physiological and functional adaptations to strength training

From: Strength training in soccer with a specific focus on highly trained players

Study Level/country/ n (age) Type of training F/D P Physiological adaptations Performance changes
Bogdanis et al., [2] Professional/Greek/9 (22.9 ± 1.1) RST: Program 1 - 8 to 12 upper and lower body exercises + 4 sets of half-squats at 90% 1RM/5 rep/3-min rest between sets/emphasis on maximal mobilization during concentric action 3×/wk/6 wks PS ↑17.3% 1RM† ↑16.3% 1RM/LLV† ↑6.2% PPO† ↑5.7% F0 (kg) ↔ Vopt (ver.min−1); V0 (ver.min−1); LLV ↑ ~1.6% 10m sprint † ↑ ~1.9% 40-m sprint ↑ ~2.5% 10 × 10-m Zig-Zag test (45° COD)† ↑ ~2.1% t-test† ↑ ~1% Illinois† ↑ ~10% CMJ†
   RST: Program 2 - 8 to 12 upper and lower body exercise + 4 sets of half-squat at 70% 1RM/12 rep/1.5-min rest/emphasis on both eccentric and concentric action with controlled movement speed    ↑ 4.2% LLV ↑ 11% 1RM ↑ 6.6% 1RM/LLV ↑4.1% PPO ↔ Vopt (ver.min−1); V0 (ver.min−1); F0 (kg) ↑ ~1% 10-m sprint
↑ ~1.9% 40-m sprint ↑ ~1.3% 10 × 10-m Zig-Zag test (45° COD) ↑ ~1.2% t-test ↑ ~0.6% Illinois ↑ ~5.3% CMJ
Bogdanis et al., [3] Professional/Greek/9 (22.9 ± 1.1) The Program 1 adopted in the previous study 3×/wk/6 wks PS ↑ 5.4% total work in RSA ↑ 10.9% RE ↑ 4.9% VO2 max ↑ 7% MAS ↑ 29.4% YYIE2 ↑ 10% DTT
   The Program 2 adopted in the previous study    ↑ 4.5% total work in RSA ↑ 6.2% VO2 max ↑ 5.8% VO2 max ↔ RE ↑ 21.5% YYIE2 ↑ 9.6% DTT
Loturco et al. [22] Professional/Brazil/16 (19.8 ± 0.72) RST (wk1 to wk3): half-squat exercise during first 3 weeks: wk1 - 4 sets × 8 rep (50% 1RM); wk2 - 4 sets × 8 rep (65% 1RM); wk3 - 4 sets × 8 rep (80% 1RM)
Power training (wk4 to wk6): jump squat exercise: wk4 - 4 sets × 4 rep (60% 1RM); wk5 - 4 sets × 5 rep (45% 1RM); wk6 - 4 sets × 6 rep (30% 1RM)
2×/wk/6 wks PS ↑ 19.8% 1RM ↑ 18.5% MP60%-1RM-squat ↑ 29.1% MPP45%-1RM-jump squat ↑ 4.3% 10m sprint ↑ 7.1% SJ ↑ 6.7% CMJ ↔ 30-m sprint
  Professional/Brazil/9 (19.1 ± 0.7) RST (wk1 to wk3): half-squat exercise during first 3 weeks: wk1 - 4 sets × 8 rep (50% 1RM); wk2 - 4 sets × 8 rep (65% 1RM); wk3 - 4 sets × 8 rep (80% 1RM)
Power training (wk4 to wk6): jump squat exercise: wk4 - 4 sets × 6 rep (30% 1RM); wk5 - 5 sets × 5 rep (45% 1RM); wk6 - 4 sets × 4 rep (60% 1RM)
2×/wk/6 wks PS ↑ 22.1% 1RM ↑ 20.4% MP60%-1RM-squat ↑ 31% MPP45%-1RM-jump squat ↑ 1.6% 10m sprint ↑ 4.5% SJ ↑ 6.9% CMJ ↔ 30-m sprint
Ronnestad et al., [6] Professional/Norway/6 (22 ± 2.5) RST (half-squats): wk1 to 2 (3 sets × 6RM); wk3 to 5 (4 sets × 5RM); wk6 to 7 (5 sets × 4RM) emphasizing maximal mobilization in concentric phase and slower eccentric phase (i.e. ~2 s). 2×/wk/7 wks PS ↑ 26% 1RM ↑ 9.9% PPO20kg ↑ 11.1% PPO50kg ↔ PPO35kg ↑3.6% 4BT ↔ CMJ, SJ; 10m sprint; 30-40m sprint; 40m sprint time
  8 (23 ± 2) RST plus PT performed in the same session: ALB = [wk1 to 2 (3 sets × 8 rep); wk3 (3 sets × 8 rep); wk4 to 5 (3 sets × 10 rep); wk6 to 7 (4 sets × 10 rep)]/DLHJ = [wk1 to 7 (2 sets × 5 rep)]/SLFH = [wk1 to 7 (2 sets × 5 rep)] maximal intensity, emphasizing fast switch from eccentric to concentric contraction; 1-min rest between sets 2×/wk/7 wks   ↑ 23% 1RM ↑ 10% PPO20kg ↑ 8% PPO35kg ↑ 9.5% PPO50kg ↑ 4% 4BT ↑ 9.1% SJ ↑ 0.009% 30- to 40-m sprint time ↑ 1.1% 40-m sprint ↔ CMJ; 10-m sprint
Koundourakis et al., [48] Professional/Greece/1st league 23 (25.5 ± 1.1) Team A (high-strength training stress): PS: 11 sessions RST + 15 sessions. SST + 4 sessions SAQ during 7 weeks pre-season; IN: 1 sessions RST; 2 sessions SST; 2 sessions SAQ; 1 sessions speed and 1 session reaction speed training during each week of in-season training RST: circuit strength training, 10 stations, 4 sets, 10 reps in free weights, 4-min rest between sets; 70% to 80% 1RM; 2 core strength exercises + lunge, squats, steps up on bench with external weight, pullover, arm curls, triceps, and bench press PS: 7 wks IN: 35 wks PS + IN IN1: ↑ 5.3% VO2 max ↑ 16.6% BF IN2: ↑ 26.4% BF ↔ VO2 max IN1: ↑ 7.7% SJ ↑ 7.2% CMJ ↑ 2.2% 10-m sprint ↑ 1% 20-m sprint IN2: ↑ 3.8% SJ ↑ 4% CMJ ↑ 1.1%10-m sprint ↑ 0.3% 20-m sprint
  Professional/Greece/1st league 22 (24.7 ± 1.0) Team B (moderate-strength training stress): PS: 6 sessions RST + 9 sessions SST + 4 sessions. SAQ during 7 weeks pre-season IN: 1 session RST/wk; 1 session SST; 1 session SAQ; 1 session speed training during each week of in-season training RST: 4 sets; 6 reps, 90% 1RM; explosive action high execution speed; leg extension, hamstring curls chest press, calf raise, pullover arm curls and biceps PS: 7 wks IN: 35 wks PS + IN IN 1: ↑ 3.9% VO2 max ↑ 16.7% BF IN2: ↔ VO2 max; % BF IN1: ↑ 8.1% SJ ↑ 7.7% CMJ ↑ 2.8% 10-m sprint ↑ 1.6% 20-m sprint IN2: ↔ SJ; CMJ; 10- and 20-m sprint
  Professional/Greece/2nd league 22 (23.8 ± 0.9) Team C (low-strength training stress) PS: 4 session RST + 7 session SST + 4 session SAQ performed during 7 weeks pre-season IN: 1 session RST or SST; 1 session SAQ; 1 session speed training during each week of in-season training RST: 4 sets; 6 reps, 90% 1RM; explosive action high execution speed, (alternating with SST training every second strength training session); leg extension, hamstring curls chest press, calf raise, pullover arm curls and biceps PS: 7 wks IN: 35 wks PS + IN IN1: ↑ 4% VO2 max ↑ 8.7% BF IN2: ↔ VO2 max; % BF IN1: ↑ 5.9% SJ ↑ 4.8% CMJ ↑ 1.7% 10-m sprint ↑ 0.7% 20-m sprint IN2: ↔ SJ; CMJ; 10m and 20-m sprint
Ronnestad et al., [1] Professional/Norway/ 7 (22 ± 2) RST - PS: wk1 to 3 (1st session - 3 × 10RM + 2nd session - 3 × 6RM); wk4 to 6 (1st session - 3 × 8RM + 2nd session - 3 × 5RM); wk7 to 10 (1st session - 3 × 6RM + 2nd session - 3 × 4RM); IN: wk11 to 22 (1 session wk - 3 × 4RM) half-squats emphasizing maximal mobilization in concentric phase and slower eccentric phase 2×/wk/10 wks + 1×/wk/12 wks PS + IN PS: ↑ 19% 1RM IN: ↔ 1RM PS: ↑ 1.8% 40-m sprint ↑ 3.3% SJ ↔ CMJ; IN: ↔ 40-m sprint; SJ; CMJ
  Professional/Norway/7 (26 ± 2) RST - PS: wk1 to 3 (1st session - 3 × 10RM + 2nd session - 3 × 6RM); wk4 to 6 (1st session - 3 × 8RM + 2nd session - 3 × 5RM); wk7 to 10 (1st session - 3 × 6RM + 2nd session - 3 × 4RM); IN: wk11 to 22 (1 session each 2 wk - 3 × 4RM) half-squats emphasizing maximal mobilization in concentric phase and slower eccentric phase 2×/wk/10 wks + 0.5×/wk/12 wks PS + IN PS: ↑ 19% 1RM IN: ↓ 10% 1RM PS: ↑ 1.8% 40-m sprint ↑ 3.3% SJ ↔ CMJ; IN: ↓ 1.1% 40-m sprint ↔ SJ; CMJ
Chelly et al.,[14] Junior/NS/11 (17.3 ± 0.5) RST - back half-squat 1st - 1 set × 7 rep 70% 1RM 2nd - 1 set × 4 rep 80% 1RM 3rd - 1 set × 3 rep at 85% 1RM 4th - 1 set × 2 rep 90% 1RM 2×/wk/8 wks IS ↑ 25% 1RM ↑ 7.2% Wpeak ↔ LMV; TMV, MTCSA ↑ 23% Vfirst step ↑ 7.1% Vfirst 5-m ↑ 12% Vmax ↑ 4.7% 5J ↑ 10% SJ ↔ CMJ; MPV
Kotzamanidis et al., [10] NS/Greece/12 (17.0 ± 1.1) RST plus SP 10-min after strength session: 3 exercises [(Back half-squat at 90° (BHS); step up on a bench with one leg (SU); leg curls for hamstrings (LCH)] wk1 to 4 = 4 sets × 8RM + 4 × 30-m; wk5 to 8 = 4 sets × 6RM + 5 × 30 m; wk9 = 4 sets × 3RM + 6 × 30-m; 3-min rest between sets/3-min rest between sprint rep/10-min interval between strength and sprint program 2×/wk/9 wks ND ↑ 8.6% 1RM of BHS ↑ 17.5% 1RM of SU ↑ 18% 1RM of LCH ↑ 7.8% SJ† ↑ 6.6% CMJ† ↑ 3.5% 30-m sprint† ↔ DJ40cm
  11 (17.1 ± 1.1) Only perform the previous defined RST program 2×/wk/9 wks   ↑ 10% 1RM of BHS ↑ 16.7% 1RM of SU ↑ 16.1% 1RM of LCH ↔ SJ†; CMJ†; DJ40cm; 30-m sprint†
Los Arcos et al., [23] Professional/Spain/11 (20.3 ± 1.9) RST plus vertical-oriented exercises (VS): RST (1 to 2 exercises session) - double (70% to 76% PPO) and single leg (30% to 35% PPO) half-squats (2 sets × 5 reps) and calf exercises (50% to 60% PPO; 2 sets × 5 reps); VS (1 to 2 exercises session) - double and single leg CMJ to box (1 to 3 sets × 3 to 5 reps); vertical jump with load (5% BM; 3 sets × 4 reps); skipping and vertical jump (3 sets × 3 reps); drop vertical jump single leg (2 to 3 sets × 3 reps) 12 sessions/5 wks + 3 wks PS + IS ↑ 12.6% PPO (kg) ↑ 8.1% IT (km.h−1) ↔ 5- and 15-m sprint; CMJ; CMJ D; CMJ ND
  Professional/Spain/11 (19.6 ± 1.9) RST plus vertical and horizontal oriented exercises (VHS): RST: same protocol; VHS (1 to 2 exercises session) - sled walking (5 sets × 1 reps × 10 m; 50% to 55% BM); hip extension wall drill single and double (2 sets × 5 reps); horizontal jump with load (3 sets × 3 to 4 reps; 5% BM); drop horizontal jump single leg (2 to 3 sets × 3 reps); sled-towing (maximal speed, 7.5%; 10 m); double-triple jump (1 × 5 reps) 12 sessions/5 wks + 3 wks PS + IS ↑ 12.2% PPO (kg) ↑ 3.4% IAT (km.h−1) ↑ 3.3% CMJ†; ↔ 5- and 15-m sprint; CMJ D; CMJ ND
Aagaard et al., [4] Elite/Denmark/24 (NS) High-resistance isokinetic strength training 4 sets × 8RM 32 sessions/12 wks OS ↑ 10% to 26% CON IKE(0. 4.18 and 5.24 rad/s) ↑ 9% to 14% CON IKE50° (0 and 0.52 rad/s) ↑ 5% to 29% PPO↑ 3.14 rad/s ↑ 5% to 29% PPO50°(↑ 3.14 rad/s) ↑ 24% to 42% CON IKEVpeak(↑ 5.24 rad/s) ↑ 18% to 32% PPOVpeak (↑ 5.24 rad/s) ↑ MIVC KE (50°) ↔ BS without run up
   Low-resistance isokinetic strength training in isokinetic mode (low-intensity high speed contraction group)4 sets × 24RM    ↑ 9% CON IKE(2.09 rad/s) ↔ PPO; PPO50°; MIVC50°knee extension; CON IKEat Vpeak; PPOVpeak ↑ 5.24 rad/s ↔ BS without run up
   Functional strength training in the form of loaded kicking movements without ball 4 sets × 16RM    ↑ 7% to 13% CON IKE (0.52-2.09-3.14 rad/s) ↑ 9-14% CON IKE50° (0 and 0.52 rad/s) ↑ 7% PPO (4.18 rad/s) ↑ 9-12% PPO50° (0.52-2.09 to 3.14 rad/s) ↔ CON IKE Vpeak; PPOVpeak(↑ 5.24rad/s) ↔ BS without run up
Maio Alves et al., [19] Elite/Portugal/9 (17.4 ± 0.6) CT: 1st station: 6 rep of 90° squats at 85% 1RM then 1 set of 5-m high skipping, in a straight line and then 5-m sprint. 2nd station: 6 rep of calf extension at 90% 1RM then 8 vertical jumps and then 3 high ball headers. 3rd station: 6 rep of leg extension exercise at 80% 1RM then 6 jump from the seated position than 3 drop jumps (60 cm), executing a soccer heading.     ↑ 9.2% 5m sprint ↑ 6.2% 15m sprint ↑12.6% SJ ↔ CMJ; 505 agility tests
  8 (17.4 ± 0.6) The same CT training but performed 2× a week     ↑ 9.2% 5m sprint ↑ 6.2% 15m sprint ↑12.6% SJ) ↔ CMJ; 505 agility tests
Mujika et al., [15] Elite/Spain/10 (18 ± 0.5) CT: 1st session - introduction session of hill sprinting (8% slope); 2nd session - dedicated to sled pulling sprint training, towing ~18% BM; 3rd, 4th, and 5th session (weeks 3 to 5) 3 series of 4 reps of calf rises (~35% BM) and parallel squats (~50% BM) and 2 repetitions per leg of hip flexions (~15% BM); 6th session - stair climbing: 18× (18 steps × 22.5 cm)/120-s rec (alternating single leg, double leg, single, double, frontal, and lateral step). Weight training emphasizing maximal concentric mobilization. Strength and power exercises in sessions 3 to 5 immediately followed soccer-specific activities such as jumps, accelerations, ball kicks, and offensive and defensive actions     ↑~2.8% 15m sprint† ↔ CMJ; CMJWAS; CMJ15-S; Agility 15m;
  10 (18 ± 0.7) Sprint training: 1st and 2nd session - 2× (4× 30-m); 3rd and 4th session- 3× (4× 30-m); 5th and 6th session- 4× (4× 30-m); 90-s rec between rep/180-s rec between sets     ↔ CMJ; CMJWAS; CMJ15-S; Agility 15m; 15m sprint
Manopoulos et al., [11] Amateurs/NS/10 (19.9 ± 0.4) CT: wk 1-2 : general strength (10 exercises/3 sets/15 to 20 rep); wk 3-4 : 3 sets/6 rep (5 different exercises as skipping, jumping on one leg and on both legs, jumping running forwards, backwards and to the side, jumping obstacles and kicking); wk 5-10 : (a) 3 sets × 6 instep kicks within a time of 5 s (b) 6 kicking’s with a 5-m run-up approach against resistance provided by a rubber band (RRB) attached on the ankle of the swinging leg (c) 3 × 10-min/5- or 8-a SSG, with or without loads (d) series of modified exercise sequences: 1st) 6 kicking’s (RRB), 3 jumps, isometry trunk with a player on the back (PB) in a semi-seated position for 6 s, 4 sideward jumps; 2nd) 6 leg extensions RRB, 3 headers, isometry ankle musculature, carrying PB for 6 s, 1 kicking; 3rd) 6 knee flexion repetitions RRB, 4 sideward jumps, 3 × 5-m sprints and a soccer kick 3×/wk/10 wks NS ↑ 13.9% MIVCleg press ↑ 14% MIVC/BW ↑ 29.1% F60 ↑ 17.2% F100 ↑ 30% EMG VL ↑ ~4% 10-m sprint ↑ ~10% BS with run up ↔ MCS
Impellizzeri et al., [12] Amateurs/Italian/37 (25 ± 4) PT on grass; vertical jumping: 15 sets in wk1; 20 sets wk2; 25 sets in wk3 to 4; always 10 rep per wk; bounding: 3 sets wk1; 4 sets wk2; 5 sets per wk in wk3-4; always 10 rep per wk; broad jumping: 5 sets × 8 rep wk1; 5 sets wk2; 7 sets wk3; 7 sets wk4; always 10 rep per wk2-4; drop jump: 3 sets × 5 rep wk1; 5 sets × 9 rep wk2; 6 sets × 15 rep per wk in wk3-4; rec 15 to 30 s between repetitions 1 to 2 min between sets 3×/wk/4 wks PS   ↑ 3.7% 10-m sprint ↑ 2.8% 20-m sprint ↑ 4.7% SJ ↑ 14.5% CMJ† ↑ 9% CMJ/SJ†
   Same PT protocol but performed on a different ground surface (sand)     ↑ 4.3% 10-m sprint ↑ 2.5% 20-m sprint ↑ 10% SJ† ↑ 6.4% CMJ; ↑ 3.7% CMJ/SJ
Sedano et al., [21] Elite U-19/Spain/11 (18.4 ± 1.1) PT: jump over hurdles: 16 to 26 sets/5 rep; horizontal jumps: 16 to 26 sets/5 rep; lateral jumps over hurdles: 16 to 26 sets/5 rep; wk1 - 270 jumps; wk2,4,9 - 300 jumps; wk3,8 - 240 jumps; wk5,7 - 330 jumps; wk6 - 180 jumps; wk10 - 390 jumps; 30-s rec between sets of 5 rep and 5 min after 4 sets of 5 reps 3×/wk/10 wks IS   ↑ 8% CMJ ↑ 5% CMJWAS ↑ 5.8% BSdl ↑ 6.4% BSndl ↑ 0.32% 10-m sprint ↔ SJ;
Thomas et al., [16] Semi-professional/UK/12 (17 ± 0.4) PT: DJ40group session began at 80 foot contacts and progressed to 120 by end of training program 2×/wk/6 wks IS   ↑ ~5% CMJ ↑ ~5% 505 agility test ↔ 5-, 10-, 15-, and 20-m sprint time
   PT: CMJgroup session began at 80 foot contacts and progressed to 120 by end of training program     ↑ ~7% CMJ ↑ ~10% 505 agility test ↔ 5-, 10-, 15-, and 20-m sprint time
Gorostiaga et al., [8] Amateurs/Spain/10 (17.3 ± 0.5) Explosive-strength training (low load weight training and plyometric and sprint exercises): full squat-lift (2 to 3 sets/2 to 6 rep/ 20 to 52 kg) and power clean (3 to 4 sets/ 3 to 4 rep/16 to 28 kg) 2×/wk; vertical CMJ to box (3 to 5 sets/5 to 8 rep/only in wk1 to 8); hurdle vertical jumps (3 sets/4 rep/only in the wk9 to 11); sprints (1 set/3 to 5 rep/15 to 40 m) performed 1×/wk; 2-min rec between sets and exercises 2×/wk/11 wks IS ↔ Hr13-14 km.h−1(bpm); ↔ La13-14 km.h−1(mM) ↑ 5.1% CMJ ↑ 7.5% CMJ20kg ↑ 13.9% CMJ30kg ↔ 5- and 15-m sprint; CMJ40-50-60-70kg
Billot et al., [28] Amateurs/French/10 (20 ± 2) ES: 2-min session on both quadriceps femoris muscle (36 contractions per session); knee fixed at 60° (0° corresponding to full extension of the leg); EMS 3 s long followed by a rest period of 17 s (duty cycle 15%); intensity range 60 to 120 mA (higher than 60% of muscle voluntary contraction) 3×/wk/5 wks IS ↑ 22.1% ECC IKE (−60°.s−1) ↑ 9.9% CON IKE (60°.s−1) ↑ 23.2% CON IKE (240°.s−1) ↑ 27.1% MIVCKE (60°) ↑ 9.6% BS without run up ↑ 5.6% BS with run up ↔ SJ; CMJ; CMJWAS; 10-m sprint; V10 m
  1. ↑, significant improvement; ↓, significant decrement; ↔, no significant alterations; †, significant differences between groups; ~, approximately and data extracted from graphs; NS, not specified; F/D, frequency and duration of training protocols; P, period of the soccer season; rec, recovery; RST, resistance strength training; PT, plyometric training; SP, sprint training; wk, week; PS, performed during preseason; IS, performed during in-season; ND, not defined; rep., repetitions; 1RM, one repetition maximum; 1RM/LLV, maximal strength in half-squat strength per lean leg volume; PPO, peak power output; F0, individual theoretical maximal force generated at zero pedal speed; Vopt, speed were the highest value of power is achieve; V0, maximal cycling speed corresponding to zero load; LLV, lean leg volume; m, meters; COD, change of direction; CMJ(10-20-30-40-50-60-70kg), countermovement jump with or without external (load); RSA, repeated sprint ability test; RE, running economy; VO2 max, maximal oxygen consumption; MAS, maximal aerobic speed; YYIE2, Yo-Yo intermittent endurance test level 2; DTT, Holff’s dribbling track test; MP60%-1RM-squat, mean power; MPP45%-1RM, jump squat; mean propulsive power; SJ, squat jump; ALB, alternate leg bound; DLHJ, double leg hurdle jump; SLFH, single leg forward hop; 4BT, four bounce test; SST, soccer-specific strength; SAQ, speed, agility and quickness; BF, body fat; Wpeak, leg cycling peak power; LMV, leg muscle volume; TMV, thigh muscle volume; MTCSA, mean thigh cross-sectional area; Vfirst step, velocity during the first step after the start of sprint test; Vfirst5-m, average running velocity during the first 5 m of the sprint test; Vmax, maximal running velocity; 5J, five jump test; MPV, maximal pedaling velocity; BHS, back half-squat at 90°; SU, step up on a bench with one leg; LCH, leg curls for hamstrings; DJ40cm, drop jump from 40-cm height; VH, vertical oriented exercises; VHS, vertical and horizontal oriented exercises; BM, body mass; IAT, individual anaerobic threshold; CMJ D, countermovement jump dominant leg; CMJ ND, countermovement jump non-dominant leg; OS, off-season; CON IKE(0. 4.18 and 5.24 rad/s), concentric isokinetic knee extensor peak torque (angular velocity); CON IKE50° (0 and 0.52 rad/s), concentric isokinetic knee extensor peak torque at 50° knee extension (angular velocity); PPO↑3.14 rad/s, peak power at angular velocity higher than 3.14 rad/s; PPO50°(↑3.14 rad/s), peak power at 50° knee extension (angular velocity); CON IKEVpeak(↑5.24 rad/s), concentric isokinetic knee extensor peak torque exerted at the instance of peak velocity (angular velocities higher than 5.24 rad/s); PPOVpeak (↑5.24 rad/s), peak power output exerted at the instance of peak velocity (angular velocities higher than 5.24 rad/s); MIVC50° knee extension, maximal isometric voluntary contraction of knee extensors (angle); BS with or without run up, ball speed after kicking with or without previous run up; CT, complex strength training; CMJWAS, counter movement jump with arm swing; CMJ15-s, counter movement jump during 15-s period; RRB, resistance provided by a rubber band; SSG, small sided game; PB, player on the back; MIVCleg press, maximal isometric voluntary contraction in the leg press machine (knee and hip angles of 110° and 90°, respectively; 180° = full extension); MIVC/BW, maximal force divided by body weight; F60−100, maximal force value during the first 60 or 100 ms of the contraction; EMG VL, electromyography activity of vastus medialis of the swinging leg (phase 3) normalized relatively to the maximal EMG value during kick; MCS, maximal cycling speed; CMJ/SJ, eccentric utilization ratio; BSdl, ball speed after kicking with dominant leg; BSndl, ball speed after kicking with non-dominant leg; UK, United Kingdom; Hr13- 14 km.h-1(bpm), - heart rate at 13 and 14 km.h−1; La13- 14 km.h-1(mM), blood lactate concentration at 13 and 14 km.h−1; V10m, velocity at 10-m sprint.