Recovery kinetics following sprint training: resisted versus unresisted sprints

PurposeTo determine the recovery kinetics of performance and exercise-induced muscle damage following different sprint-training protocols.MethodsIn a crossover design, ten male and female athletes (20.6 & PLUSMN; 2.4 years) performed 2 x (3 x 20 m: 2 min rest) and 1x (3 x 30 m: 3 min rest) of: (a) unresisted sprints (UST), (b) resisted sprints with 10% of body mass (BM) load (RST10), (c) resisted sprints with 20% BM load (RST20), against a control trial (no-training).ResultsBlood lactate (mmol/L) increased post-training versus pre-training in all sprint-training trials (6.7 & PLUSMN; 2.4 vs 1.2 & PLUSMN; 0.2, 5.6 & PLUSMN; 2.4 vs 1.3 & PLUSMN; 0.3, 7.3 & PLUSMN; 2.7 vs 1.2 & PLUSMN; 0.3, in UST, RST10, RST20, respectively), as did creatine kinase (U/L) 24 h, 48 h and 72 h post-training (UST: 251 & PLUSMN; 173, 238 & PLUSMN; 154, 209 & PLUSMN; 115 vs 155 & PLUSMN; 9, RST10: 252 & PLUSMN; 134, 240 & PLUSMN; 83, 218 & PLUSMN; 103 vs 164 & PLUSMN; 106; RST20: 237 & PLUSMN; 133, 323 & PLUSMN; 303, 262 & PLUSMN; 184 vs 179 & PLUSMN; 106, respectively). DOMS of knee-extensors (KE) and knee-flexors (KF) increased post-training up to 72 h in all sprint-training trials versus pre-training (ranging from 1.6 & PLUSMN; 1.3 to 3.8 & PLUSMN; 2.8 vs 1.0 & PLUSMN; 0, respectively). Eccentric torque (N m) of the KE of the non-dominant limb, decreased 24 h post-training versus pre-training in all sprint-training trials (UST: 249 & PLUSMN; 49 vs 266 & PLUSMN; 54; RST10: 229 & PLUSMN; 52 vs 273 & PLUSMN; 72; RST20: 253 & PLUSMN; 6 vs 262 & PLUSMN; 56), as did that of the KF of the dominant limb (UST: 135 & PLUSMN; 29 vs 144 & PLUSMN; 26; RST10: 130 & PLUSMN; 29 vs 140 & PLUSMN; 25; RST20: 139 & PLUSMN; 33 vs 142 & PLUSMN; 26). 10-m sprint-time (s) increased 48 h post-training versus pre-training (1.81 & PLUSMN; 0.15 vs 1.77 & PLUSMN; 0.11), and 30-m sprint-time increased 24 h, 48 h, 72 h post-training versus pre-training (4.35 & PLUSMN; 0.36, 4.40 & PLUSMN; 0.44, 4.33 & PLUSMN; 0.41 vs 4.21 & PLUSMN; 0.34, respectively), only in RST20.ConclusionsUnresisted and resisted sprint-training induces prolonged reduction of muscle strength (24 h), and sprinting performance (72 h), associated with prolonged increase of DOMS and CK (72 h).

Automated summary

The study indicates that both unresisted and resisted sprint training can lead to prolonged reduction in muscle strength and sprinting performance, as well as increased DOMS and CK levels.