title: The metabolic, hormonal, biochemical, and neuromuscular function responses to a backward sled drag training session.
abstract: We examined the metabolic, hormonal, biochemical, and neuromuscular function (NMF) responses to a backward sled drag training session (STS) in strength-trained men (n = 11). After baseline collection of saliva (testosterone and cortisol), whole blood (lactate and creatine kinase [CK]), and countermovement jumps (peak power output), participants completed 5 sets of 2 × 20-m (30 second-recovery between drags and 120 second-recovery between sets) maximal backward sled drags (loaded with 75% body mass). Participants were retested immediately, 15 minutes, 1, 3, and 24 hours after STS. Peak power output decreased after STS (baseline, 4,445 ± 705 vs. 0 minute, 3,464 ± 819 W; p = 0.001) and remained below baseline until recovering at both the 3- and 24-hour time points. No changes in CK levels were seen at any time point after STS. Blood lactate increased immediately after STS (baseline, 1.7 ± 0.5 vs. 0 minute, 12.4 ± 2.6 mmol·L-1; p = 0.001) and remained elevated at 60 minutes (3.8 ± 1.9 mmol·L-1; p = 0.004) before returning to baseline at 3 and 24 hours. Testosterone peaked at 15 minutes post (baseline, 158 ± 45 vs. 15 minutes, 217 ± 49 pg·ml-1; p < 0.001) before decreasing below baseline at the 3-hour time point (119 ± 34 pg·ml-1; p = 0.008), but then increased again above baseline at 24 hours (187 ± 56 pg·ml-1; p = 0.04). Cortisol tended to increase at 15 minutes (baseline, 3.4 ± 1.8 vs. 15 minutes, 5.2 ± 2.7 ng·ml-1; p = 0.07) before declining below baseline at 3 hours (1.64 ± 0.93 ng·ml-1; p = 0.012) and returning to baseline concentrations at 24 hours. In conclusion, sled dragging provides an effective metabolic stimulus, with NMF restored after ≤3 hours of recovery. Characterizing the recovery time course after sled training may aid in athlete training program design.
authors.affiliation: 1Department of Sport and Exercise Science, School of Life Science, Northumbria University, Newcastle upon Tyne, United Kingdom; 2Health and Sport Portfolio, College of Engineering, Swansea University, Swansea, United Kingdom; 3Hamlyn Center, Institute of Global Health Innovation, Imperial College, London, United Kingdom; and 4Sport and Exercise Science, University of Bath, Bath, United Kingdom.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: West
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Cunningham
authors.forename: Charlotte V
authors.initials: CV
authors.lastname: Finn
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Scott
authors.forename: Blair T
authors.initials: BT
authors.lastname: Crewther
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Cook
authors.forename: Liam P
authors.initials: LP
authors.lastname: Kilduff
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009068:Movement / Q000502:physiology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods / Q000502:physiology*; D020127:Recovery of Function; D012463:Saliva / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: D019344:Lactic Acid; D013739:Testosterone; D003402:Creatine Kinase; D006854:Hydrocortisone