title: Effects of air-pulsed cryotherapy on neuromuscular recovery subsequent to exercise-induced muscle damage.
abstract: BACKGROUND
  Localized cooling has been proposed as an effective strategy to limit the deleterious effects of exercise-induced muscle damage on neuromuscular function. However, the literature reports conflicting results.
  
  
  OBJECTIVE
  This randomized controlled trial aimed to determine the effects of a new treatment, localized air-pulsed cryotherapy (-30°C), on the recovery time-course of neuromuscular function following a strenuous eccentric exercise.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  A total of 24 participants were included in either a control group (CONT) or a cryotherapy group (CRYO). Immediately after 3 sets of 20 maximal isokinetic eccentric contractions of elbow flexors, and then 1, 2, and 3 days after exercise, the CRYO group received a cryotherapy treatment (3 × 4 minutes at -30°C separated by 1 minute). The day before and 1, 2, 3, 7, and 14 days after exercise, several parameters were quantified: maximal isometric torque and its associated maximal electromyographic activity recorded by a 64-channel electrode, delayed-onset muscle soreness (DOMS), biceps brachii transverse relaxation time (T2) measured using magnetic resonance imaging, creatine kinase activity, interleukin-6, and C-reactive protein.
  
  
  RESULTS
  Maximal isometric torque decreased similarly for the CONT (-33% ± 4%) and CRYO groups (-31% ± 6%). No intergroup differences were found for DOMS, electromyographic activity, creatine kinase activity, and T2 level averaged across the whole biceps brachii. C-reactive protein significantly increased for CONT (+93% at 72 hours, P < .05) but not for CRYO. Spatial analysis showed that cryotherapy delayed the significant increase of T2 and the decrease of electromyographic activity level for CRYO compared with CONT (between day 1 and day 3) in the medio-distal part of the biceps brachii.
  
  
  CONCLUSIONS
  Although some indicators of muscle damage after severe eccentric exercise were delayed (ie, local formation of edema and decrease of muscle activity) by repeated air-pulsed cryotherapy, we provide evidence that this cooling procedure failed to improve long-term recovery of muscle performance.
  
  
  CONCLUSIONS
  Four applications of air-pulsed cryotherapy in the 3 days after a strenuous eccentric exercise are ineffective overall in promoting long-term muscle recovery. Further studies taking into account the amount of exercise-induced muscle damage would allow investigators to make stronger conclusions regarding the inefficiency of this recovery modality.
authors.affiliation: Institut National du Sport, de l'Expertise et de la Performance, Service Recherche, 11, Avenue du Tremblay, 75012 Paris, France. gael.guilhem@insep.fr
authors.forename: Gaël
authors.initials: G
authors.lastname: Guilhem
authors.forename: François
authors.initials: F
authors.lastname: Hug
authors.forename: Antoine
authors.initials: A
authors.lastname: Couturier
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Regnault
authors.forename: Laure
authors.initials: L
authors.lastname: Bournat
authors.forename: Jean-Robert
authors.initials: JR
authors.lastname: Filliard
authors.forename: Sylvain
authors.initials: S
authors.lastname: Dorel
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001132:Arm; D015415:Biomarkers / Q000097:blood; D017679:Cryotherapy / Q000379:methods*; D004576:Electromyography; D015444:Exercise; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009119:Muscle Contraction; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000293:injuries* / Q000503:physiopathology; D020127:Recovery of Function; D013180:Sprains and Strains / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers
keywords: cold application; damage markers; eccentric contraction; edema; fatigue; high-density EMG