Neuromuscular electrical stimulation (NMES) during recovery from exercise: A systematic review

The use of sub-tetanic low intensity neuromuscular electrical stimulation (NMES) for thepurpose of promoting recovery from exercise has increased in recent years. The aim of thissystematic review was to assess the effects of NMES on exercise recovery. A computeriseddatabase search of PubMed, CINAHL Plus, Sport Discus and Cochrane Library electronicdatabases was conducted for the time period Jan 1st 1970 to Mar 8th 2012. Only studieswhich used healthy uninjured humans and motor-threshold electrical stimulation compared toat least one other recovery modality for the purpose of promoting recovery from exercisewere eligible for selection. Thirteen studies satisfied the inclusion criteria and were includedfor analysis (11 randomised crossover trials (RXTs), 1 randomised control trial (RCT) and 1classified as other (OTH)). A quality assessment rating of the studies was performed usingan extended version of The Cochrane Collaborations Tool for Assessing Risk of Bias.Because of the heterogeneity of the study protocols, a qualitative review (best evidencesynthesis) was performed for all outcomes, while the results for blood lactate (BLa) were alsoincluded in a meta-analysis. Eight studies were classified as high quality, 4 as mediumquality, and one as low quality. Three studies found a positive outcome for a subjectivemeasure of muscle pain, 3 for BLa, one for lowering creatine kinase, and only one for aperformance parameter. The meta-analysis showed no evidence in favour of NMES vs.active (ACT) and mixed evidence vs. passive (PAS) recovery for BLa. In conclusion, whilstthere may be some subjective benefits for post-exercise recovery, evidence is not convincingto support NMES for enhancing subsequent performance.