title: Comparisons between twice-daily and once-daily training sessions in male weight lifters.
abstract: BACKGROUND
  Many elite athletes use increased daily training frequencies as a means to increase training load without substantial published literature to support this practice.
  
  
  OBJECTIVE
  To compare the physiological responses to twice- and once-daily training sessions with similar training volumes.
  
  
  METHODS
  Ten nationally competitive male weightlifters (age 20.5 +/- 1.2 y, body mass 92.9 +/- 23.6 kg, training history 5.5 +/- 1.5 y) were matched on body mass and training experience, then randomly assigned to train either once or twice daily for 3 wk. Isometric knee-extension strength (ISO), muscle cross-sectional area, vertical-jump peak power, resting hormone concentrations, neuromuscular activation (EMG), and weightlifting performance were obtained before and after the experimental training period.
  
  
  RESULTS
  All dependent measures before the training intervention were similar for both groups. A 2-way repeated-measures ANOVA did not reveal any significant main effects (group or trial) or interaction effects (group x trial) for any of the dependent variables. There were also no significant group differences when parameters were expressed as percentage change, but the twice-daily training group had a greater percentage change in ISO (+5.1% vs +3.2%), EMG (+20.3% vs +9.1%), testosterone (+10.5% vs +6.4%), and testosterone:cortisol ratio (-10.5% vs +1.3%) than did the once-daily training group.
  
  
  CONCLUSIONS
  There were no additional benefits from increased daily training frequency in national-level male weightlifters, but the increase in ISO and EMG activity for the twice-daily group might provide some rationale for dividing training load in an attempt to reduce the risk of overtraining.
authors.affiliation: Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hartman
authors.forename: Brandon
authors.initials: B
authors.lastname: Clark
authors.forename: Debra A
authors.initials: DA
authors.lastname: Bembens
authors.forename: J Lon
authors.initials: JL
authors.lastname: Kilgore
authors.forename: Michael G
authors.initials: MG
authors.lastname: Bemben
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004576:Electromyography; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D013739:Testosterone / Q000097:blood; D013997:Time Factors; D014891:Weight Lifting / Q000502:physiology*
chemical_list: D013739:Testosterone; D006854:Hydrocortisone