title: Neuromuscular Changes and Damage after Isoload versus Isokinetic Eccentric Exercise.
abstract: This study compared the effects of isoload (IL) and isokinetic (IK) knee extensor eccentric exercises on changes in muscle damage and neuromuscular parameters to test the hypothesis that the changes would be different after IL and IK exercises.
  
  
  
  Twenty-two young men were paired based on their strength and placed in the IL (N = 11) or the IK (N = 11) group. The IL group performed 15 sets of 10 eccentric contractions with a 150% of predetermined one-repetition maximum load. The IK group performed 15 sets of several maximal eccentric contractions matched set by set for the total amount of work and mean angular velocity with the IL group. Muscle damage markers (voluntary isometric peak torque, muscle soreness, and creatine kinase activity) and neuromuscular variables (e.g., voluntary activation, H-reflex, M-wave, and evoked torque) were measured before, immediately after, and 24, 48, 72, and 96 h postexercise.
  
  
  
  Voluntary isometric peak torque decreased to the same extent (P = 0.94) in both groups immediately after (IL = -40.6% ± 13.8% vs IK = -42.4% ± 10.2%) to 96 h after the exercise (IL = -21.8% ± 28.5% vs IK = -26.7% ± 23.5%). Neither peak muscle soreness (IL = 48.1 ± 28.2 mm vs IK = 54.7 ± 28.9 mm, P = 0.57) nor creatine kinase activity (IL = 12,811 ± 22,654 U·L vs IK = 15,304 ± 24,739 U·L, P = 0.59) significantly differed between groups. H-reflex (IL = -23% vs IK = -35%) and M-wave (IL = -10% vs IK = -17%) significantly decreased immediately postexercise similarly between groups.
  
  
  
  The changes in muscle damage and neuromuscular function after the exercise are similar between IL and IK, suggesting that resistance modality has little effects on acute muscle responses.
authors.affiliation: 1Laboratory "Movement, Interactions, Performance" (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, FRANCE; 2Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, AUSTRALIA; 3Department of Physical Medicine and Rehabilitation, Nantes University Hospital, Saint-Jacques Hospital, Nantes, FRANCE; and 4French Institute of Sport (INSEP), Research Department, Laboratory Sport, Expertise and Performance (EA 7370), Paris, FRANCE.
authors.forename: Valentin
authors.initials: V
authors.lastname: Doguet
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nosaka
authors.forename: Mathieu
authors.initials: M
authors.lastname: Plautard
authors.forename: Raphaël
authors.initials: R
authors.lastname: Gross
authors.forename: GaËL
authors.initials: G
authors.lastname: Guilhem
authors.forename: Arnaud
authors.initials: A
authors.lastname: Guével
authors.forename: Marc
authors.initials: M
authors.lastname: Jubeau
mesh_terms: D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007717:Knee / Q000502:physiology; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000201:enzymology / Q000293:injuries* / Q000294:innervation / Q000503:physiopathology*; D063806:Myalgia / Q000209:etiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003402:Creatine Kinase