title: Differentiating swelling and hypertrophy through indirect assessment of muscle damage in untrained men following repeated bouts of resistance exercise.
abstract: OBJECTIVE
  To examine the swelling response and other markers of muscle damage throughout the early portions of a training program (Experiment 1). We also determined if a "swollen" muscle could swell further following additional exercise (Experiment 2).
  
  
  METHODS
  Nine males performed four sets of biceps curls (or time-matched rest on control arm) at 70% of their one-repetition maximum three times over 8 days. Muscle thickness and torque were measured before and after exercise as well as on the days in between. Soreness was measured at the beginning of each day (Experiment 1). On the final day (Experiment 2), participants performed two bouts of exercise, followed by additional measures of muscle thickness.
  
  
  RESULTS
  Following three bouts of exercise, muscle thickness was elevated over baseline (mean of visit 9 pre to visit 2 pre, 95% CI) at the 50% [0.21 (0.07, 0.34) cm], 60% [0.21 (0.02, 0.39) cm], and 70% [0.21 (0.06, 0.36) cm] sites. However, differences from a non-exercise control were only observed immediately following bouts of exercise (indicative of acute swelling). Torque was lower at every time point following the first bout of exercise and remained suppressed relative to pre at visit 9 [-6.1 (-11.7, -0.47 Nm] in the experimental arm. Experiment 2 found that a swollen muscle could not appreciably swell more.
  
  
  CONCLUSIONS
  Resting levels of muscle thickness do not appear to change beyond what occurs following the first naïve bout of exercise. Also, the acute swelling response may be used to differentiate swelling from muscle growth.
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Buckner
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Dankel
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Mattocks
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Jessee
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: J Grant
authors.initials: JG
authors.lastname: Mouser
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: Brittany R
authors.initials: BR
authors.lastname: Counts
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA.
authors.forename: Gilberto C
authors.initials: GC
authors.lastname: Laurentino
authors.affiliation: Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, P.O. Box 1848, University, MS, 38677, USA. jploenne@olemiss.edu.
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Loenneke
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology; D015444:Exercise; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D063806:Myalgia / Q000503:physiopathology*; D011897:Random Allocation; D019415:Torque
keywords: Edema; Muscle growth; Swelling