title: Asymmetry of quadriceps muscle oxygenation during elite short-track speed skating.
abstract: OBJECTIVE
  It has been suggested that, because of the low sitting position in short-track speed skating, muscle blood flow is restricted, leading to decreases in tissue oxygenation. Therefore, wearable wireless-enabled near-infrared spectroscopy (NIRS) technology was used to monitor changes in quadriceps muscle blood volume and oxygenation during a 500-m race simulation in short-track speed skaters.
  
  
  METHODS
  Six elite skaters, all of Olympic standard (age = 23 ± 1.8 yr, height = 1.8 ± 0.1 m, mass = 80.1 ± 5.7 kg, midthigh skinfold thickness = 7 ± 2 mm), were studied. Subjects completed a 500-m race simulation time trial (TT). Whole-body oxygen consumption was simultaneously measured with muscle oxygenation in right and left vastus lateralis as measured by NIRS.
  
  
  RESULTS
  Mean time for race completion was 44.8 ± 0.4 s. VO2 peaked 20 s into the race. In contrast, muscle tissue oxygen saturation (TSI%) decreased and plateaued after 8 s. Linear regression analysis showed that right leg TSI% remained constant throughout the rest of the TT (slope value = 0.01), whereas left leg TSI% increased steadily (slope value = 0.16), leading to a significant asymmetry (P < 0.05) in the final lap. Total muscle blood volume decreased equally in both legs at the start of the simulation. However, during subsequent laps, there was a strong asymmetry during cornering; when skaters traveled solely on the right leg, there was a decrease in its muscle blood volume, whereas an increase was seen in the left leg.
  
  
  CONCLUSIONS
  NIRS was shown to be a viable tool for wireless monitoring of muscle oxygenation. The asymmetry in muscle desaturation observed on the two legs in short-track speed skating has implications for training and performance.
authors: Department of Biological Sciences, University of Essex, United Kingdom. chesfo@essex.ac.uk
authors: Catherine Mary
authors: CM
authors: Hesford
authors: Stewart J
authors: SJ
authors: Laing
authors: Marco
authors: M
authors: Cardinale
authors: Chris E
authors: CE
authors: Cooper
mesh_terms: D001810:Blood Volume; D006801:Humans; D007866:Leg / Q000098:blood supply*; D016014:Linear Models; D008297:Male; D009010:Monte Carlo Method; D010101:Oxygen Consumption / Q000502:physiology*; D052097:Quadriceps Muscle / Q000098:blood supply / Q000378:metabolism*; D012039:Regional Blood Flow; D012861:Skating / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D014741:Video Recording; D055815:Young Adult