Cowan, Daniel

Faulkner, James

Fryer, Simon M

Stone, Keeron J

Stoner, Lee

Wilhelmsen, Andrew

University of Gloucestershire Research Repository 

This is a peer-reviewed, post-print (final draft post-refereeing) version of the following published document and is licensed under All Rights Reserved license:Wilhelmsen, Andrew and Stone, Keeron J and Cowan, Daniel and Stoner, Lee and Faulkner, James and Fryer, Simon M (2016) Changes in oxygenation kinetics following. training in normoxia and normobaric hypoxia. In: BASES 2016, 29 - 30 November 2016, Nottingham, UK. Official URL: http://www.basesconference.co.uk/EPrint URI: http://eprints.glos.ac.uk/id/eprint/3924Disclaimer The University of Gloucestershire has obtained warranties from all depositors as to their title in the material deposited and as to their right to deposit such material.  The University of Gloucestershire makes no representation or warranties of commercial utility, title, or fitness for a particular purpose or any other warranty, express or implied in respect of any material deposited.  The University of Gloucestershire makes no representation that the use of the materials will not infringe any patent, copyright, trademark or other property or proprietary rights.  The University of Gloucestershire accepts no liability for any infringement of intellectual property rights in any material deposited but will remove such material from public view pending investigation in the event of an allegation of any such infringement. PLEASE SCROLL DOWN FOR TEXT.IntroductionMethodsReferencesConclusionsResultsChanges in oxygenation kinetics following.training in normoxia and normobaric hypoxia.Andrew Wilhelmsen1, Keeron Stone1, Daniel Cowen1 Lee Stoner2, James Faulkner3 & Simon Fryer11School of Sport and Exercise, University of Gloucestershire, 2Massey University and 3University of Winchester.Figure 1. Assessment of oxygenation kinetics using near-infraredspectroscopy (left) and optode placement over the flexordigitorum profundus (right).Altitude camps are popular amongst elite endurance athletesseeking performance enhancement, however are not feasible for all.Subsequently, live-low-train-high protocols may be undertakenhaphazardly in attempts to reap similar adaptations. The effects ofexercise training in hypoxia on skeletal muscle oxygenationresponses remain poorly understood (Bonetti & Hopkins, 2009).Near-infrared spectroscopy (NIRS) has been used reliably to monitortraining-induced changes in forearm oxygenation kinetics (Ryan etal., 2013). Wrist flexors are commonly studied due to their typicallyuntrained nature and low adiposity (Fryer et al., 2015).The purpose of this study was to determine the effects of handgriptraining in normobaric hypoxia and normoxia on the oxidativecapacity index of the flexor digitorum profundus (FDP).Nine recreationally trained, healthy males (mean ± SD, age: 20.7 ±1.1 years; stature: 1.77 ± 0.08 m; body mass: 84.0 ± 14.2 kg) werestudied. In a repeated measures, crossover design, participantscompleted 4 weeks of progressive endurance training of the wristflexor muscles in normoxia and normobaric hypoxia (fraction ofinspired oxygen = 14%). Training sessions comprised 30 min ofcontinuous handgrip exercise. Contraction frequency increased from0.3 Hz in week 1 to 1.2Hz in week four (~540 to ~2160 repetitions persession, respectively). Sessions ended with 60 s of ͚sprint͛ contractions.Changes in oxygenation kinetics of the FDP were assessed pre, postand 1, 2, 3, and 4 weeks post training. Briefly, participants wereinvited to lay supine for 20 min, before a tourniquet (Hokanson Inc,WA, USA) was utilised to sustain 5 min of brachial ischemia.Following rapid cuff deflation, time to half recovery (t½rec) of thetissue saturation index was determined (McCully et al., 1994) usingNIRS (Artinis Medical Systems BV, Ge, NL).• Oxygenation kinetics improved with 4 weeks of training innormoxia (27% faster t1/2rec), but not in normobaric hypoxia.• In normoxia, both the magnitude of change and the rate ofdecline were consistent with previous findings (Ryan et al., 2013).• Endurance training in normobaric hypoxia may blunt physiologicaladaptations observed in normoxia.Two-way repeated measures ANOVA revealed a significant main effectfor condition (P = 0.03, ��2 = 0.834). One-way ANOVAs revealed asignificant difference across time in normoxia only (P = 0.01, ��2 =0.305). Post t½rec (6.79±2.18s) was 27% quicker than pre (9.25±3.41s,P=0.03). Post 2, 3, and 4 weeks were slower than post (all P<0.05).Figure 2. Time to half recovery of tissue saturation index of the flexordigitorum profundus following training and detraining in normoxiaand normobaric hypoxia. Results are mean ± SD.Figure 3. Percent change in time to half recovery of the flexor digitorumprofundus following training in normoxia. A detraining half-time of 13.4days was estimated using the regression equation of a logarithmic trendline fitted to the data. Results are mean ± SD.Bonetti, D., &Hopkins,W. (2009). Sea-level exercise performance following adaptation to hypoxia. SportsMedicine, 39(2), 107-127.Fryer, S., Stoner, L., Scarrott, C., Lucero, A., Witter, T., Love, R., ... Draper, N. (2015). Forearm oxygenation and blood flow kineticsduring a sustained contraction inmultiple ability groups of rock climbers. Journal of Sports Sciences, 33(5), 518-526.McCully, K. K., Lotti, S., Kendrick, K., Wang, Z., Posner, J. D., Leigh, J., Jr., & Chance, B. (1994). Simultaneous in vivomeasurementsof HbO2 saturation and PCr kinetics after exercise in normal humans. Journal of Applied Physiology, 77(1), 5-10.Ryan, T. E., Southern, W. M., Brizendine, J. T., & McCully, K. K. (2013). Activity-induced changes in skeletal muscle metabolismmeasuredwith optical spectroscopy.Medicine and Science in Sports and Exercise, 45(12), 2347-2352.

Changes in oxygenation kinetics following. training in normoxia and normobaric hypoxia

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