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Grégoire P Millet, Franck Brocherie, Raphael Faiss, Olivier Girard
The authors report that many LHTL studies in normobaric hypoxia (NH) "failed to show a positive outcome", which in our view is only partially true. In a cross-over design, we (Saugy et al. 2016) recently tested if LHTL in hypobaric hypoxia (HH) would lead to larger performance enhancement than in NH. Our hypothesis was that HH (i.e. natural altitude) would lead to larger enhancement than NH but the results were contrary to this hypothesis. So we cannot support the affirmation by Lundby & Robach that "natural altitude remains the best approach"...
October 17, 2016: Experimental Physiology
Amy L Woods, Avish P Sharma, Laura A Garvican-Lewis, Philo Saunders, Tony Rice, Kevin G Thompson
High altitude exposure can increase resting metabolic rate (RMR) and induce weight loss in obese populations, but there is a lack of research regarding RMR in athletes at moderate elevations common to endurance training camps. The present study aimed to determine whether four weeks of classical altitude training affects RMR in middle-distance runners. Ten highly-trained athletes were recruited for four weeks of endurance training undertaking identical programs at either 2200m in Flagstaff, Arizona (ALT, n=5) or 600m in Canberra, Australia (CON, n=5)...
August 24, 2016: International Journal of Sport Nutrition and Exercise Metabolism
B J Ryan, J A Goodrich, W Schmidt, L A Kane, W C Byrnes
Carbon monoxide (CO) rebreathing procedures are used to assess hemoglobin mass (Hbmass) but recent evidence suggests that CO is a signaling molecule that may alter physiological functions. We examined the effects of 10 days of intermittent, low-dose CO inhalation on Hbmass, aerobic performance predictors, and peak-power exercise tolerance. 18 recreationally-active men were randomized to either CO or placebo inhalation groups in a single-blind, pre-post parallel-groups trial. Primary outcomes were assessed before and after an intervention period during which subjects inhaled a bolus of 1...
October 2016: International Journal of Sports Medicine
David Montero, Candela Diaz-Cañestro, Stefanie Keiser, Carsten Lundby
BACKGROUND: Erythropoiesis is partly regulated through classic feedback pathways that govern blood volume (BV) as sensed by veno-atrial but also arterial stretch receptors. Hence, the total volume of red blood cells (RBCV) could be associated with arterial stiffness (AS), although such hypothesis has not yet been tested. Therefore, we sought to investigate the association of AS with hematological variables including RBCV. METHODS: Fourteen healthy physically active individuals volunteered for the study (age=23±2)...
October 15, 2016: International Journal of Cardiology
Jon Peter Wehrlin, Bernard Marti, Jostein Hallén
Fore more than a decade, the live high-train low (LHTL) approach, developed by Levine and Stray-Gundersen, has been widely used by elite endurance athletes. Originally, it was pointed out, that by living at moderate altitude, athletes should benefit from an increased red cell volume (RCV) and hemoglobin mass (Hbmass), while the training at low altitudes should prevent the disadvantage of reduced training intensity at moderate altitude. VO2max is reduced linearly by about 6-8 % per 1000 m increasing altitude in elite athletes from sea level to 3000 m, with corresponding higher relative training intensities for the same absolute work load...
2016: Advances in Experimental Medicine and Biology
Matthew W H Inness, François Billaut, Robert J Aughey
OBJECTIVES: To determine the efficacy of live-high train-low on team-sport athlete physical capacity and the time-course for adaptation. DESIGN: Pre-post parallel-groups. METHODS: Fifteen Australian footballers were matched for Yo-Yo Intermittent recovery test level 2 (Yo-YoIR2) performance and assigned to LHTL (n=7) or control (Con; n=8). LHTL spent 19 nights (3×5 nights, 1×4 nights, each block separated by 2 nights at sea level) at 3000-m simulated altitude (FIO2: 0...
January 28, 2016: Journal of Science and Medicine in Sport
A D Govus, P Peeling, C R Abbiss, N G Lawler, D W Swinkels, C M Laarakkers, K G Thompson, J J Peiffer, C J Gore, L A Garvican-Lewis
The post-exercise hepcidin response during prolonged (>2 weeks) hypoxic exposure is not well understood. We compared plasma hepcidin levels 3 h after exercise [6 × 1000 m at 90% of maximal aerobic running velocity (vVO2max )] performed in normoxia and normobaric hypoxia (3000 m simulate altitude) 1 week before, and during 14 days of normobaric hypoxia [196.2 ± 25.6 h (median: 200.8 h; range: 154.3-234.8 h) at 3000 m simulated altitude] in 10 well-trained distance runners (six males, four females)...
March 31, 2016: Scandinavian Journal of Medicine & Science in Sports
Benjamin J Ryan, Jesse A Goodrich, Walter F Schmidt, Ellen R Stothard, Kenneth P Wright, William C Byrnes
What is the central question of this study? Is haemoglobin mass (Hbmass) decreased following 4 days of head-down tilt bed rest (HDTBR), and does increased red blood cell (RBC) destruction mediate this adaptation? What is the main finding and its importance? Haemoglobin mass was increased immediately following HDTBR, before decreasing below baseline 5 days after return to normal living conditions. The transient increase in Hbmass might be the result of decreased RBC destruction, but it is also possible that spleen contraction after HDTBR contributed to this adaptation...
May 1, 2016: Experimental Physiology
Amelia J Carr, Philo U Saunders, Brent S Vallance, Laura A Garvican-Lewis, Christopher J Gore
This study examined effects of low altitude training and a live-high: train-low protocol (combining both natural and simulated modalities) on haemoglobin mass (Hbmass), maximum oxygen consumption (VO2max), time to exhaustion, and submaximal exercise measures. Eighteen elite-level race-walkers were assigned to one of two experimental groups; lowHH (low Hypobaric Hypoxia: continuous exposure to 1380 m for 21 consecutive days; n = 10) or a combined low altitude training and nightly Normobaric Hypoxia (lowHH+NHnight: living and training at 1380 m, plus 9 h...
December 2015: Journal of Sports Science & Medicine
Franck Brocherie, Grégoire P Millet, Anna Hauser, Thomas Steiner, Jon P Wehrlin, Julien Rysman, Olivier Girard
PURPOSE: We investigated association of hematological variables with specific fitness performance in elite team-sport players. METHODS: Hemoglobin mass (Hbmass) was measured in 25 elite field hockey players using the optimized (2 min) CO-rebreathing method. Hemoglobin concentration ([Hb]), hematocrit and mean corpuscular hemoglobin concentration (MCHC) were analyzed in venous blood. Fitness performance evaluation included a repeated-sprint ability (RSA) test (8 x 20 m sprints, 20 s of rest) and the Yo-Yo intermittent recovery level 2 (YYIR2)...
2015: PloS One
Anna Hauser, Laurent Schmitt, Severin Troesch, Jonas J Saugy, Roberto Cejuela-Anta, Raphael Faiss, Neil Robinson, Jon P Wehrlin, Grégoire P Millet
PURPOSE: To compare hemoglobin mass (Hb(mass)) changes during an 18-d live high-train low (LHTL) altitude training camp in normobaric hypoxia (NH) and hypobaric hypoxia (HH). METHODS: Twenty-eight well-trained male triathletes were split into three groups (NH: n = 10, HH: n = 11, control [CON]: n = 7) and participated in an 18-d LHTL camp. NH and HH slept at 2250 m, whereas CON slept, and all groups trained at altitudes <1200 m. Hb(mass) was measured in duplicate with the optimized carbon monoxide rebreathing method before (pre-), immediately after (post-) (hypoxic dose: 316 vs 238 h for HH and NH), and at day 13 in HH (230 h, hypoxic dose matched to 18-d NH)...
April 2016: Medicine and Science in Sports and Exercise
Andrew D Govus, Laura A Garvican-Lewis, Chris R Abbiss, Peter Peeling, Christopher J Gore
PURPOSE: To investigate the influence of daily oral iron supplementation on changes in hemoglobin mass (Hbmass) and iron parameters after 2-4 weeks of moderate altitude exposure. METHODS: Hematological data collected from 178 athletes (98 males, 80 females) exposed to moderate altitude (1,350-3,000 m) were analysed using linear regression to determine how altitude exposure combined with oral iron supplementation influenced Hbmass, total iron incorporation (TII) and blood iron parameters [ferritin and transferrin saturation (TSAT)]...
2015: PloS One
Laura A Garvican-Lewis, Iona Halliday, Chris R Abbiss, Philo U Saunders, Christopher J Gore
The influence of low natural altitudes (< 2000 m) on erythropoietic adaptation is currently unclear, with current recommendations indicating that such low altitudes may be insufficient to stimulate significant increases in haemoglobin mass (Hbmass). As such, the purpose of this study was to determine the influence of 3 weeks of live high, train high exposure (LHTH) at low natural altitude (i.e. 1800 m) on Hbmass, red blood cell count and iron profile. A total of 16 elite or well-trained runners were assigned into either a LHTH (n = 8) or CONTROL (n = 8) group...
June 2015: Journal of Sports Science & Medicine
D Reljic, J Feist, J Jost, M Kieser, B Friedmann-Bette
Rapid body mass loss (RBML) before competition was found to decrease hemoglobin mass (Hbmass ) in elite boxers. This study aimed to investigate the underlying mechanisms of this observation. Fourteen well-trained combat athletes who reduced body mass before competitions (weight loss group, WLG) and 14 combat athletes who did not practice RBML (control group, CON) were tested during an ordinary training period (t-1), 1-2 days before an official competition (after 5-7 days RBML in WLG, t-2), and after a post-competition period (t-3)...
May 2016: Scandinavian Journal of Medicine & Science in Sports
W H Inness M, François Billaut, Robert J Aughey
PURPOSE: To determine the time course for physical-capacity adaptations to intermittent hypoxic training (IHT) in team-sport athletes and the time course for benefits remaining after IHT. METHODS: A pre-post parallel-groups design was employed, with 21 Australian footballers assigned to IHT (n = 10) or control (CON; n = 11) matched for training load. IHT performed eleven 40-min bike sessions at 2500-m altitude over 4 wk. Yo-Yo Intermittent Recovery Test level 2 (Yo-Yo IR2) was performed before; after 3, 6, and 11 IHT sessions; and 30 and 44 d after IHT...
January 2016: International Journal of Sports Physiology and Performance
N Naef, T Steiner, J P Wehrlin
Duplicate haemoglobin mass (Hbmass) measurements are recommended before and after altitude training sojourns to identify individual adaptations in athletes with a high level of certainty. Duplicate measurements reduce typical error (TE) and disclose measurement outliers, but are usually made on separate days, which is not a practical protocol for routine services in elite sport settings. The aim of this study was therefore to investigate whether it is safe (carboxyhaemoglobin<10%) to measure Hbmass twice on the same day and to compare TE with measurements made on separate days...
March 25, 2015: International Journal of Sports Medicine
C Siebenmann, A Cathomen, M Hug, S Keiser, A K Lundby, M P Hilty, J P Goetze, P Rasmussen, C Lundby
High altitude (HA) exposure facilitates a rapid contraction of plasma volume (PV) and a slower occurring expansion of hemoglobin mass (Hbmass). The kinetics of the Hbmass expansion has never been examined by multiple repeated measurements, and this was our primary study aim. The second aim was to investigate the mechanisms mediating the PV contraction. Nine healthy, normally trained sea-level (SL) residents (8 males, 1 female) sojourned for 28 days at 3,454 m. Hbmass was measured and PV was estimated by carbon monoxide rebreathing at SL, on every 4th day at HA, and 1 and 2 wk upon return to SL...
November 15, 2015: Journal of Applied Physiology
Kari Margrethe Lundgren, Trine Karlsen, Øyvind Sandbakk, Philip E James, Arnt Erik Tjønna
PURPOSE: This study aims to compare maximal oxygen uptake (V˙O2max), blood volume (BV), hemoglobin mass (Hbmass), and brachial endothelial function, measured as flow-mediated dilatation (FMD), in international-level endurance athletes primarily exercising with the whole body (cross-country skiing), lower body (orienteering), or upper body (flatwater kayak). METHODS: Seventeen cross-country skiers, 15 orienteers, and 11 flatwater kayakers were tested for V˙O2max, BV, Hbmass, and FMD...
October 2015: Medicine and Science in Sports and Exercise
Franck Brocherie, Grégoire P Millet, Anna Hauser, Thomas Steiner, Julien Rysman, Jon P Wehrlin, Olivier Girard
PURPOSE: This study aims to investigate physical performance and hematological changes in 32 elite male team-sport players after 14 d of "live high-train low" (LHTL) training in normobaric hypoxia (≥14 h·d at 2800-3000 m) combined with repeated-sprint training (six sessions of four sets of 5 × 5-s sprints with 25 s of passive recovery) either in normobaric hypoxia at 3000 m (LHTL + RSH, namely, LHTLH; n = 11) or in normoxia (LHTL + RSN, namely, LHTL; n = 12) compared with controlled "live low-train low" (LLTL; n = 9) training...
October 2015: Medicine and Science in Sports and Exercise
Benjamin J Ryan, Nadine B Wachsmuth, Walter F Schmidt, William C Byrnes, Colleen G Julian, Andrew T Lovering, Andrew W Subudhi, Robert C Roach
It is classically thought that increases in hemoglobin mass (Hbmass) take several weeks to develop upon ascent to high altitude and are lost gradually following descent. However, the early time course of these erythropoietic adaptations has not been thoroughly investigated and data are lacking at elevations greater than 5000 m, where the hypoxic stimulus is dramatically increased. As part of the AltitudeOmics project, we examined Hbmass in healthy men and women at sea level (SL) and 5260 m following 1, 7, and 16 days of high altitude exposure (ALT1/ALT7/ALT16)...
2014: PloS One
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