Blood Volumes Following Preseason Heat Versus Altitude: A Case Study of Australian Footballers.

Purpose: There is debate as to which environmental intervention produces the most benefit for team sport athletes, particularly comparing heat and altitude. This quasi-experimental study aimed to compare blood volume (BV) responses with heat and altitude training camps in Australian footballers.

Methods: The BV of 7 professional Australian footballers (91.

The Potential to Change Pacing and Performance During 4000-m Cycling Time Trials Using Hyperoxia and Inspired Gas-Content Deception.

Purpose: Determine if a series of trials with fraction of inspired oxygen (FiO2) content deception could improve 4000-m cycling time-trial (TT) performance.

Methods: Fifteen trained male cyclists (mean ± SD: body mass 74.2 ± 8.

Training Quantification and Periodization during Live High Train High at 2100 M in Elite Runners: An Observational Cohort Case Study.

The questionable efficacy of Live High Train High altitude training (LHTH) is compounded by minimal training quantification in many studies. We sought to quantify the training load (TL) periodization in a cohort of elite runners completing LHTH immediately prior to competition. Eight elite runners (6 males, 2 females) with a V̇O of 70 ± 4 mL·kg·min were monitored during 4 weeks of sea-level training, then 3-4 weeks LHTH in preparation for sea-level races following descent to sea-level.

Characterizing the plasma metabolome during 14 days of live-high, train-low simulated altitude: A metabolomic approach.

New Findings: What is the central question of this study? Does 14 days of live-high, train-low simulated altitude alter an individual's metabolomic/metabolic profile? What is the main finding and its importance? This study demonstrated that ∼200 h of moderate simulated altitude exposure resulted in greater variance in measured metabolites between subject than within subject, which indicates individual variability during the adaptive phase to altitude exposure. In addition, metabolomics results indicate that altitude alters multiple metabolic pathways, and the time course of these pathways is different over 14 days of altitude exposure. These findings support previous literature and provide new information on the acute adaptation response to altitude.

Training to Compete at Altitude:Natural Altitude or Simulated Live High:Train Low?

Purpose: To compare the effects of natural altitude training (NAT) and simulated (SIM) live high:train low altitude training on road-race walking performance (min), as well as treadmill threshold walking speed (km·h) at 4 mmol·L and maximal oxygen consumption, at 1380 m.

Methods: Twenty-two elite-level male (n = 15) and female (n = 7) race walkers completed 14 d of NAT at 1380 m (n = 7), SIM live high:train low at 3000:600 m (n = 7), or control conditions (600-m altitude; CON, n = 8). All preintervention and postintervention testing procedures were conducted at 1380 m and consisted of an incremental treadmill test, completed prior to a 5 × 2-km road-race walking performance test.

Normobaric Hypoxia Reduces V˙O2 at Different Intensities in Highly Trained Runners.

Introduction: We sought to determine the effect of low and moderate normobaric hypoxia on oxygen consumption and anaerobic contribution during interval running at different exercise intensities.

Methods: Eight runners (age, 25 ± 7 yr, V˙O2max: 72.1 ± 5.

Improved Performance in National-Level Runners With Increased Training Load at 1600 and 1800 m.

Purpose: To determine the effect of altitude training at 1600 and 1800 m on sea-level (SL) performance in national-level runners.

Methods: After 3 wk of SL training, 24 runners completed a 3-wk sojourn at 1600 m (ALT1600, n = 8), 1800 m (ALT1800, n = 9), or SL (CON, n = 7), followed by up to 11 wk of SL racing. Race performance was measured at SL during the lead-in period and repeatedly postintervention.

Intravenous Iron Does Not Augment the Hemoglobin Mass Response to Simulated Hypoxia.

Purpose: Iron is integral for erythropoietic adaptation to hypoxia, yet the importance of supplementary iron compared with existing stores is poorly understood. The aim of the present study was to compare the magnitude of the hemoglobin mass (Hbmass) in response to altitude in athletes with intravenous (IV), oral, or placebo iron supplementation.

Methods: Thirty-four, nonanemic, endurance-trained athletes completed 3 wk of simulated altitude (3000 m, 14 h·d), receiving two to three bolus iron injections (ferric carboxymaltose), daily oral iron supplementation (ferrous sulfate), or a placebo, commencing 2 wk before and throughout altitude exposure.

Validation of a blood marker for plasma volume in endurance athletes during a live-high train-low altitude training camp.

Altitude is a confounding factor within the Athlete Biological Passport (ABP) due, in part, to the plasma volume (PV) response to hypoxia. Here, a newly developed PV blood test is applied to assess the possible efficacy of reducing the influence of PV on the volumetric ABP markers; haemoglobin concentration ([Hb]) and the OFF-score. Endurance athletes (n=34) completed a 21-night simulated live-high train-low (LHTL) protocol (14 h.

The athlete's hematological response to hypoxia: A meta-analysis on the influence of altitude exposure on key biomarkers of erythropoiesis.

Altitude training is associated with changes in blood markers, which can confound results of the Athlete?s Biological Passport (ABP). This meta-analysis aims to describe the fluctuations during- and post-altitude in key ABP variables; hemoglobin concentration ([Hb]), square-root transformed reticulocyte percentage (sqrt(retic%)) and the OFF-score. Individual de-identified raw data were provided from 17 studies.

Influence of combined iron supplementation and simulated hypoxia on the haematological module of the athlete biological passport.

The integrity of the athlete biological passport (ABP) is underpinned by understanding normal fluctuations of its biomarkers to environmental or medical conditions, for example, altitude training or iron deficiency. The combined impact of altitude and iron supplementation on the ABP was evaluated in endurance-trained athletes (n = 34) undertaking 3 weeks of simulated live-high: train-low (14 h.d , 3000 m).

Temporal changes in physiology and haematology in response to high- and micro-doses of recombinant human erythropoietin.

There is evidence to suggest athletes have adopted recombinant human erythropoietin (rHuEPO) dosing regimens that diminish the likelihood of being caught by direct detection techniques. However, the temporal response in physiology, performance, and Athlete Biological Passport (ABP) parameters to such regimens is not clearly understood. Participants were assigned to a high-dose only group (HIGH, n = 8, six rHuEPO doses of 250 IU/kg over two weeks), a combined high micro-dose group (COMB, n = 8, high-dose plus nine rHuEPO micro-doses over a further three weeks), or one of two placebo control groups who received saline in the same pattern as the HIGH (HIGH-PLACEBO, n = 4) or COMB (COMB-PLACEBO, n = 4) groups.

Software thresholds alter the bias of actigraphy for monitoring sleep in team-sport athletes.

Objectives: Actical actigraphy is commonly used to monitor athlete sleep. The proprietary software, called Actiware, processes data with three different sleep-wake thresholds (Low, Medium or High), but there is no standardisation regarding their use. The purpose of this study was to examine validity and bias of the sleep-wake thresholds for processing Actical sleep data in team sport athletes.

Bayesian Estimation of Small Effects in Exercise and Sports Science.

The aim of this paper is to provide a Bayesian formulation of the so-called magnitude-based inference approach to quantifying and interpreting effects, and in a case study example provide accurate probabilistic statements that correspond to the intended magnitude-based inferences. The model is described in the context of a published small-scale athlete study which employed a magnitude-based inference approach to compare the effect of two altitude training regimens (live high-train low (LHTL), and intermittent hypoxic exposure (IHE)) on running performance and blood measurements of elite triathletes. The posterior distributions, and corresponding point and interval estimates, for the parameters and associated effects and comparisons of interest, were estimated using Markov chain Monte Carlo simulations.

Ventilatory acclimatisation is beneficial for high-intensity exercise at altitude in elite cyclists.

Aim: The aim of this study was to examine the relationship between ventilatory adaptation and performance during altitude training at 2700 m.

Methods: Seven elite cyclists (age: 21.2 ± 1.

Effect of repeat-sprint training in hypoxia on post-exercise interleukin-6 and F2-isoprostanes.

This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5 s cycling sprints in simulated altitude (3000 m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60 min post-exercise.

Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia.

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.night(-1) at a simulated altitude of 3000 m using hypoxic tents; n = 8).

Impact of Altitude on Power Output during Cycling Stage Racing.

Purpose: The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour.

Methods: Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude.

No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability.

To assess the impact of 'top-up' normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.

A Combination of Amino Acids and Caffeine Enhances Sprint Running Capacity in a Hot, Hypoxic Environment.

Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport-specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions.

Within-subject haemoglobin variation in elite athletes: a longitudinal investigation of 13 887 haemoglobin concentration readings.

The Athlete Biological Passport (ABP) estimates individualized reference ranges for key blood markers, such as haemoglobin concentration ([Hb]), using predetermined population mean, between- and within-subject variances. Here, we aim to reassess previously published estimates for within-subject [Hb] variance and determine whether sex-, analyzer-, sport-, or season-specific values are required. Our reference population contains 7723 male (mean ± SD, 22.