ArticlePublisher preview available

Live high - Train low guided by daily heart rate variability in elite Nordic-skiers

Authors:
Laurent Schmitt at National Ski-Nordic Centre, Premanon, France
Laurent Schmitt
  • National Ski-Nordic Centre, Premanon, France
Sarah Jean Willis at University of Denver
Sarah Jean Willis
Anthony Fardel at University of Lausanne
Anthony Fardel
Nicolas Coulmy at French Ski Federation, France, Annecy
Nicolas Coulmy
  • French Ski Federation, France, Annecy
Show all 5 authorsHide
Read publisher preview
Download citation
To read the full-text of this research, you can request a copy directly from the authors.

Abstract and Figures

Purpose: To analyze if live high-train low (LHTL) effectiveness is improved when daily training is guided by heart rate variability (HRV). Methods: Twenty-four elite Nordic skiers took part in a 15-day LHTL study and were randomized into a HRV-guided training hypoxic group (H-HRV, n = 9, sleeping in normobaric hypoxia, FiO2 = 15.0%) and two predefined training groups sleeping either in hypoxia (H, n = 9, FiO2 = 15.0%) or normoxia (N, n = 6). HRV and training loads (TL) were recorded daily. Prior (Pre), one (Post-1), and 21 days (Post-21) following LHTL, athletes performed a 10-km roller-ski test, and a treadmill test for determination of [Formula: see text] was performed at Pre and Post-1. Results: Some HRV parameters measured in supine position were different between H-HRV and H: low and high (HF) frequency power in absolute (ms2) (16.0 ± 35.1 vs. 137.0 ± 54.9%, p = 0.05) and normalized units (- 3.8 ± 10.1 vs. 53.0 ± 19.5%, p = 0.02), HF(nu) (6.3 ± 6.8 vs. - 13.7 ± 8.0%, p = 0.03) as well as heart rate (3.7 ± 6.3 vs. 12.3 ± 4.1%, p = 0.008). At Post-1, [Formula: see text] was improved in H-HRV and H (3.8 ± 3.1%; p = 0.02 vs. 3.0 ± 4.4%; p = 0.08) but not in N (0.9 ± 5.1%; p = 0.7). Only H-HRV improved the roller-ski performance at Post-21 (- 2.7 ± 3.6%, p = 0.05). Conclusion: The daily individualization of TL reduced the decrease in autonomic nervous system parasympathetic activity commonly associated with LHTL. The improved performance and oxygen consumption in the two LHTL groups confirm the effectiveness of LHTL even in elite endurance athletes.
Figures - available from: European Journal of Applied Physiology
This content is subject to copyright. Terms and conditions apply.
A preview of this full-text is provided by Springer Nature.
Learn more
Content available from European Journal of Applied Physiology
This content is subject to copyright. Terms and conditions apply.
Vol.:(0123456789)
1 3
European Journal of Applied Physiology (2018) 118:419–428
https://doi.org/10.1007/s00421-017-3784-9
ORIGINAL ARTICLE
Live high–train low guided bydaily heart rate variability inelite
Nordic-skiers
LaurentSchmitt1,2· SarahJ.Willis2· AnthonyFardel2· NicolasCoulmy3· GregoireP.Millet2
Received: 8 September 2017 / Accepted: 5 December 2017 / Published online: 15 December 2017
© Springer-Verlag GmbH Germany, part of Springer Nature 2017
Abstract
Purpose To analyze if live high–train low (LHTL) effectiveness is improved when daily training is guided by heart rate
variability (HRV).
Methods Twenty-four elite Nordic skiers took part in a 15-day LHTL study and were randomized into a HRV-guided training
hypoxic group (H-HRV, n = 9, sleeping in normobaric hypoxia, FiO2 = 15.0%) and two predefined training groups sleeping
either in hypoxia (H, n = 9, FiO2 = 15.0%) or normoxia (N, n = 6). HRV and training loads (TL) were recorded daily. Prior
(Pre), one (Post-1), and 21 days (Post-21) following LHTL, athletes performed a 10-km roller-ski test, and a treadmill test
for determination of
V
O
2max
was performed at Pre and Post-1.
Results Some HRV parameters measured in supine position were different between H-HRV and H: low and high (HF) fre-
quency power in absolute (ms2) (16.0 ± 35.1 vs. 137.0 ± 54.9%, p = 0.05) and normalized units (− 3.8 ± 10.1 vs. 53.0 ± 19.5%,
p = 0.02), HF(nu) (6.3 ± 6.8 vs. − 13.7 ± 8.0%, p = 0.03) as well as heart rate (3.7 ± 6.3 vs. 12.3 ± 4.1%, p = 0.008). At Post-1,
V
O
2max
was improved in H-HRV and H (3.8 ± 3.1%; p = 0.02 vs. 3.0 ± 4.4%; p = 0.08) but not in N (0.9 ± 5.1%; p = 0.7). Only
H-HRV improved the roller-ski performance at Post-21 (− 2.7 ± 3.6%, p = 0.05).
Conclusion The daily individualization of TL reduced the decrease in autonomic nervous system parasympathetic activity
commonly associated with LHTL. The improved performance and oxygen consumption in the two LHTL groups confirm
the effectiveness of LHTL even in elite endurance athletes.
Keywords Hypoxia· HRV· Endurance performance
Abbreviations
ANOVA Analysis of variance
FFT Fast Fourier transform
FiO2 Inspired fraction of oxygen
H Hypoxic
HF High-frequency power
HFnu High-frequency power in normalized units
Hbmass Hemoglobin mass
HR Heart rate
HRV Heart rate variability
LF Low-frequency power
LFnu Low-frequency power in normalized units
LHTL Live high–train low
N Normoxic
PiO2 Partial pressure of inspired oxygen
QSFMS Questionnaire of the French Society of Sports
Medicine
SpO2 Pulse oxygen saturation
TL Training load
VE
/
VCO2
Ventilatory equivalent of carbon dioxide
VE
/
VO2
Ventilatory equivalent of oxygen
VO2max
Maximal oxygen consumption
VT1 First ventilatory threshold
VT2 Second ventilatory threshold
Communicated by Massimo Pagani.
* Laurent Schmitt
laurent.schmitt@ensm.sports.gouv.fr
1 National School ofMountain Sports/National Ski-Nordic
Centre, 1848 route des Pessettes, 39220Premanon, France
2 ISSUL, Institute ofSport Sciences, Faculty ofBiology
andMedicine, University ofLausanne, Lausanne,
Switzerland
3 French Ski Federation, 74000Annecy, France
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... HRV is a non-invasive, valid and reliable measure of the balance of the sympathetic and parasympathetic branch of the autonomic nervous system (ANS) [14]. Numerous studies have identified it as a variable which is sensitive to the effect of training, showing the response to exercise and fatigue levels [13,15] and it has been used to guide training on a daily basis in sports, such as running [16][17][18], cross-country skiing [19], cycling [20,21] or in untrained healthy women [22]. The main findings of these previous studies are that greater increases in physical fitness were obtained for day-to-day models compared to traditional ones [16,19,20] or they showed similar improvements, but with a lower dose of physical exercise by day-to-day models [17,18,21], which meant a time optimisation to achieve the desired improvements. ...
... Numerous studies have identified it as a variable which is sensitive to the effect of training, showing the response to exercise and fatigue levels [13,15] and it has been used to guide training on a daily basis in sports, such as running [16][17][18], cross-country skiing [19], cycling [20,21] or in untrained healthy women [22]. The main findings of these previous studies are that greater increases in physical fitness were obtained for day-to-day models compared to traditional ones [16,19,20] or they showed similar improvements, but with a lower dose of physical exercise by day-to-day models [17,18,21], which meant a time optimisation to achieve the desired improvements. The premise of these day-to-day models is that training is modulated according to the organism's status (based on HRV), performing vigorous physical exercise when the individual is prepared (i.e., normal values in HRV) and, conversely, performing light physical exercise or resting when there is a sign of excessive fatigue or stress (i.e., alteration in HRV values). ...
... They were expressed in Cohen's d units and were interpreted as trivial (<0. 19), small (0.20-0.49), moderate (0.50-0.79) and large (>0.80), and the effect sizes (ES) were shown with a CI of 95% between groups [42]. Pearson correlation coefficient (r) was calculated to assess the strength of association between HRV measurements with the different devices and the duration of the measurement in 1 min and 5 min and it was interpreted as trivial (<0.09), small (0.10-0.29), moderate (0.30-0.49), high (0.50-0.69), very high (0.70-0.89), and almost perfect (>0.90) [43]. ...
Designing an App to Promote Physical Exercise in Sedentary People Using a Day-to-Day Algorithm to Ensure a Healthy Self-Programmed Exercise Training
Article
Full-text available
Heart rate variability (HRV) has allowed the implementation of a methodology for daily decision making called day-to-day training, which allows data to be recorded by anyone with a smartphone. The purpose of the present work was to evaluate the validity and reliability of HRV measurements with a new mobile app (Selftraining UMH) in two resting conditions. Twenty healthy people (10 male and 10 female) were measured at rest in supine and seated positions with an electrocardiogram and an application for smartphones at the same time (Selftraining UMH) using recordings obtained through an already validated chest-worn heart rate monitor (Polar H10). The Selftraining UMH app showed no significant differences compared to an electrocardiogram, neither in supine nor in sitting position (p > 0.05) and they presented almost perfect correlation levels (r ≥ 0.99). Furthermore, no significant differences were found between ultra-short (1-min) and short (5-min) length measurements. The intraclass correlation coefficient showed excellent reliability (>0.90) and the standard error of measurement remained below 5%. The Selftraining UMH smartphone app connected via Bluetooth to the Polar H10 chest strap can be used to register daily HRV recordings in healthy sedentary people.
View
... The LHTL method of altitude training has previously been used across a range of endurance based disciplines including distance running, swimming, cycling, triathlons, and in team-sport settings such as Australian rules football, soccer, and hockey (Sinex and Chapman, 2015;McLean et al., 2013). Among such athletes TT performance (Levine and Stray-Gundersen, 1997a), increased VO 2MAX (Schmitt et al., 2018), and heightened mean PPO (Bonetti et al., 2006) may be realised after completing an LHTL intervention. Previously, (Robertson et al., 2010b) have suggested for such benefits, an intervention should comprise 2-3 weeks of exposure with >12 h⋅d-1, which corresponds to a hypoxic dosage of 1260 km h. ...
... Studies (Dehnert et al., 2002;Robertson et al., 2010b;Rusko et al., 1999;Schmitt et al., 2018;Stray-Gundersen et al., 2001;Witkowski et al., 2001) have shown significant benefits for VO 2MAX utilising LHTL training protocols. The intervention from these studies ranged from 356 to 1884 km h. ...
Physiological and performance effects of live high train low altitude training for elite endurance athletes: A narrative review
Article
Full-text available
  • Nov 2023
Altitude training has become an important training application for athletes due its potential for altering physiology and enhancing performance. This practice is commonly used by athletes, with a popular choice being the live high - train low approach. This model recommends that athletes live at high altitude (1250–3000 m), but train at low altitude or sea-level (0–1200 m). Exposure to altitude often leads to hypoxic stress and in turn stimulates changes in total haemoglobin mass, erythropoietin, and soluble transferrin receptors, which alter further underlying physiology. Through enhanced physiology, improved exercise performance may arise through enhancement of the oxygen transport system which is important for endurance events. Previous investigations into the effects of altitude training on exercise performance have been completed in a range of contexts, including running, cycling, swimming, and triathlon. Often following a LHTL altitude intervention, athletes realise improvements in maximal oxygen consumption capacity, time trial performance and peak power outputs. Although heterogeneity exists among LHTL methodologies, i.e., exposure durations and altitude ranges, we synthesised this data into kilometre hours, and found that the most common hypoxic doses used in LHTL interventions ranged from ∼578–687 km h. As this narrative review demonstrates, there are potential advantages to using altitude training to enhance physiology and improve performance for endurance athletes.
View
... In the HRV-G, the relative changes in submaximal and maximal aerobic power were 24.8% for WLT, 18.1% for WOBLA, and 15.0% for Wmax. In the earlier studies, the relative changes in aerobic power induced by HRVguided training ranged from 2.8 to 37.6% for aerobic power at the LT level (Javaloyes et al., 2019;Javaloyes et al., 2020;Nuuttila et al., 2017;Vesterinen et al., 2016), from 2.6 to 22.9% for aerobic power at the OBLA level (Javaloyes et al., 2019;Javaloyes et al., 2020;Nuuttila et al., 2017;Schmitt et al., 2018;Vesterinen et al., 2016), and from 5.1 to 10.4% for maximal aerobic power (Javaloyes et al., 2019;Javaloyes et al., 2020;Kiviniemi et al., 2010). The submaximal aerobic power obtained in this study was similar; however, the maximal aerobic power was greater than that reported in previous studies. ...
Heart rate variability-guided aerobic training without moderate-intensity enhances submaximal and maximal aerobic power with less training load
Article
Full-text available
  • Dec 2024
This study aims to clarify the effects of heart rate variability (HRV)-guided aerobic training on submaximal and maximal aerobic power. Twelve active men participated in a 5-week intervention and were divided into two groups: a block periodization training group (BP, n = 6) and a HRV-guided training group (HRV-G, n = 6). All participants underwent the same aerobic training during week one. In weeks 2–5, the training load for the HRV-G was adjusted based on the HRV of an individual on waking. The BP underwent 2 weeks of overload training followed by 2 weeks of taper training. To determine the submaximal and maximal aerobic powers, an incremental load test was performed at baseline and once a week. The internal load during the training sessions was derived from the heart rate. The monotony and strain were calculated from the internal load. TRIMP and the strain were lower in the HRV-G than BP. The HRV-G had a greater relative distribution of time spent at low-intensity and a lower relative distribution of time spent at high-intensity than BP. The change in the maximal and submaximal aerobic power was greater in the HRV than in BP. The current findings indicate that combined low- and high-intensity HRV-guided training enhance increases the submaximal and maximal aerobic power, regardless lower training load than BP.
View
... HRV-guided programming for endurance athletes is associated with significant increases in maximum running velocity, VO2 max, VO2 at the first and second ventilatory thresholds, peak power output, HRV, and serum testosterone levels compared to predefined or block periodized groups [18,[65][66][67]. This association has been identified in running [18,62], cross-country skiing [68], and cycling [66]. It is likely that HRV-guided training has utility in elite or highly trained endurance athletes [69]. ...
Heart Rate Variability Applications in Strength and Conditioning: A Narrative Review
Article
Full-text available
  • May 2024
Heart rate variability (HRV) is defined as the fluctuation of time intervals between adjacent heartbeats and is commonly used as a surrogate measure of autonomic function. HRV has become an increasingly measured variable by wearable technology for use in fitness and sport applications. However, with its increased use, a gap has arisen between the research and the application of this technology in strength and conditioning. The goal of this narrative literature review is to discuss current evidence and propose preliminary guidelines regarding the application of HRV in strength and conditioning. A literature review was conducted searching for HRV and strength and conditioning, aiming to focus on studies with time-domain measurements. Studies suggest that HRV is a helpful metric to assess training status, adaptability, and recovery after a training program. Although reduced HRV may be a sign of overreaching and/or overtraining syndrome, it may not be a sensitive marker in aerobic-trained athletes and therefore has different utilities for different athletic populations. There is likely utility to HRV-guided programming compared to predefined programming in several types of training. Evidence-based preliminary guidelines for the application of HRV in strength and conditioning are discussed. This is an evolving area of research, and more data are needed to evaluate the best practices for applying HRV in strength and conditioning.
View
... HRV can therefore help to identify the relationship between external and internal loads.Schmitt, Willis, et al. (2018) subjected elite XCS and Nordic combined athletes to a 15-day HRV guided training in live hightrain low conditions to decide on daily individualized adjustments of the training load. The guided and nonguided groups improved their VO 2 max by 3.8% (p = 0.02) and 3% (p = 0.08), respectively, with only the guided group improving their rolle ...
The puzzle of monitoring training load in winter sports -A hard nut to crack?
Article
Full-text available
  • May 2024
Elite winter sports have become increasingly professionalized and commercialized , often accompanied by congested competition schedules. This has brought the topic of load management, i.e., planning, monitoring, and adaptation , enormous attention in the scientific community. In this review, we summarize the general knowledge from various sports about training load and its effects on injuries and illnesses. After outlining the fundamentals of load monitoring, we present common monitoring tools, i.e., neuromuscular performance tests, heart rate measures, blood-based biomarkers, and questionnaires and discuss their potentials and pitfalls in application. Studies have identified training load-related variables, but also other factors such as travelling, previous injuries, or age contributing to the occurrence of illness and injury. Based on our findings, the use of monitoring tools must be context specific and long-term, considering statistical aspects as well. Promising study designs and future perspectives are finally highlighted, with the general conclusion that there is still a clear need for research on this topic in general and in the field of winter sports in particular.
View
... Previous studies evidenced that monitoring HRV during training resulted in performance improvements because the training load could be adapted on a daily basis to what the athletes could bear (Schmitt et al., 2018). Moreover, it was previously proposed that the analysis of the day-to-day variation in HRV parameters would be valuable for diagnosing non-functional overreaching (Plews et al., 2012). ...
Daily cardiac autonomic responses during the Tour de France in a male professional cyclist
Article
Full-text available
  • Jan 2024
Background Heart rate variability (HRV) is a common means of monitoring responses to training, yet in professional cycling, one may question its usefulness, particularly during multi-day competitions such as Grand Tours. Objectives This study aims to report and analyze HRV responses in a male professional cyclist over a season, including the Tour de France. Methods A professional cyclist recorded resting and exercise inter-beat intervals during 5 months, comprising a training period with two altitude sojourns and two competition blocks, including the Tour de France. Resting recordings lasted 5 min in the supine position and were used for computation of mean heart rate (HR), root mean square of the successive differences (RMSSDs), and power in the low- and high-frequency bands (LF and HF, respectively). Training load quantification was based on recorded HR during exercise and expressed as training impulses (TRIMPSs). Results LF (3,319 ± 2,819 vs. 1,097 ± 1,657 ms²), HF (3,590 ± 1858 vs. 1,267 ± 1,683 ms²), and RMSSD (96 ± 26 vs. 46 ± 30 ms) were higher and HR (47 ± 4 vs. 54 ± 2 bpm) was lower during the training period when compared to the two competition blocks. The coefficient of variation (CV) was significantly lower during the training period than during the two competition blocks for RMSSD (26 vs. 72%), LF (85 vs. 160%), and HF (58 vs. 141%). Discussion The present study confirms that monitoring daily HRV responses during training periods is valuable in professional cycling, but questions its usefulness during the Tour de France. Moreover, the previous suggestion that CV in RMSSD would help to predict poor performance was not confirmed in a professional cyclist.
View
... continuity (Brocherie et al., 2017;Mujika et al., 2018). Thus, to minimize this potential risk and maximize the benefits of AT, an effective health and load monitoring system should be developed (Sperlich et al., 2016;Schmitt et al., 2018;Mujika et al., 2019) and adequate nutritional support should be provided (Govus et al., 2015;Stellingwerff et al., 2019). Currently, the investigated lower limit of the hypoxic dose of HH is lower than the previous study results (Millet et al., 2010). ...
Optimal type and dose of hypoxic training for improving maximal aerobic capacity in athletes: a systematic review and Bayesian model-based network meta-analysis
Article
Full-text available
  • Sep 2023
Objective: This study aimed to compare and rank the effect of hypoxic practices on maximum oxygen consumption (VO2max) in athletes and determine the hypoxic dose-response correlation using network meta-analysis. Methods: The Web of Science, PubMed, EMBASE, and EBSCO databases were systematically search for randomized controlled trials on the effect of hypoxc interventions on the VO2max of athletes published from inception until 21 February 2023. Studies that used live-high train-high (LHTH), live-high train-low (LHTL), live-high, train-high/low (HHL), intermittent hypoxic training (IHT), and intermittent hypoxic exposure (IHE) interventions were primarily included. LHTL was further defined according to the type of hypoxic environment (natural and simulated) and the altitude of the training site (low altitude and sea level). A meta-analysis was conducted to determine the standardized mean difference between the effects of various hypoxic interventions on VO2max and dose-response correlation. Furthermore, the hypoxic dosage of the different interventions were coordinated using the “kilometer hour” model. Results: From 2,072 originally identified titles, 59 studies were finally included in this study. After data pooling, LHTL, LHTH, and IHT outperformed normoxic training in improving the VO2max of athletes. According to the P-scores, LHTL combined with low altitude training was the most effective intervention for improving VO2max (natural: 0.92 and simulated: 0.86) and was better than LHTL combined with sea level training (0.56). A reasonable hypoxic dose range for LHTH (470–1,130 kmh) and HL (500–1,415 kmh) was reported with an inverted U-shaped curve relationship. Conclusion: Different types of hypoxic training compared with normoxic training serve as significant approaches for improving aerobic capacity in athletes. Regardless of the type of hypoxic training and the residential condition, LHTL with low altitude training was the most effective intervention. The characteristics of the dose-effect correlation of LHTH and LHTL may be associated with the negative effects of chronic hypoxia.
View
... Also, Bertisch et al. (90) reported that baroreflex sensitivity was ∼20% lower in patients with sleep disorders compared to healthy controls. (ii) HRV indices measured from short (15 min) (91) or longer (24h-ECG holter) ECG recordings (81), using HRV analysis software [e.g., (92)]. The main time domain indices are the standard deviation of NN intervals, the root mean square of successive RR interval differences (RMSSD) and percentage of successive RR intervals that differ by more than 50 ms (pNN50) ( Table 1). ...
Measuring objective fatigability and autonomic dysfunction in clinical populations: How and why?
Article
Full-text available
  • Mar 2023
Fatigue is a major symptom in many diseases, often among the most common and severe ones and may last for an extremely long period. Chronic fatigue impacts quality of life, reduces the capacity to perform activities of daily living, and has socioeconomical consequences such as impairing return to work. Despite the high prevalence and deleterious consequences of fatigue, little is known about its etiology. Numerous causes have been proposed to explain chronic fatigue. They encompass psychosocial and behavioral aspects (e.g., sleep disorders) and biological (e.g., inflammation), hematological (e.g., anemia) as well as physiological origins. Among the potential causes of chronic fatigue is the role of altered acute fatigue resistance, i.e. an increased fatigability for a given exercise, that is related to physical deconditioning. For instance, we and others have recently evidenced that relationships between chronic fatigue and increased objective fatigability, defined as an abnormal deterioration of functional capacity (maximal force or power), provided objective fatigability is appropriately measured. Indeed, in most studies in the field of chronic diseases, objective fatigability is measured during single-joint, isometric exercises. While those studies are valuable from a fundamental science point of view, they do not allow to test the patients in ecological situations when the purpose is to search for a link with chronic fatigue. As a complementary measure to the evaluation of neuromuscular function (i.e., fatigability), studying the dysfunction of the autonomic nervous system (ANS) is also of great interest in the context of fatigue. The challenge of evaluating objective fatigability and ANS dysfunction appropriately (i.e.,. how?) will be discussed in the first part of the present article. New tools recently developed to measure objective fatigability and muscle function will be presented. In the second part of the paper, we will discuss the interest of measuring objective fatigability and ANS (i.e. why?). Despite the beneficial effects of physical activity in attenuating chronic fatigue have been demonstrated, a better evaluation of fatigue etiology will allow to personalize the training intervention. We believe this is key in order to account for the complex, multifactorial nature of chronic fatigue.
View
Assessing the clinical reliability of short-term heart rate variability: insights from controlled dual-environment and dual-position measurements
Article
Full-text available
  • Feb 2025
Heart rate variability (HRV) is a widely recognized biomarker for autonomic nervous system regulation, applicable in clinical and athletic settings to monitor health and recovery. Despite its extensive use, HRV measurement reliability is influenced by numerous factors, necessitating controlled conditions for accurate assessments. This study investigates the reliability of short-term HRV measurements in various settings and positions, aiming to establish consistent protocols for HRV monitoring and interpretation. We assessed morning HRV in 34 healthy, physically active adults across supine and standing positions, at home and in the laboratory, over a 24-hour period. Environment significantly impacted standing HRV. Home measurements exhibited slightly lower variance compared to lab settings, underscoring the importance of environment control. Our findings confirm the high reliability of HRV measurements, indicating their robustness in capturing autonomic changes, provided a rigorous methodology is employed. Here we show that effective and reliable HRV assessment is possible across various conditions, contingent upon strict management of confounding factors. This research supports the utility of HRV as a non-invasive diagnostic tool, emphasizing its importance in health management and potential in broadening applications to diverse populations. Future studies are encouraged to expand these assessments to include varied demographic and clinical profiles, enhancing HRV integration into routine health evaluations.
View
View
Same Performance Changes after Live High-Train Low in Normobaric vs. Hypobaric Hypoxia
Article
Full-text available
  • Apr 2016
Purpose: We investigated the changes in physiological and performance parameters after a Live High-Train Low (LHTL) altitude camp in normobaric (NH) or hypobaric hypoxia (HH) to reproduce the actual training practices of endurance athletes using a crossover-designed study. Methods: Well-trained triathletes (n = 16) were split into two groups and completed two 18-day LTHL camps during which they trained at 1100–1200 m and lived at 2250 m (PiO2 = 111.9 ± 0.6 vs. 111.6 ± 0.6 mmHg) under NH (hypoxic chamber; FiO2 18.05 ± 0.03%) or HH (real altitude; barometric pressure 580.2 ± 2.9 mmHg) conditions. The subjects completed the NH and HH camps with a 1-year washout period. Measurements and protocol were identical for both phases of the crossover study. Oxygen saturation (SpO2) was constantly recorded nightly. PiO2 and training loads were matched daily. Blood samples and VO2max were measured before (Pre-) and 1 day after (Post-1) LHTL. A 3-km running-test was performed near sea level before and 1, 7, and 21 days after training camps. Results: Total hypoxic exposure was lower for NH than for HH during LHTL (230 vs. 310 h; P < 0.001). Nocturnal SpO2 was higher in NH than in HH (92.4 ± 1.2 vs. 91.3 ± 1.0%, P < 0.001). VO2max increased to the same extent for NH and HH (4.9 ± 5.6 vs. 3.2 ± 5.1%). No difference was found in hematological parameters. The 3-km run time was significantly faster in both conditions 21 days after LHTL (4.5 ± 5.0 vs. 6.2 ± 6.4% for NH and HH), and no difference between conditions was found at any time. Conclusion: Increases in VO2max and performance enhancement were similar between NH and HH conditions.
View
Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-Analysis
Article
Full-text available
  • Nov 2013
Objective To characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure. Methods This meta-analysis uses raw data from 17 studies that used carbon monoxide rebreathing to determine Hbmass prealtitude, during altitude and postaltitude. Seven studies were classic altitude training, eight were live high train low (LHTL) and two mixed classic and LHTL. Separate linear-mixed models were fitted to the data from the 17 studies and the resultant estimates of the effects of altitude used in a random effects meta-analysis to obtain an overall estimate of the effect of altitude, with separate analyses during altitude and postaltitude. In addition, within-subject differences from the prealtitude phase for altitude participant and all the data on control participants were used to estimate the analytical SD. The ‘true’ between-subject response to altitude was estimated from the within-subject differences on altitude participants, between the prealtitude and during-altitude phases, together with the estimated analytical SD. Results During-altitude Hbmass was estimated to increase by ∼1.1%/100 h for LHTL and classic altitude. Postaltitude Hbmass was estimated to be 3.3% higher than prealtitude values for up to 20 days. The within-subject SD was constant at ∼2% for up to 7 days between observations, indicative of analytical error. A 95% prediction interval for the ‘true’ response of an athlete exposed to 300 h of altitude was estimated to be 1.1–6%. Conclusions Camps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit.
View
Year-To-Year variability in haemoglobin mass response to two altitude training camps
Article
Full-text available
  • Dec 2013
Aim To quantify the year-to-year variability of altitude-induced changes in haemoglobin mass (Hbmass) in elite team-sport athletes. Methods 12 Australian-Footballers completed a 19-day (ALT1) and 18-day (ALT2) moderate altitude (∼2100 m), training camp separated by 12 months. An additional 20 participants completed only one of the two training camps (ALT1 additional n=9, ALT2 additional n=11). Total Hbmass was assessed using carbon monoxide rebreathing before (PRE), after (POST1) and 4 weeks after each camp. The typical error of Hbmass for the pooled data of all 32 participants was 2.6%. A contemporary statistics analysis was used with the smallest worthwhile change set to 2% for Hbmass. Results POST1 Hbmass was very likely increased in ALT1 (3.6±1.6%, n=19; mean±∼90 CL) as well as ALT2 (4.4±1.3%, n=23) with an individual responsiveness of 1.3% and 2.2%, respectively. There was a small correlation between ALT1 and ALT2 (R=0.21, p=0.59) for a change in Hbmass, but a moderately inverse relationship between the change in Hbmass and initial relative Hbmass (g/kg (R=−0.51, p=0.04)). Conclusions Two preseason moderate altitude camps 1 year apart yielded a similar (4%) mean increase in Hbmass of elite footballers, with an individual responsiveness of approximately half the group mean effect, indicating that most players gained benefit. Nevertheless, the same individuals generally did not change their Hbmass consistently from year to year. Thus, a ‘responder’ or ‘non-responder’ to altitude for Hbmass does not appear to be a fixed trait.
View
Does Overtraining Exist?
Article
Full-text available
  • Dec 2004
Athletes experience minor fatigue and acute reductions in performance as a consequence of the normal training process. When the balance between training stress and recovery is disproportionate, it is thought that overreaching and possibly overtraining may develop. However, the majority of research that has been conducted in this area has investigated overreached and not overtrained athletes. Overreaching occurs as a result of intensified training and is often considered a normal outcome for elite athletes due to the relatively short time needed for recovery (approximately 2 weeks) and the possibility of a supercompensatory effect. As the time needed to recover from the overtraining syndrome is considered to be much longer (months to years), it may not be appropriate to compare the two states. It is presently not possible to discern acute fatigue and decreased performance experienced from isolated training sessions, from the states of overreaching and overtraining. This is partially the result of a lack of diagnostic tools, variability of results of research studies, a lack of well controlled studies and individual responses to training. The general lack of research in the area in combination with very few well controlled investigations means that it is very difficult to gain insight into the incidence, markers and possible causes of overtraining. There is currently no evidence aside from anecdotal information to suggest that overreaching precedes overtraining and that symptoms of overtraining are more severe than overreaching. It is indeed possible that the two states show different defining characteristics and the overtraining continuum may be an oversimplification. Critical analysis of relevant research suggests that overreaching and overtraining investigations should be interpreted with caution before recommendations for markers of overreaching and overtraining can be proposed. Systematically controlled and monitored studies are needed to determine if overtraining is distinguishable from overreaching, what the best indicators of these states are and the underlying mechanisms that cause fatigue and performance decrements. The available scientific and anecdotal evidence supports the existence of the overtraining syndrome; however, more research is required to state with certainty that the syndrome exists.
View
“Living high-training low” altitude training improves sea level performance in male and female elite runners
Article
  • Sep 2001
Acclimatization to moderate high altitude accompanied by training at low altitude (living high-training low) has been shown to improve sea level endurance performance in accomplished, but not elite, runners. Whether elite athletes, who may be closer to the maximal structural and functional adaptive capacity of the respiratory (i.e., oxygen transport from environment to mitochondria) system, may achieve similar performance gains is unclear. To answer this question, we studied 14 elite men and 8 elite women before and after 27 days of living at 2,500 m while performing high-intensity training at 1,250 m. The altitude sojourn began 1 wk after the USA Track and Field National Championships, when the athletes were close to their season's fitness peak. Sea level 3,000-m time trial performance was significantly improved by 1.1% (95% confidence limits 0.3–1.9%). One-third of the athletes achieved personal best times for the distance after the altitude training camp. The improvement in running performance was accompanied by a 3% improvement in maximal oxygen uptake (72.1 ± 1.5 to 74.4 ± 1.5 ml · kg ⁻¹ · min ⁻¹ ). Circulating erythropoietin levels were near double initial sea level values 20 h after ascent (8.5 ± 0.5 to 16.2 ± 1.0 IU/ml). Soluble transferrin receptor levels were significantly elevated on the 19th day at altitude, confirming a stimulation of erythropoiesis (2.1 ± 0.7 to 2.5 ± 0.6 μg/ml). Hb concentration measured at sea level increased 1 g/dl over the course of the camp (13.3 ± 0.2 to 14.3 ± 0.2 g/dl). We conclude that 4 wk of acclimatization to moderate altitude, accompanied by high-intensity training at low altitude, improves sea level endurance performance even in elite runners. Both the mechanism and magnitude of the effect appear similar to that observed in less accomplished runners, even for athletes who may have achieved near maximal oxygen transport capacity for humans.
View
View
View
Similar Hemoglobin Mass Response in Hypobaric and Normobaric Hypoxia in Athletes
Article
  • Apr 2016
PURPOSE: To compare hemoglobin mass (Hbmass) 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. Hbmass 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). Running (3-km run) and cycling (incremental cycling test) performances were measured pre and post. RESULTS: Hbmass increased similar in HH (+4.4%, P < 0.001 at day 13; +4.5%, P < 0.001 at day 18) and NH (+4.1%, P < 0.001) compared with CON (+1.9%, P = 0.08). There was a wide variability in individual Hbmass responses in HH (-0.1% to +10.6%) and NH (-1.4% to +7.7%). Postrunning time decreased in HH (-3.9%, P < 0.001), NH (-3.3%, P < 0.001), and CON (-2.1%, P = 0.03), whereas cycling performance changed nonsignificantly in HH and NH (+2.4%, P > 0.08) and remained unchanged in CON (+0.2%, P = 0.89). CONCLUSION: HH and NH evoked similar Hbmass increases for the same hypoxic dose and after 18-d LHTL. The wide variability in individual Hbmass responses in HH and NH emphasizes the importance of individual Hbmass evaluation of altitude training.
View
Typology of “Fatigue” by Heart Rate Variability Analysis in Elite Nordic-skiers
Article
  • Aug 2015
  • INT J SPORTS MED
This study investigated changes in heart rate variability (HRV) in elite Nordic-skiers to characterize different types of "fatigue" in 27 men and 30 women surveyed from 2004 to 2008. R-R intervals were recorded at rest during 8 min supine (SU) followed by 7 min standing (ST). HRV parameters analysed were powers of low (LF), high (HF) frequencies, (LF+HF) (ms(2)) and heart rate (HR, bpm). In the 1 063 HRV tests performed, 172 corresponded to a "fatigue" state and the first were considered for analysis. 4 types of "fatigue" (F) were identified: 1. F(HF(-)LF(-))SU_ST for 42 tests: decrease in LFSU (- 46%), HFSU (- 70%), LFST (- 43%), HFST (- 53%) and increase in HRSU (+ 15%), HRST (+ 14%). 2. F(LF(+) SULF(-) ST) for 8 tests: increase in LFSU (+ 190%) decrease in LFST (- 84%) and increase in HRST (+ 21%). 3. F(HF(-) SUHF(+) ST) for 6 tests: decrease in HFSU (- 72%) and increase in HFST (+ 501%). 4. F(HF(+) SU) for only 1 test with an increase in HFSU (+ 2161%) and decrease in HRSU (- 15%). Supine and standing HRV patterns were independently modified by "fatigue". 4 "fatigue"-shifted HRV patterns were statistically sorted according to differently paired changes in the 2 postures. This characterization might be useful for further understanding autonomic rearrangements in different "fatigue" conditions. © Georg Thieme Verlag KG Stuttgart · New York.
View
“Live High–Train Low and High” Hypoxic Training Improves Team-Sport Performance
Article
  • Feb 2015
  • MED SCI SPORT EXER
To investigate physical performance and hematological changes in 32 elite male team-sport players after 14 days of 'live high-train low' (LHTL) in normobaric hypoxia (≥14 h.day at 2800-3000 m) combined with repeated-sprint training (6 sessions of 4 sets of 5 x 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 to controlled 'live low-train low' (LLTL; n = 9). Prior to (Pre-), immediately (Post-1) and 3 weeks (Post-2) after the intervention, hemoglobin mass (Hbmass) was measured in duplicate (optimized carbon monoxide rebreathing method) and vertical jump, repeated-sprint (8 x 20 m - 20 s recovery) and Yo-Yo Intermittent Recovery level 2 (YYIR2) performances were tested. Both hypoxic groups increased similarly Hbmass at Post-1 and Post-2 in reference to Pre- (LHTLH: +4.0%, P<0.001 and +2.7%, P<0.01; LHTL: +3.0% and +3.0%, both P<0.001), while no change occurred in LLTL. Compared to Pre-, YYIR2 performance increased by ∼21% at Post-1 (P<0.01) and by ∼45% at Post-2 (P<0.001) with no difference between the two intervention groups (vs. no change in LLTL). From Pre- to Post-1 cumulated sprint time decreased in LHTLH (-3.6%, P<0.001) and in LHTL (-1.9%, P<0.01), but not in LLTL (-0.7%), and remained significantly reduced at Post-2 (-3.5% P<0.001) in LHTLH only. Vertical jump performance did not change. 'Live high-train low and high' hypoxic training interspersed with repeated sprints in hypoxia for 14 days (in-season) increases Hbmass, YYIR2 performance and repeated-sprint ability of elite field team-sport players with the benefits lasting for at least three weeks post-intervention.
View