In recent years, research examining the sleep of elite athletes has increased. This is predominantly due to the importance sleep has on an athlete’s psychological and physiological well-being. Despite the growing importance of sleep in athletes, the amount and quality of sleep coaches obtain has been neglected. The aim of this study was to examine the sleep of a head coach and compare it to his team. The sleep of 16 members of the Australian U/20 men’s football team (age 18.8 ± 0.9 years) and the head coach (age 55 years) was monitored using wrist activity monitors and self-report sleep diaries. Sleep was examined for 15 nights in preparation for the 2011 U/20 FIFA World Cup. The head coach went to bed earlier (23:30 h ± 65 min vs. 23:36 h ± 30 min), spent less time in bed (8.4 ± 1.3 h vs. 8.6 ± 1.0 h), obtained less sleep per night (6.4 ± 1.5 h vs. 6.6 ± 0.8 h), and woke up earlier (07:54 h ± 46 min vs. 08:12 h ± 52 min) than his team. In general, the head coach obtained less sleep than his team and slept considerably poorer the night before important games. Future investigations need to examine the extent to which sleep impairs psychological state, decision-making and overall coaching performance.

Fluctuations in ambient temperature and pressure, as well as physical jostling, may affect the stability of whole blood samples transported by air freight. The aim of this study was to characterize the stability of key blood variables during air freight and to investigate whether vibration or reduced pressure alone affected results.

This study sought to quantify the effects of reduced training, surgery and changes in body mass on haemoglobin mass (Hbmass) in athletes. Hbmass of 15 athletes (6 males, 9 females) was measured 9±6 (mean±SD) times over 162±198 days, during reduced training following injury or illness. Additionally, body mass (n=15 athletes) and episodes of altitude training (n=2), iron supplementation (n=5), or surgery (n=3) were documented. Training was recorded and compared with pre-injury levels. Analysis used linear mixed models for ln(Hbmass), with Sex, Altitude, Surgery, Iron, Training and log(Body Mass) as fixed effects, and Athlete as a fixed and random effect. Reduced training and surgery led to 2.3% (p=0.02) and 2.7% (p=0.04) decreases in Hbmass, respectively. Altitude and iron increased Hbmass by 2.4% (p=0.03) and 4.2% (p=0.05), respectively. The effect of changes in body mass on Hbmass was not statistically significant (p=0.435).The estimates for the effects of surgery and altitude on Hbmass should be confirmed by future research using a larger sample of athletes. These estimates could be used to inform the judgements of experts examining athlete biological passports, improving their interpretation of Hbmass perturbations, which athletes claim are related to injury, thereby protecting innocent athletes from unfair sanctioning.

SummaryIntroductionExtended intervals between sample collection and analyses render athlete's whole‐blood specimens collected in the field for antidoping purposes susceptible to storage degradation. The aim of this study was to characterize the stability of key blood variables under different storage durations and temperatures.MethodsWe evaluated stability of full blood count indices (plus reticulocytes) in individual tubes left undisturbed during 36, 48, 72, 96, 120, 144 and 168 h of storage at approximately 4, 6 and 12 °C. Samples were measured on a Sysmex XT‐2000i instrument.ResultsThe two key variables in the context of antidoping (haemoglobin concentration, reticulocytes) were stable for at least 168 h, except under 12 °C (stable 48 h only). Volume‐dependent variables changed in a predictable manner that enabled a nomogram to be generated to predict original values provided storage duration and temperature were known.ConclusionKey blood results can be relied upon for at least 7 days if storage temperature is kept at 4–6 °C.

Sensitivity of the Athlete Blood Passport for blood doping could be improved by including total haemoglobin mass (Hb(mass)), but this measure may be unreliable immediately following strenuous exercise. We examined the stability of Hb(mass) following ultra-endurance triathlon (3.8 km swim, 180 km bike, 42.2 km run). 26 male sub-elite triathletes, 18 Racers and 8 Controls, were tested for Hb(mass) using CO re-breathing, twice 1-5 days apart. Racers were measured before and 1-3 h after the triathlon. Controls did no vigorous exercise on either test day. Serum haptoglobin concentration and urine haemoglobin concentration were measured to assess intravascular haemolysis. There was a 3.2% (p<0.01) increase in Racers' Hb(mass) from pre-race (976 g ± 14.6%, mean ±% coefficient of variation) to post-race (1 007 g ± 13.8%), as opposed to a - 0.5% decrease in Controls (pre-race 900 g ± 13.9%, post-race 896 g ± 12.4%). Haptoglobin was - 67% (p<0.01) reduced in Racers (pre-race 0.48 g / L ± 150%, post-race 0.16 g / L ± 432%), compared to - 6% reduced in Controls (pre-race 1.08 g / L ± 37%, post-race 1.02 g / L ± 37%). Decreased serum haptoglobin concentration in Racers, which is suggestive of mild intravascular blood loss, was contrary to the apparent Hb(mass) increase post-race. Ultra-endurance triathlon racing may confound the accuracy of post-exercise Hb(mass) measures, possibly due to splenic contraction or an increased rate of CO diffusion to intramuscular myoglobin.

Haemoglobin mass (Hb(mass)) determination using CO rebreathing may assist to detect illegal blood doping practices, however variations in Hb(mass) with periods of intensive training and detraining must be quantified. This study aimed to determine the effect of a 30-day period of detraining on Hb(mass) in ultra-endurance triathletes. 9 male recreational triathletes (29-44 years) participated in the study. Hb(mass) was assessed using CO rebreathing 30 days and 10 days before an ultra-endurance triathlon and after similar to 10, 20 and 30 days of detraining following the race. (V)over dotO(2max) was assessed 10 days before the race and also after the 30-day detraining period, which consisted of an 87% reduction in training hours. After 30-days of detraining there was a 3.1% decrease in mean Hb(mass) from 868 +/- 99 to 840 +/- 94 g, (p = 0.03), and a 4.7% decrease in mean (V)over dotO(2max) from 4.83 +/- 0.29 to 4.61 +/- 0.41 L/min as well as a 2.8% increase of body mass from 75.1 +/- 6.4 to 77.1 +/- 6.1 kg and a 28% increase in skinfold total from 43.9 +/- 14.2 to 55.1 +/- 14.0 mm. Individual decreases in Hb(mass) following detraining would need to be considered if using Hb(mass) for anti-doping purposes.

Blood passport has been suggested as an indirect tool to detect various kinds of blood manipulations. Autologous blood transfusions are currently undetectable, and the objective of this study was to examine the sensitivities of different blood markers and blood passport approaches in order to determine the best approach to detect autologous blood transfusions. Twenty‐nine subjects were transfused with either one ( n =8) or three ( n =21) bags of autologous blood. Hemoglobin concentration ([Hb]), percentage of reticulocytes (%ret) and hemoglobin mass (Hbmass) were measured 1 day before reinfusion and six times after reinfusion. The sensitivity and specificity of a novel marker, Hbmr (based on Hbmass and %ret), was evaluated together with [Hb], Hbmass and OFF‐hr by different passport methods. Our novel Hbmr marker showed superior sensitivity in detecting the highest dosage of transfused blood, with OFF‐hr showing equal or superior sensitivities at lower dosages. Hbmr and OFF‐hr showed superior but equal sensitivities from 1 to 4 weeks after transfusion compared with [Hb] and Hbmass, with Hbmass being the only tenable prospect to detect acute transfusions. Because autologous blood transfusions can be an acute practice with blood withdrawal and reinfusion within a few days, Hbmass seems to be the only option for revealing this practice.

The sensitivity of the athlete blood passport to detect blood doping may be improved by the inclusion of total hemoglobin mass (Hb mass ), but the comparability of Hb mass from different laboratories is unknown. To optimize detection sensitivity, the analytical variability associated with Hb mass measurement must be minimized. The aim of this study was to investigate the efficacy of using quality controls to minimize the variation in Hb mass between laboratories. Three simulated laboratories were set up in one location. Nine participants completed three carbon monoxide (CO) re‐breathing tests in each laboratory. One participant completed two CO re‐breathing tests in each laboratory. Simultaneously, quality controls containing Low (1–3%) and High (8–11%) concentrations of percent carboxyhemoglobin (%HbCO) were measured to compare hemoximeters in each laboratory. Linear mixed modeling was used to estimate the within‐subject variation in Hb mass , expressed as the coefficient of variation, and to estimate the effect of different laboratories. The analytic variation of Hb mass was 2.4% when tests were conducted in different laboratories, which reduced to 1.6% when the model accounted for between‐laboratory differences. Adjustment of Hb mass values using quality controls achieved a comparable analytic variation of 1.7%. The majority of between‐laboratory variation in Hb mass originated from the difference between hemoximeters, which could be eliminated using appropriate quality controls.

A high hemoglobin mass (Hb(mass)) is associated with a high maximum aerobic power (VO2max), however, the extent to which Hb(mass) is influenced by training is currently unclear. Accordingly, this study monitored changes in Hb(mass) and VO2max in 12 previously untrained adults (aged 18-25 years) following 40 days of regular physical activity. Hb(mass) and VO2max were assessed at the start and end of a 40-day physical activity program, which comprised of approximately 40 min of daily, moderate-intensity physical activity. Relative VO2max increased by 11.3%, yet there was no significant change in relative Hb(mass) (1.7%) and body mass (0.2%) during the 40-day period. There was a significant correlation between Hb(mass) and VO2max at the start of the study (r = 0.58, P = 0.05), but not between the change in relative VO2max and the change in relative Hb(mass) (r = -0.07, P = 0.83). Our results support the concept of relative stability in Hb(mass) with approximately 1 month of moderate-intensity physical activity suggesting that Hb(mass) may be used for talent identification and possibly for anti-doping purposes.

There is conflicting evidence whether hypoxia improves running economy (RE), maximal O(2) uptake (V(O)(2max)), haemoglobin mass (Hb(mass)) and performance, and what total accumulated dose is necessary for effective adaptation. The aim of this study was to determine the effect of an extended hypoxic exposure on these physiological and performance measures. Nine elite middle distance runners were randomly assigned to a live high-train low simulated altitude group (ALT) and spent 46+/-8 nights (mean+/-S.D.) at 2860+/-41m. A matched control group (CON, n=9) lived and trained near sea level ( approximately 600m). ALT decreased submaximal V(O)(2) (Lmin(-1)) (-3.2%, 90% confidence intervals, -1.0% to -5.2%, p=0.02), increased Hb(mass) (4.9%, 2.3-7.6%, p=0.01), decreased submaximal heart rate (-3.1%, -1.8% to -4.4%, p=0.00) and had a trivial increase in V(O)(2max) (1.5%, -1.6 to 4.8; p=0.41) compared with CON. There was a trivial correlation between change in Hb(mass) and change in V(O)(2max) (r=0.04, p=0.93). Hypoxic exposure of approximately 400h was sufficient to improve Hb(mass), a response not observed with shorter exposures. Although total O(2) carrying capacity was improved, the mechanism(s) to explain the lack of proportionate increase in V(O)(2max) were not identified.

The aim of this study was to determine the time course of changes in haemoglobin mass (Hb mass ) in well-trained cyclists in response to live high:train low (LHTL). Twelve well-trained male cyclists participated in a 3-week LHTL protocol comprising 3,000 m simulated altitude for ~14 h/day. Prior to LHTL duplicate baseline measurements were made of Hb mass , maximal oxygen consumption ( V O 2max ) and serum erythropoietin (sEPO). Hb mass was measured weekly during LHTL and twice in the week thereafter. There was a 3.3% increase in Hb mass and no change in V O 2max after LHTL. The mean Hb mass increased at a rate of ~1% per week and this was maintained in the week after cessation of LHTL. The sEPO concentration peaked after two nights of LHTL but there was only a trivial correlation ( r = 0.04, P = 0.89) between the increase in sEPO and the increase in Hb mass . Athletes seeking to gain erythropoietic benefits from moderate altitude need to spend >12 h/day in hypoxia.

The increase in oxygen transport elicited by several weeks of exposure to moderate to high altitude is used to increase physical performance when returning to sea level. However, many studies have shown that aerobic performance may not increase at sea level after a training block at high altitude. Subsequently, the concept of living high and training low was introduced in the early 1990s and was further modified to include simulated altitude using hypobaric or normobaric hypoxia. Review is given of the main studies that have used this procedure. Hematological changes are limited to insignificant or moderate increase in red cell mass, depending on the “dose” of hypoxia. Maximal aerobic performance is increased when the exposure to hypoxia is at least over 18 days. Submaximal performance and running economy have been found increased in several, but not all, studies. The tolerance (fatigue, sleep, immunological status, cardiac function) is good when the altitude or simulated altitude is not higher than 3000 m. Virtually no data are available about the effect of this procedure upon anaerobic performance. The wide spread of these techniques deserves further investigations.

Analysis of ∼100 years of home‐and‐away South American World Cup matches illustrate that football competition at moderate/high altitude (>2000 m) favors the home team, although this is more than compensated by the likelihood of sea‐level teams winning at home against the same opponents who have descended from altitude. Nevertheless, the home team advantage at altitudes above ∼2000 m may reflect that traditionally, teams from sea level or low altitude have not spent 1–2 weeks acclimatizing at altitude. Despite large differences between individuals, in the first few days at high altitude (e.g. La Paz, 3600 m) some players experience symptoms of acute mountain sickness (AMS) such as headache and disrupted sleep, and their maximum aerobic power (VO 2max ) is ∼25% reduced while their ventilation, heart rate and blood lactate during submaximal exercise are elevated. Simulated altitude for a few weeks before competition at altitude can be used to attain partial ventilatory acclimation and ameliorated symptoms of AMS. The variety of simulated altitude exposures usually created with enriched nitrogen mixtures of air include resting or exercising for a few hours per day or sleeping ∼8 h/night in hypoxia. Preparation for competition at moderate/high altitude by training at altitude is probably superior to simulated exposure; however, the optimal duration at moderate/high altitude is unclear. Preparing for 1–2 weeks at moderate/high altitude is a reasonable compromise between the benefits associated with overcoming AMS and partial restoration of VO 2max vs the likelihood of detraining.

Athletes regularly compete at 2,000–3,000 m altitude where peak oxygen consumption \((\dot{V}\hbox{\rm O}_{2{\rm peak}})\) declines ∼10–20%. Factors other than \(\dot{V}\hbox{\rm O}_{2{\rm peak}}\) including gross efficiency (GE), power output, and pacing are all important for cycling performance. It is therefore imperative to understand how all these factors and not just \(\dot{V}\hbox{\rm O}_{2{\rm peak}}\) are affected by acute hypobaric hypoxia to select athletes who can compete successfully at these altitudes. Ten well-trained, non-altitude-acclimatised male cyclists and triathletes completed cycling tests at four simulated altitudes (200, 1,200, 2,200, 3,200 m) in a randomised, counter-balanced order. The exercise protocol comprised 5 × 5-min submaximal efforts (50, 100, 150, 200 and 250 W) to determine submaximal \(\dot{V}\hbox{\rm O}_{2}\) and GE and, after 10-min rest, a 5-min maximal time-trial (5-minTT) to determine \(\dot{V}\hbox{\rm O}_{2{\rm peak}}\) and mean power output (5-minTTpower). \(\dot{V}\hbox{\rm O}_{2{\rm peak}}\) declined 8.2 ± 2.0, 13.9 ± 2.9 and 22.5 ± 3.8% at 1,200, 2,200 and 3,200 m compared with 200 m, respectively, P < 0.05. The corresponding decreases in 5-minTTpower were 5.8 ± 2.9, 10.3 ± 4.3 and 19.8 ± 3.5% (P < 0.05). GE during the 5-minTT was not different across the four altitudes. There was no change in submaximal \(\dot{V}\hbox{\rm O}_{2}\) at any of the simulated altitudes, however, submaximal efficiency decreased at 3,200 m compared with both 200 and 1,200 m. Despite substantially reduced power at simulated altitude, there was no difference in pacing at the four altitudes for athletes whose first trial was at 200 or 1,200 m; whereas athletes whose first trial was at 2,200 or 3,200 m tended to mis-pace that effort. In conclusion, during the 5-minTT there was a dose–response effect of hypoxia on both \(\dot{V}\hbox{\rm O}_{2{\rm peak}}\) and 5-minTTpower but no effect on GE.

PURPOSEA new method to estimate hemoglobin mass (Hbmass) requires capillary blood and rebreathing a carbon-monoxide (CO) bolus for 2 min. We hypothesized that incomplete circulatory mixing of CO could confound this method, so we compared capillary with venous blood to determine whether sampling site altered the percentage of carboxyhemoglobin (%HbCO) and the reliability and accuracy of the "2-min Hbmass." The conventional 20-min CO-rebreathing procedure was used as the Hbmass criterion.METHODSIn the first experiment (N=12), both fingertip capillary and antecubital venous blood were sampled 4 and 6 min after commencing 2 min of CO-rebreathing. Within 8 d, these subjects completed two 2-min and one 20-min CO-rebreathing periods. For the latter, capillary and venous blood were collected simultaneously after two 10-min periods of rebreathing. In a second experiment (N=6), both capillary and venous blood were sampled 4, 6, 8, 10, and 12 min after commencing 2 min of CO-rebreathing. A third experiment (N=6) evaluated the reliability of a modified 2-min CO-rebreathing test with capillary blood sampled at minutes 8 and 10.RESULTSTypical error (TE) for the first two 2-min tests was 1.1% (90% confidence limits 0.9-1.8%), but the average Hbmass from 2-min capillary blood was 4.8% lower than from venous blood for the 20-min procedure. In the second experiment, peak venous %HbCO occurred at minute 6, and the difference between capillary and venous values was minimal (mean+/-SD; 0.08+/-0.07, 0.01+/-0.09) at minutes 8 and 10. TE for the third experiment was 1.2% (0.8-2.5%).CONCLUSIONA modified 2-min CO-rebreathing procedure using capillary or venous blood sampled 8 and 10 min after starting CO-rebreathing allows complete circulatory mixing and provides an accurate and reliable estimate of Hbmass.

Hypoxia and exercise each modulate muscle Na+, K+ATPase activity. We investigated the effects on muscle Na+, K+ATPase activity of only 5 nights of live high, train low hypoxia (LHTL), 20 nights consecutive (LHTLc) versus intermittent LHTL (LHTLi), and acute sprint exercise. Thirty-three athletes were assigned to control (CON, n = 11), 20-nights LHTLc (n = 12) or 20-nights LHTLi (4 × 5-nights LHTL interspersed with 2-nights CON, n = 10) groups. LHTLc and LHTLi slept at a simulated altitude of 2,650 m (FIO2 0.1627) and lived and trained by day under normoxic conditions; CON lived, trained, and slept in normoxia. A quadriceps muscle biopsy was taken at rest and immediately after standardised sprint exercise, before (Pre) and after 5-nights (d5) and 20-nights (Post) LHTL interventions and analysed for Na+, K+ATPase maximal activity (3-O-MFPase) and content ([3H]-ouabain binding). After only 5-nights LHTLc, muscle 3-O-MFPase activity declined by 2% (P < 0.05). In LHTLc, 3-O-MFPase activity remained below Pre after 20 nights. In contrast, in LHTLi, this small initial decrease was reversed after 20 nights, with restoration of 3-O-MFPase activity to Pre-intervention levels. Plasma [K+] was unaltered by any LHTL. After acute sprint exercise 3-O-MFPase activity was reduced (12.9 ± 4.0%, P < 0.05), but [3H]-ouabain binding was unchanged. In conclusion, maximal Na+, K+ATPase activity declined after only 5-nights LHTL, but the inclusion of additional interspersed normoxic nights reversed this effect, despite athletes receiving the same amount of hypoxic exposure. There were no effects of consecutive or intermittent nightly LHTL on the acute decrease in Na+, K+ATPase activity with sprint exercise effects or on plasma [K+] during exercise.

PURPOSE a) Compare the predictive potential of speed and CSA(hip) (Computer Science Applications accelerometer positioned on the hip) for level terrain walking METs (1 MET = VO2 of 3.5 mL.kg(-1).min(-1)) and energy expenditure (kcal.min(-1)); b) cross-validate previously published CSA(hip)- and speed-based MET and energy expenditure prediction equations; c) measure self-paced walking speed, exercise intensity (METs) and energy expenditure in the middle aged population. METHODS Seventy-two 35- to 45-yr-old volunteers walked around a level, paved quadrangle at what they perceived to be a moderate pace. Oxygen consumption was measured using the criterion Douglas bag technique. Speed, CSA(hip), heart rate, and Borg rating of perceived exertion were also monitored. RESULTS Speed explained 10% more variance of walking METs than CSA(hip). Speed and mass explained 8% more variance of walking energy expenditure (kcal.min) than CSA(hip) and mass. The best previously published regression equations predict our walking METs and energy expenditures within 95% prediction limits of +/- 0.7 METs and +/- 1.0 kcal.min(-1), respectively. Women paced themselves at a significantly higher mean speed (5.5 km.h(-1)) and intensity (4.1 METs) than their male counterparts (5.2 km.h(-1) and 3.8 METs). Both genders expended approximately 0.75 kcal.kg(-1) for every kilometer of level terrain walked. CONCLUSION Speed-based MET and energy expenditure predictions during level terrain walking were more accurate than those utilizing CSA(hip).

Objectives: To assess the influence of moderate, acute weight loss on on-water rowing performance when aggressive nutritional recovery strategies were used in the two hours between weigh in and racing. Methods: Competitive rowers (n  =  17) undertook three on-water 1800 m time trials under cool conditions (mean (SD) temperature 8.4 (2.0)°C), each separated by 48 hours. No weight limit was imposed for the first time trial—that is, unrestricted body mass (UNR1). However, one of the remaining two trials followed a 4% loss in body mass in the previous 24 hours (WT−4%). No weight limit was imposed for the other trial (UNR2). Aggressive nutritional recovery strategies (WT−4%, 2.3 g/kg carbohydrate, 34 mg/kg Na+, and 28.4 ml/kg fluid; UNR, ad libitum) were used in the first 90 minutes of the two hours between weigh in and performance trials. Results: WT−4% had only a small and statistically non-significant effect on the on-water time trial performance (mean 1.0 second, 95% confidence interval (CI) −0.9 to 2.8; p  =  0.29) compared with UNR. This was despite a significant decrease in plasma volume at the time of weigh in for WT−4% compared with UNR (−9.2%, 95% CI −12.8% to −5.6%; p<0.001). Conclusions: Acute weight loss of up to 4% over 24 hours, when combined with aggressive nutritional recovery strategies, can be undertaken with minimal impact on on-water rowing performance, at least in cool conditions.

The volume of red blood cells (V(RBC)) is used routinely in the diagnostic workup of polycythemia, in assessing the efficacy of erythropoietin administration, and to study factors affecting oxygen transport. However, errors of various methods of measurement of V(RBC) and related parameters are not well characterized. We meta-analyzed 346 estimates of error of measurement of V(RBC) for techniques based on Evans blue (V(RBC,Evans)), 51chromium-labeled red blood cells (V(RBC,51Cr)), and carbon monoxide (CO) rebreathing (V(RBC,CO)), as well as hemoglobin mass with the carbon-monoxide method (M(Hb,CO)), in athletes and active and inactive subjects undergoing various experimental and control treatments lasting minutes to months. Subject characteristics and experimental treatments had little effect on error of measurement, but measures with the smallest error showed some increase in error with increasing time between trials. Adjusted to 1 day between trials and expressed as coefficients of variation, mean errors for M(Hb,CO) (2.2%; 90% confidence interval 1.4-3.5%) and V(RBC,51Cr) (2.8%; 2.4-3.2%) were much less than those for V(RBC,Evans) (6.7%; 4.9-9.4%) and V(RBC,CO) (6.7%; 3.4-14%). Most of the error of V(RBC,Evans) was due to error in measurement of volume of plasma via Evans blue dye (6.0%; 4.5-7.8%), which is the basis of V(RBC,Evans). Most of the error in V(RBC,CO) was due to estimates from laboratories with a relatively large error in M(Hb,CO), the basis of V(RBC,CO). V(RBC,51Cr) and M(Hb,CO) are the best measures for research on blood-related changes in oxygen transport. With care, V(RBC,Evans) is suitable for clinical applications of blood-volume measurement.