Altitude training for the marathon

JA, Duque L, Chaves-Gomez S, Cristancho-Mejía E, Schmidt WFJ. Hemoglobin Mass, Blood Volume and VO2max of Trained and Untrained Children and Adolescents Living at Different Altitudes

Introduction: To a considerable extent, the magnitude of blood volume (BV) and hemoglobin mass (Hbmass) contribute to the maximum O2-uptake (VO2max), especially in endurance-trained athletes. However, the development of Hbmass and BV and their relationships with VO2max during childhood are unknown. The aim of the present cross-sectional study was to investigate Hbmass and BV and their relationships with VO2max in children and adolescents. In addition, the possible influence of endurance training and chronic hypoxia was evaluated.

Methods: A total of 475 differently trained children and adolescents (girls n = 217, boys n = 258; untrained n = 171, endurance trained n = 304) living at two different altitudes (∼1,000 m, n = 204, ∼2,600 m, n = 271) and 9–18 years old participated in the study. The stage of puberty was determined according to Tanner; Hbmass and BV were determined by CO rebreathing; and VO2max was determined by cycle ergometry and for runners on the treadmill.

Results: Before puberty, there was no association between training status and Hbmass or BV. During and after puberty, we found 7–10% higher values in the trained groups. Living at a moderate altitude had a uniformly positive effect of ∼7% on Hbmass in all groups and no effect on BV. The VO2max before, during and after puberty was strongly associated with training (pre/early puberty: boys +27%, girls +26%; mid puberty: +42% and +45%; late puberty: +43% and +47%) but not with altitude. The associated effects of training in the pre/early pubertal groups were independent of Hbmass and BV, while in the mid- and late pubertal groups, 25% of the training effect could be attributed to the elevated Hbmass.

Conclusions: The associated effects of training on Hbmass and BV, resulting in increased VO2max, can only be observed after the onset of puberty.

A Clinician Guide to Altitude Training for Optimal Endurance Exercise Performance at Sea Level

Constantini, Keren, Daniel P. Wilhite, and Robert F. Chapman. A clinician guide to altitude training for optimal endurance exercise performance at sea level. High Alt Med Biol. 18:93-101, 2017.-For well over 50 years, endurance athletes have been utilizing altitude training in an effort to enhance performance in sea level competition. This brief review will offer the clinician a series of evidence-based best-practice guidelines on prealtitude and altitude training considerations, which can ultimately maximize performance improvement outcomes.

Endurance Training on Congenital Valvular Regurgitation: An Athlete Case Series

BACKGROUND

Both intense endurance training and valvular regurgitation place a volume load on the right and left ventricles, potentially leading to dilation, but their effects in combination are not well-known.

PURPOSE

The purpose of this case series is to describe the combined volume load of intense endurance athletic training and regurgitant valvular disease as well as the challenging assessment of each component's cardiovascular effect.

METHODS

In this article, the clinical course of three elite endurance athletes with congenital valvular disease were reviewed.

RESULTS

A swimmer with aortic regurgitation, a cyclist with aortic regurgitation, and a cyclist with pulmonary regurgitation were found to have severe dilation of the associated ventricles despite continuing to train at an elite level without symptoms.

CONCLUSIONS

Because of the cumulative effects of endurance training and valvular regurgitation, each athlete manifested ventricular dilation out of proportion to their valvular disease and symptoms. Although the effects of congenital valvular disease and athletic remodeling on ventricular dilation have been thoroughly studied individually, their cumulative effect is not well understood. This complicates the assessment of athletes with valvular regurgitation and underscores the need for athlete-specific recommendations for valve replacement.

Timing of return from altitude training for optimal sea level performance

While a number of published studies exist to guide endurance athletes with the best practices regarding implementation of altitude training, a key unanswered question concerns the proper timing of return to sea level prior to major competitions. Evidence reviewed here suggests that, altogether, the deacclimatization responses of hematological, ventilatory, and biomechanical factors with return to sea level likely interact to determine the best timing for competitive performance.

Effects of individual aerobic performance on finish time in mountain running

It was hypothesized that for each mountain running competition, there is a certain individual performance level below which running times increase dramatically. The running times of 869 finishers of 3 international mountain running competitions have been analysed. A hyperbolic association was demonstrated between finish times in mountain running competitions and individual performance at the anaerobic threshold (VO2AT(Race)). Due to the non-linear association, there is an increasing effect on both the finish time and the change of finish time with decreasing aerobic performance. In all three competitions, the change of finish time is about 7 times more pronounced in mountain runners with the lowest VO2ATL,, compared to those with the highest values of VO2AT(Race). Both athletes and organizers should keep in mind these effects of decreasing aerobic performance on running times and potentially associated risks.

Aspectos relacionados com a otimização do treinamento aeróbio para o alto rendimento

O objetivo deste trabalho foi apresentar recomendações visando à otimização do treinamento aeróbio, a partir do conhecimento dos índices de aptidão funcional e seus mecanismos fisiológicos. Em atletas altamente treinados, a precisão na elaboração do treinamento pode ser o meio mais seguro para a melhora do rendimento, pois nesses indivíduos é comum a carga de treinamento oscilar entre o estimulo insuficiente e o aparecimento do excesso de treinamento. Existe, portanto, uma variedade muito grande de fatores que devem ser considerados na elaboração de um programa de treinamento. O entendimento dos mecanismos de fadiga e das respostas fisiológicas associadas às diferentes durações e intensidades de exercício é essencial para uma correta elaboração das sessões de treinamento. Além disso, treinos intervalados de alta intensidade são imprescindíveis para melhora de rendimento em atletas altamente treinados, porém, é recomendado que ele seja realizado após um razoável período de recuperação das sessões de treino anteriores. Assim, o contato entre o atleta e o treinador é importante para um planejamento cuidadoso dos períodos de recuperação antes da ocorrência de fadiga excessiva. O treinador deveria arquivar um histórico das cargas de treino e recuperações, aprendendo com a própria experiência os tipos de cargas que podem ser toleradas individualmente. Entre os fatores que podem afetar o rendimento aeróbio, o planejamento de um aquecimento apropriado e as condições ambientais adversas são aspectos muito importantes. Após reunir todas essas informações, é possível elaborar as bases do treinamento (frequência, volume, intensidade e recuperação) visando melhora contínua do rendimento aeróbio.

Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

Oxidative stress occurs at altitude, and physical exertion might enhance this stress. In the present study, we investigated the combined effects of exercise and moderate altitude on redox balance in ten endurance exercising biathletes, and five sedentary volunteers during a 6-week-stay at 2,800 m. As a marker for oxidative stress, hydrogen peroxide (H(2)O(2)) was analyzed by the biosensor measuring system Ecocheck, and 8-iso prostaglandin F2alpha (8-iso PGF2alpha) was determined by enzyme immunoassay in exhaled breath condensate (EBC). To determine the whole blood antioxidative capacity, we measured reduced glutathione (GSH) enzymatically using Ellman's reagent. Exercising athletes and sedentary volunteers showed increased levels of oxidative markers at moderate altitude, contrary to our expectations; there was no difference between both groups. Therefore, all subjects' data were pooled to examine the oxidative stress response exclusively due to altitude exposure. H(2)O(2) levels increased at altitude and remained elevated for 3 days after returning to sea level (p < or = 0.05). On the other hand, 8-iso PGF2alpha levels showed a tendency to increase at altitude, but declined immediately after returning to sea level (p < or = 0.001). Hypoxic exposure during the first day at altitude resulted in elevated GSH levels (p < or = 0.05), that decreased during prolonged sojourn at altitude (p < or = 0.001). In conclusion, a stay at moderate altitude for up to 6 weeks increases markers of oxidative stress in EBC independent of additional endurance training. Notably, this oxidative stress is still detectable 3 days upon return to sea level.

Training to maximize economy of motion in running gait

Recent reviews of how training affects running performance have indicated, to varying degrees, that running economy (RE) is a determinant of running performance. However, the literature suggests that the relationship between training-induced changes in biomechanics and RE is still largely unknown. While there is some evidence that high intensity interval training, plyometrics, and altitude/hypoxia training can improve economy, it remains unclear how these improvements are mediated. In addition, although it is clear from the literature that meaningful differences in RE exist among runners, the causes for the inherent differences are not clear. Consequently, suggestions are made to explore more individualized and integrated models of the determinants of performance that might better explain the interrelatedness of gait, RE, V.O2max, and peak performance.