Hemoglobin Mass, Blood Volume and VO2max of Trained and Untrained Children and Adolescents Living at Different Altitudes

Abstract

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.

Effect of hypobaric hypoxia on hematological parameters related to oxygen transport, blood volume and oxygen consumption in adolescent endurance-training athletes

“…Similarly, our latest research involving a large sample of children and adolescents from both sexes concluded that the associated effects of endurance training on Hbt and BV is only observed after the onset of puberty. 13 Our results, shown in Fig. 2 , Fig.…”

“…Regarding studies focused on the adolescent population, comparable results have been reported for elite swimmers 46 and skiers, 47 , 48 although a wide inter-individual variability was clear in the erythropoietic response in elite adolescent swimmers. 49 To our knowledge, only a few studies have dealt with MA elite athlete permanent residents and, apart from our recent report 13 none involved the adolescent population. Schmidt et al.…”

“…Most studies on the relationship between Hbt and VO 2 peak have been conducted on trained adults and only a few on adolescents. 8 , 9 , 10 , 11 , 12 Since there is no conclusive evidence on how simultaneous factors such as exposition to hypoxia and aerobic endurance training affect children and adolescents, we engaged in research whose main goals were to study the behavior of blood oxygen transport-related parameters and VO 2 peak throughout childhood and puberty in boys and girls 13 and the hormonal regulation of erythropoiesis. 14 As part of this research, the aim of our work here was to investigate the effects of moderate altitude residence on oxygen transport-related hematological parameters and on VO 2 peak in adolescent endurance athletes participating in different sport disciplines.…”

Increased Sports Performance Determined by the Altitude Factor among Senior Mountain Runners

“…It has been observed in several studies that low atmospheric pressure causes hypoxia (Girard, 2022;Billaut et al, 2022) and reaching a lower max VO 2 (Pühringer et al, 2022), but performing a cantonment of preparation at altitude with a duration of at least 4-6 weeks (Mujika et al, 2019;Deldicque, 2022). leads to the increase of biochemical parameters such as: 2.3-BPG, Hb, RBC, EPO (Płoszczyca et al, 2018;Baranauskas et al, 2022;Beidleman et al, 2017) and implicitly of the performance sports (Girard et al, 2020) and VO 2 max (Lukanova-Jakubowska et al, 2022;Mancera-Soto et al, 2022 )) Also, it has been observed that if the tendency of SpO 2 is to decrease in altitude conditions, the rate of lactate recovery is not influenced, which is why an individual response to hypoxia is obtained from each athlete.…”

Neuromuscular Adaptations in Endurance‐Trained Male Adolescents Versus Untrained Peers: A 9‐Month Longitudinal Study

“…A delimitation of the study is that only male adolescents were studied. Even if cardiorespiratory adaptations to endurance training were found to be comparable between girls and boys around APHV [47, 48], further studies should be done, including in adolescent girls, to investigate the influence of sex on neuromuscular adaptations in addition to the effects of growth and maturation, and endurance training. Another delimitation is that the study was not designed as a randomized, controlled exercise training intervention.…”