Physiological and biological longitudinal follow-up of elite and amateur athletes: a study of confounding factors for the ABP

Code: 19D06RF

The goal of our first study is to investigate the correlation between the Athlete Biological Passport (ABP) variables and performance data from competitive elite athletes analyzed from training and racing power outputs (elite cyclists), apneic times, depth or distance (trained apneic divers) and endurance capacity (sport students). In this way, our study would challenge the complexity of confounding factors affecting the interpretation of the ABP. Testing the hypothesis that variations in performances are related to variations in the ABP in different sport disciplines would allow the ABP model to be strengthened. Finally, our project will evaluate the range of variability of identified confounding factors altering the blood formula in a population of trained apnea divers. It is hypothesized that breath-holding methods and specific apnea training techniques may significanlty alter blood parameters from the ABP. Indeed, it has already been shown that 3 repeated breath-holdings increase hemoglobin concentration ([Hb]) in divers, skiers and untrained humans acutely while an extension of such findings in the context of the ABP is still needed. Overall, out study aims at improving the ABP by challenging the individual whithin-subject variance in light of known confounding factors. The objectives of this study are threefold: firstly, this study will allow to further investigate the relationship between Hbmass and aerobic performances in three distinct populations (elite cyclists, apnea divers, sport students). Second, blood variables data collected monthly will allow us to discriminate between the influence of specific confounding factors thanks to the multi-sourcing data and heterogeneous groups (cyclists, apnea divers, sport students). Overall, this study will enable us to strengthen the ABP after looking at the within-subject variations to propose a robust evaluation of known underlying confoundng factors.

Second, we will conduct a study investigating the influence of the menstrual cycle on hematological varaibles to identify potential variations factors specific to blood losses and hormonal variations.

Thirdly, we will conduct a study on elite race walkers to describe hematological variations observed before, during and after a prolonged exposure to i) altitude and ii) heat in their final preparation block before a major competition.

Main Findings

In the supported project, we first conducted a study to investigate the relationship between Hbmass and aerobic performances in three distinct populations (elite cyclists, apnea divers, sport students) with blood variables data collected monthly to discriminate between the influence of specific confounding factors thanks to the multi-sourcing data and heterogeneous groups (cyclists, apnea divers, sport students). This resulted in a peer-reviewed publication (1). Although individual hematological variations were observed, all ABP variables remained within the individually calculated limits. We showed that acute training load variations in elite cyclists significantly affect (Hb), likely due to short-term PV fluctuations, underlining the importance of considering training load when interpreting individual ABP variations for antidoping purposes.

Second, we conducted a study investigating the influence of the menstrual cycle on hematological variables (total Hbmass, ABP variables & indicators of plasma volume changes) to identify potential variations factors specific to blood losses and hormonal variations. This resulted in another peer-reviewed publication (2). A multi-parametric model previously validated in elite cyclists was applied to compare inferred and actual PV variations. Some significant intra-individual PV variations were observed, in good agreement with the estimated PV changes; and it can be concluded that estimating PV variations may help interpret individual ABP haematological profiles in women.

Thirdly, we had planned to conduct a study on elite race walkers to describe hematological variations observed before, during and after a prolonged exposure to i) altitude and ii) heat in their final preparation block before a major competition. However, this could not be completed yet, due to 2020/2021 travel restrictions with the context of the pandemic. We worked however instead on the monitoring data from the apnea divers cohort. This resulted in a peer reviewed publication (3). Whilst we hypothesized that regular breath-hold training could affect or alter ABP variables, the results of our study do not outline any particular significant effect of regular breath-hold training on ABP variables. Overall, this project will enable us to strengthen the ABP after looking at the within-subject variations to propose a robust evaluation of known underlying confounding factors.

PUBLICATIONS

(1) Astolfi T, Crettaz von Roten F, Kayser B, Saugy M, Faiss R. The Influence of Training Load on Hematological Athlete Biological Passport Variables in Elite Cyclists. Front Sports Act Living. 2021 Mar 18;3:618285. doi:10.3389/fspor.2021.618285. PMID: 33817634

(2) Basile Moreillon, Tristan Equey, Tiffany Astolfi, Olivier Salamin 1 3, Raphael Faiss. Removal of the influence of plasma volume fluctuations for the athlete biological passport and stability of haematological variables in active women taking oral contraception. Drug Test Anal 2022 Jun;14(6):1004-1016.doi: 10.1002/dta.3218.

(3) Astolfi, T., Crettaz Von Roten, F., Kayser, B., Saugy, M., & Faiss, R. Hematological variables in recreational breath-hold divers: a longitudinal study. J Sports Med Phys Fitness. 2021 Sep 9. doi: 10.23736/S00224707.21.12918-4.