A novel mixed living high training low intervention and the hematological module of the athlete biological passport

Abstract

Exposure to either natural or simulated hypoxia induces hematological adaptations that may affect the parameters of the Athlete Biological Passport (ABP). The aim of the present study was to examine the effect of a novel, mixed hypoxic dose protocol on the likelihood of producing an atypical ABP finding. Ten well‐trained middle‐distance runners participated in a “live high, train low and high” (LHTLH) altitude training camp for 14 days. The participants spent ˜6 hr.d‐1 at 3000–5400 m during waking hours and ˜10 h.d‐1 overnight at 2400–3000 m simulated altitude. Venous blood samples were collected before (B0), and after 1 (D1), 4 (D4), 7 (D7), and 14 (D14) days of hypoxic exposure, and again 14 days post exposure (P14). Samples were analyzed for key parameters of the ABP including reticulocyte percentage (Ret%), hemoglobin concentration ([Hb]), and the OFF‐score. The ABP adaptive model was administered at a specificity of 99% to test for atypical findings. We found significant changes in [Hb] and Ret% during the hypoxic intervention. Consequently, this led to ABP threshold deviations at 99% specificity in three participants. Only one of these was flagged as an “atypical passport finding” (ATPF) due to deviation of the OFF‐score. When this sample was evaluated by ABP experts it was considered “normal”. In conclusion, it is highly unlikely that the present hypoxic exposure protocol would have led to a citation for a doping violation according to WADA guidelines.

Fluctuations in hematological athlete biological passport biomarkers in relation to the menstrual cycle

“…7 In addition to blood doping, several factors may affect the hematological profile, for example, altitude exposure, physical exercise, time of the day and year, and hydration status. [8][9][10][11][12] An increased knowledge of how these and other confounders interact with the hematological passport will further improve the interpretation of ABP results.…”

Factors confounding the athlete biological passport: a systematic narrative review

“…Moreover, an increase in Ret% was reported during hypoxic exposure [82,83], while Ret% decreased upon return to a lower altitude [35]. Similar blood variations were reported following living high-training low (LHTL) protocols with, however, a more pronounced increase in [Hb] [84–87]. Variations due to hypoxic training observed immediately after altitude exposure were reported to persist three weeks after returning to sea level [35,84].…”

“…Nevertheless, haematological variations following hypoxic training are contradictory [82,105] and not systematically reported [85,109], possibly due to initial fitness, initial fatigue or iron status [66,110]. It seems unlikely, then, that training in a hypoxic environment could lead to a misinterpretation of an athlete's blood profiles [87] if duly reported in the doping control forms as requested by WADA.…”

“…heat acclimation or hypoxic training) on haematological biomarkers remain debatable due to significant differences in individual responses [104,105]. Studies investigating specific ABP confounders generally report variations within individual limits of the adaptive model [13,85,87,98]. The scientific level of ABP experts reviewing passports and their efforts to do so with the latter factors in mind can further limit misinterpretations of ABP profiles caused by the confounding factors identified in this review.…”

Annual banned‐substance review: Analytical approaches in human sports drug testing 2019/2020

“…Further, Voss et al reported on the effect of a 14‐day living/training intervention with controlled hypoxia conditions (hypoxic dose equivalent approximately 792 km * h) on the ABP. The expected and observed significant changes in ret% and [Hb] triggered an ATPF in one out of the 10 well‐trained middle‐distance runners participating in the study; however, the consideration of the overall ABP profile and complementary information of high altitude exposure excluded attributing the ATPF to a “doping scenario.” 187 …”