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Blood Doping

Blood Doping. Maximal Aerobic Power. Endurance sports which involve using large muscle groups, often during long periods of time. Other factors: Aerobic exercise efficiency Aerobic-anaerobic balance Anaerobic capacity Substrate availability Muscle strength Psychological factors.

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Blood Doping

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  1. Blood Doping

  2. Maximal Aerobic Power • Endurance sports which involve using large muscle groups, often during long periods of time. • Other factors: • Aerobic exercise efficiency • Aerobic-anaerobic balance • Anaerobic capacity • Substrate availability • Muscle strength • Psychological factors

  3. Maximal Oxygen Uptake (VO2max) • Some elites have achieved >90 mL/kg/min! • Due to large maximal cardiac output (Qmax, upwards of 40 L/min!), and • Large arteriovenous oxygen difference (a-vO2diff). • However, peak heart rate (HRmax) nothing special. • Therefore, the huge Qmax is due to large stroke volume (>200 mL have been recorded for elite athletes) • Performance has improved over last 50 years, the highest values of VO2max have not.

  4. What Limits VO2max? • First addressed by Hill and Lupton (1923) VO2max VO2 Time

  5. What Limits VO2max? • Pulmonary hemoglobin (Hb) saturation? • Peripheral oxygen transport? • Capillary density? • Mitochondrial mass? • Enzyme concentrations? • Muscle size? • Delivery of oxygen?

  6. [Hb] • Acute blood loss, carbon monoxide, and anemia: • Increase HR, blood lactate, rating of percieved exertion. • No relationship in population between [Hb] & VO2max • Total Hb • Training does not increase [Hb] • Marked increase in total Hb • In fact, training is associated with dilutionalpseudoanemia, a.k.a., “sports anemia”

  7. Increasing [Hb]: Blood Doping • 2-4 units (450-1800 mL) of whole blood drawn • RBCs separated from plasma (centrifugation), frozen, and stored in glycerol. • 2-3 months needed to restore [Hb] in hard training athletes. • 3-5 days before competition, RBCs are washed with saline and infused • Modern techniques preserve RBC function

  8. Blood Doping

  9. Effects of Blood Doping • First BD experiment: 1947 • Performance was enhanced • Essentially no differences in performance with infusion of whole blood versus packed RBCs • O2-carrying capacity is what counts! • Blood volume not changed, or only slightly increased within 12-14 d after infusion.

  10. Effects of Blood Doping • Hb and hematocrit (Hct) increase • Individual variation, of unknown origin • After reinfusion of RBCs, submaximal VO2 not increased. However: • Q reduced • HR lower • SV basically unchanged • Blood lactate concentration reduced • Enhanced VO2max and prolonged time to exhaustion. • Increased oxygen availability • ↑[Hb] (average increase of 9 g/L) • ↑Qmax • ↑VO2max (average increase of 0.31 L/min) • Qmax ∙ CaO2 increased after infusion • Increased amount of O2 “offered” to peripheral tissues during maximal exercise. • Increase is linear up to [Hb] of at least 200 g/L – no difference in increase from anemia to normal; or normal to higher value. • Bottom line: [Hb] important for performance!

  11. Effects of Blood Volume (BV) Expansion • Without blood doping, blood volume and total Hb are positively related to VO2max. • In fact, expanded BV is one of the first adaptations to exercise training! • What about plasma volume (PV) expansion? • Macrodex = PV expander • ↑SV (Diastolic filling, Frank-Starling mechanism) • Thus, ↑Qmax (HR unchanged) • However, the PV expansion results in dilution of Hb (↓[Hb]) in trained individuals • Acute PV expansion has only been shown to increase VO2 max untrained individual (↑PV may offset ↓[Hb]). • Bottom line: no change in VO2max with PV expansion alone, unless you are untrained!

  12. Risks & Side Effects Associated with Blood Doping? • Blood pressure (BP)? • No effect of blood doping on systolic BP during submaximal exercise. • Presumably no effect on blood viscosity. • No increase in arterial BP at rest or exercise after reinfusion of RBCs • Heterologous versus autologous infusion of packed RBCs or whole blood • Allergic reactions and infection possible with heterologous blood infusion.

  13. Who’s [suspected of] been Blood Doping? • US Olympic cycling team, 1984. • Tyler Hamilton? Failed one test for heterologous RBCs • Lawyers argued he’s a chimera, then proposed a “vanishing twin” hypothesis. • Operacion Puerto (2006) • hundreds of Spanish cyclists implicated. • Russian hockey star Alexei Cherepanov (died, 2008) • German speed skater & 5-time olympic gold medalist Claudia Pechstein banned for two years in 2009.

  14. Detecting Blood Doping • Heterologous blood infusion can be detected with advanced hematological and DNA techniques. • Detecting ↑[Hb], ↑RBC fragility, ↑bilirubin, ↑iron, ↓erythropoietin • Need multiple blood samples from individual before and after infusion – logistically impractical • After 2007 Tour de France doping scandals, cyclists required to carry “blood passport”. • WADA promises that a reliable method for detection of autologous blood doping will be in place soon • Method and date of release are kept secret to avoid “tipping off athletes” • May assess the levels of 2,3-bisphosphglycerate in RBCs, which is degraded over time in stored RBCs. • Bottom line: currently, no practical method is available for detection of autologous infusion of whole blood or packed RBCs.

  15. All’s Fair in Love and War: Military Blood Doping • US Special Forces – Fort Bragg, beginning 1993. • 24 before mission, small amount of packed RBCs infused into soldiers. • Australian Defense Special Forces, 1998 • Senior nutritionist: “all’s fair in love and war…What we are trying to gain is an advantage over any potential adversary…What we will have is a head start.” • Pugliese, David (2002). Canada's Secret Commandos. • Of the supplements/techniques tested for military performance enhancement, over 50 were rejected. • Just 6 were approved: caffeine, ephedrine, some energy drinks (mostly caffeine), modafinil, creatine and blood doping!

  16. Conclusions • Blood doping improves VO2max and endurance performance • Due to increased [Hb], and thus oxygen transport • Carries relatively little risk if conducted properly (in a clinical setting) with autologous blood. • Too many RBCs reinfused will thicken blood, increasing risk of stoke, heart attack and pulmonary embolism. • Currently, no practical method for detecting the savvy blood doper (see: hematocrit regulations in in next chapter). • The future? • Hb solutions • Artificial oxygen-carriers

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