Presentation is loading. Please wait.

Presentation is loading. Please wait.

Blood Doping. Maximal Aerobic Power Endurance sports which involve using large muscle groups, often during long periods of time. Other factors: – Aerobic.

Similar presentations

Presentation on theme: "Blood Doping. Maximal Aerobic Power Endurance sports which involve using large muscle groups, often during long periods of time. Other factors: – Aerobic."— Presentation transcript:

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 (VO 2max ) 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-vO 2 diff). 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 VO 2max have not.

4 What Limits VO 2max ? First addressed by Hill and Lupton (1923) Time VO 2max VO2VO2

5 What Limits VO 2max ? 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] & VO 2max – Total Hb Training does not increase [Hb] – Marked increase in total Hb – In fact, training is associated with dilutional pseudoanemia, 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 – O 2 -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 VO 2 not increased. However: – Q reduced – HR lower – SV basically unchanged – Blood lactate concentration reduced Enhanced VO 2max and prolonged time to exhaustion. Increased oxygen availability – ↑[Hb] (average increase of 9 g/L) – ↑Qmax – ↑VO 2max (average increase of 0.31 L/min) – Qmax ∙ C a O 2 increased after infusion – Increased amount of O 2 “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 VO 2max. – 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 VO 2max 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 VO 2max 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

Download ppt "Blood Doping. Maximal Aerobic Power Endurance sports which involve using large muscle groups, often during long periods of time. Other factors: – Aerobic."

Similar presentations

Ads by Google