One way to increase the aerobic capacity-resistance of an athlete (VO2, max), is to enhance erythropoiesis.
Studies have shown that one gram of hemoglobin (Hb) can bind ~ 1.34 ml of 02.
Thus, an increased amount of Hb also increases the amount of O2 that can be delivered to the tissues.
Moreover, the O2 transport capacity and maximal O2 uptake (VO2, max) in athletes directly correlate with aerobic performance.
Therefore, the increase of hematocrit, hemoglobin and consequently myoglobin is a clear advantage for aerobic athletic performance.=
Myoglobin is a protein that binds oxygen and incorporates it into the skeletal-striated muscles.
Moreover, this hemoprotein is capable of releasing O2 during periods of hypoxia or anoxia.
The hematocrit can increases in the following ways:
1) by living at altitude of over 2000 meters for at least one month (four weeks).
As known, in higher altitude the air is thinner and therefore the oxygen content is lower.
This is a direct stimulus to the kidneys to produce the growth factor erythropoietin (EPO), which stimulates bone marrow and enhances erythropoiesis.
Then the athlete with increased hemoglobin can train at sea level, where O2 concentration is maximum.
2) by having a diet rich in beef-buffalo meat and supplementation by liver amino’s, combined with intramuscular injections of cyanocobalamin, and folic acid tablets.
These ingredients (iron, vitamin B12, folate) are the main substrates that ensure hemoglobin’s synthesis and enhance erythrocytosis.
3) by the use of androgens (testosterone and synthetic derivatives-AAS), that stimulate erythropoietin (EPO) release, increase red bone marrow activity, iron incorporation into the red cells and consequently elevate hemoglobin-hematocrit.
4) by the use of synthetic erythropoietin (r-EPO), that enhances erythropoiesis process.
The increased number of red blood cells transports more oxygen, thus raising oxygen levels in the tissues, particularly muscles.
Elevation of hematocrit above 55 % (hemoglobin>18) increases the risk for thrombotic stroke, pulmonary embolism or deep vein thrombosis.
Therefore athletes should use salicylic acid (aspirin), which has a thrombolytic-antiplatelet action, against blood coagulation.
The drug belongs to Non Steroid Anti-inflammatory Drugs (NSAIDs), that inhibit prostaglandins (PGs), through thromboxanes (TX) & cycloxygenase enzymes (COX1, COX2).
Aspirin’s action inactivates platelets’ activity, not their absolute number.
Since the white fast-twitch fibers involved in explosive sports (bodybuilding, sprints, shot put, javeling, weightlifting) are rich in glycogen and poor in myoglobin, the use of r-EPO is meaningless.
As a result, the increase of hematocrit and consequently hemoglobin-myoglobin, benefits the prolonged endurance events (marathon, cycling, triathlon).
However, some elite sprinters (Tim Montgomery, Marion Jones) claimed that r-EPO gave them improved recovery within training sessions.