Cobalt misuse in sports

Abstract

››Cobalt is a heavy metal, that was used between the 1940s and 1980s as a therapeutic agent to treat anemic diseases. Similar to hypoxia, cobalt stabilizes the HIFα subunits and stimulates the renal production of erythropoietin. ››For several decades, it has been suggested that cobalt is also used in sports to optimize oxygen transport via increased hemoglobin mass. In 2015, WADA put it in the list of banned substances. In various dietary supplements purporting to increase performance, cobalt was detected whilst incorrectly or not declared by the manufacturers. Our research suggests that an oral dose of 5mg/day exceeds the erythropoietic threshold. As a result, a 3-week supplementation period at this dose leads to an increase in Hb mass of 2% and to a tendency of higher performance, which corresponds to the effects of a training camp lasting 200h at 2000m. About 10% of the administered cobalt is absorbed by the body and excreted in urine with a half-life of 4-12 hours. ››In order to detect doping with cobalt, a reference limit of 14ng/ml in urine has been suggested, which is 4 standard deviations higher than the normal urine cobalt concentration. This value is clearly exceeded during and until one week after a 3-week supplementation period at 5 mg/day. Since it is possible that athletes use higher amounts of cobalt for doping purposes in hopes of achieving greater gains in performance, WADA must set appropriate reference limits and introduce regular test procedures to avoid serious health risks to these athletes.