Iron Bisglycinate provides an optimal way to supplement iron, which is essential for red blood cell formation. It helps fight fatigue and other symptoms of iron deficiency in athletes and others. NSF Certified for Sport.Thorne’s Iron Bisglycinate is NSF Certified for Sport. It is essential for the formation of red blood cells. The U.S. Centers for Disease Control has determined that the prevalence of iron deficiency is greatest among toddlers (7% of those ages 1-2 years) and menstruating adolescent and adult females (9-16 % of individuals ages 12-49, whether they are athletes or not.