Which supplement can lead to a decline in performance and may be ineffective in raising hemoglobin concentrations? a. creatine b. coenzyme q10 c. iron d. pyruvate

Iron supplements may be used in treating anemia and is commonly used by athletes. However, the kind of anemia that athletes experience is a little different because it tends to be exercise-induced due to their heavy training. In this case, iron may be ineffective in raising hemoglobin concentrations because of the exercise-induced decrease in iron absorption.