Studies related to VO₂ Max and Iron

Marginal Iron Deficiency Without Anemia Impairs Aerobic Adaptation Among Previously Untrained Women

Effect Increase
Values Absolute. (L/min). Mean + SEM. Placebo: before 2.39 ± 0.11, after 2.56 ± 0.11. Iron: before, 2.11 ± 0.09 after 2.48 ± 0.08. Relative (mL · kg FFM⁻¹ · min⁻¹). Placebo: before 54.7 ± 2.2, after 58.1 ± 2.4 G. Iron: before 49.1 ± 2.0, after 57.6 ± 1.8.
Trial Design Randomized trial
Trial Length 1-6 months
Number of Subjects 41
Sex Female
Age Range 18-29, 30-44
Notes for this study:
In a randomized, double-blind, placebo-controlled trial, 41 women with marginal iron status (serum ferritin 8.07 ± 0.77 and 10.38 ± 0.82 mcg/L for placebo and iron groups at baseline) were assigned to take either 100 mg of ferrous sulfate (16 mg of iron) or placebo for 6 weeks. For weeks 3-6, the participants trained 5 days per week.

Supplementation notably increased mean ferritin, serum iron, and transferrin saturation, though not hemoglobin. Absolute and relativeVO2 max was increased somewhat more in the iron group, which was statistically significant, while the change in maximal respiratory exchange ratio and maximum heart rate wasn't significantly different.