Effect of intravenous iron substitution (iron carboxymaltose (Ferinject®), total dose 15 mg/ kg (maximal dose: 1000mg) in 250 ml 0.9 % NaCl; intravenous infusion in 20 min)in non-anemic premenopausal women with iron deficiency on

Primary objective:

- Mitochondrial capacity (Phosphocreatine Recovery rate assessed by 31P-MR-spectroscopy of the lower leg muscle)

Secondary objectives:

• Maximal oxygen uptake during a graded cycling exercise test and time to exhaustion at submaximal power during a constant-load cycling exercise test
• Plantarflexor muscle fatiguability as assessed by isokinetic dynamometry
• Trial with medicinal product

Inclusion criteria: INCLUSION CRITERIA

• Healthy female subjects, Age > 18 years, premenopausal, regularly menstruating
• BMI 18-25 kg/m2.
• Serum ferritin level < 15ug/ml
• Recreationally active with = 1.5 h/w structured activity
• Adequate contraception during the study period
• Informed consent

Exclusion criteria: EXCLUSION CRITERIA

• Anemia with Hb level < 120 g/l
• Known hypersensitivity to iron carboxymaltose, iron sucrose or iron sulfate
• Intake of iron preparations (also multivitamins containing iron) during the last 8 weeks before the start of the trial protocol
• Pregnancy or lactation
• Any cardiovascular or pulmonary disease
• Any orthopaedic or rheumatologic disease which affects exercise performance
• Presence of muscle disease
• Acute or chronic infection/inflammation or malignancy
• Known mental disorders (e.g. depression)
• Intake of concurrent medication, except oral contraceptives
• CRP > 10 mg/l
• TSH out of normal range
• Elevated CK (> 167 U/l)
• Any concurrent medical condition(s) that, in the view of the investigator, would prevent compliance or participation or jeopardize the health of the patients.
• Participation in any other therapeutic trial within the previous month