Work performance in the iron-deficient rat: improved endurance with exercise training.

Area of Science:

• Exercise Physiology
• Nutritional Biochemistry

Background:

• Iron deficiency anemia (IDA) impairs athletic performance.
• The impact of exercise training on muscle adaptations in IDA is not fully understood.

Purpose of the Study:

• To investigate the effects of endurance training on muscle oxidative enzymes and work performance in iron-deficient rats.
• To compare these effects with those in iron-sufficient rats.

Main Methods:

• Male Sprague-Dawley rats were fed either an iron-deficient (6 mg/kg) or iron-sufficient (50 mg/kg) diet.
• After 2 weeks, rats were assigned to untrained or endurance-trained subgroups.
• Training involved daily treadmill running for 1 month; muscle oxidative enzymes and work performance were assessed.

Main Results:

• Iron-deficient rats developed anemia (Hgb ~8 g/dl) and had lower muscle cytochrome c, cytochrome oxidase, and succinic oxidase activity.
• Endurance training significantly increased muscle oxidative enzymes in iron-deficient rats, unlike iron-sufficient rats.
• Work performance in iron-deficient rats improved over sixfold with training, while maximal oxygen consumption was unaffected.

Conclusions:

• Endurance training in iron-deficient rats mitigates anemia severity and preserves muscle oxidative enzyme function.
• This adaptation allows for significant improvements in endurance exercise performance despite iron deficiency.