Iron is a nutritionally essential mineral required for optimal physical and cognitive performance. Endurance exercise often leads to declines in iron status; however, the reason for the decline is not known. The primary objective of the proposed study is to determine the effects of an acute bout of strenuous endurance exercise on iron absorption and status and markers of inflammation in human volunteers. The investigators hypothesize that an acute bout of strenuous endurance exercise, compared to rest, will reduce iron absorption, resulting in diminished iron status, and that reduced iron absorption will be negatively associated with markers of inflammation. A secondary objective is to monitor iron status throughout a season of competition.

Inclusion Criteria:

• Members of the Florida State University Cross Country team
• Refrain from using any pain-relievers (e.g., acetaminophen, nonsteroidal anti-inflammatory drugs such as aspirin, Advil®, Aleve®, Naprosyn®), or any other aspirin-containing product on the 2 study days
• Refrain from using vitamin or mineral supplements on the study days

Exclusion Criteria:

• Musculoskeletal injury that compromise the ability to exercise