Why Do I Retain Fluid on Long Rides

Question: How serious is “fluid retention” and what is the cause? Near the end of a tough two-week tour last year, my legs were quite swollen and took four or five days to go down (while my kidneys were working overtime). I drank lots of water each day. I’m leaving for another tour next month and would like to know how to avoid this problem. — Paul B.

Coach Fred Matheny Replies:  A common cause of fluid retention is not consuming enough sodium during long rides in the heat. In advanced cases, it can lead to hyponatremia, a serious medical condition. Copious water consumption, combined with heavy sweating, can dilute your body’s sodium content to a dangerously low level.

An easy solution is to salt your food or eat salty foods. Instead of plain water, use sports drinks containing sodium.

Gatorade and most other commercial drinks don’t have enough salt, so I often add a pinch to each bottle.