Calculating weight change percentages are cumbersome. Scales vary, and no runner will be pulled or held up at aid stations who feels well and looks good for weight changes alone. The weight trend is helpful to figure out why a runner who feels terrible feels terrible. Based on research from WSER and other sources, our current guidelines for weight trend have been distilled down to this.
- Weight up, stop drinking until you pee off the excess.
- Weight down, drink.
- Mental status changes, drop and get medical help.