Hydration baseline
Hydration by
Body Weight
Body weight gives a useful starting point, but the final hydration plan still has to respect heat, sweat rate, and session length.
Normal dayPractice add-onBottle planCheck the trend
Baseline target
Start with
Add on top
Practice loss
Bottle plan
Make it real
Trend, not hype
Check
Start here
Set the normal-day baseline. Add workout losses separately. Split it into bottles. Check the trend.
When the baseline is not enough
- Hot or longer practice Treat the workout loss as extra instead of pretending the normal-day target will cover it.
- Big end-of-day catch-up The problem is usually the earlier bottle plan, not a lack of willpower at dinner.
- Heavy sweater or repeated cramps Review sweat loss and sodium planning instead of just pushing more plain water.
Build the bottle plan
Baseline
set the normal-day target first
Training
add practice loss separately when heat or session length rises
Bottles
split the total across real refill points
Trend
use urine color and body feel to keep the baseline honest
Where the math breaks
A body-weight formula is a starting point, not a competition.Heavy drinkers still need sodium planning when sessions run long and hot.Big end-of-day catch-up usually means the earlier plan never became real.
Ask whether the athlete is missing the normal-day baseline, the workout replacement, or both.