Monitor your heartrate
Your heartrate shouldn’t be going up by more than about 10 beats per minute from what it would typically be on an easy day. If it stays consistently higher, you may be entering a dehydrated state.
Slow down to finish the session
Most of the time, it makes more sense to slow down and get the entire run in, rather than cut it short because of the heat. Only stop short of your target distance if you experience severe cramping, dizziness or nausea, which are the warning signs of heatstroke.
Listen to your hamstrings
In most runners the first sign of dehydration is evident in the hamstrings. So pay close attention on longer runs. If your hammies start getting tighter than usual; this is a good signal you’re not taking in enough electrolyte fluids.
Stretch before you head to bed
The last thing most people want to do when they feel the panic of trying to cool down after a hot run is diligently work through their post-run stretching routine. So do it before bed – when you should be well hydrated, and your muscles will still be warm.
Time your drinking
It takes 20 minutes to absorb fluid prior to exercise, and drinking large amounts quickly before you head out the door will only cause your system to flush out that fluid rather than absorb it properly. Nursing it over a 30-minute period is optimal before you hit the road.
