Good questions and very pertinent since the weather has changed significantly recently.
First off, as you are finding there is no magic pill here. Between the heat, humidity and pollen, it’s been a trying few weeks. And it does take several weeks to actually ‘acclimate.’ One way to help with the acclimation process is to actually do some heat training. While it’s never fun, it does help.
While doing so, you need to adjust your run/walk, as you are doing. The #1 factor you must attend to while adjusting/scaling your run:walk patterns is to ensure you are staying in your appropriate HR zone/target (during the run segment) and consciously work or ‘train’ your HR to come back down during the walk segment. You need it to come down as low as possible to help keep your body from overheating and ward off HR drift as much as possible. It’s all about keeping your body heat and HR as well managed as possible.
You hit on the other necessary area. Nutrition! You will always be in a caloric and hydration deficit throughout training and racing. Thus this is why you need to find the maximum you can get in without GI issues. If you are a heavy sweater, you need to keep increasing your volume as much as you can. For the most part, this should be sports drink since you need to electrolytes (and minimize water to avoid hyponatremia). How many electrolytes are you getting in per hour? This may be a very integral data point that needs to be continually manipulated until you find the right needs for you in the hot and humid weather. You need full electrolyte stores in order to absorb any fluids you take in, water or sports drink.
It sounds like you are working hard in this area. Keep up the good work!
