A rule of thumb I use is that you can (should) only train one stimulus a day.
Have your pick: speed, endurance, or heat. If you try to combine more than one, that's where you start compounding fatigue. If it's hot out, keep it in zone 2.
If its hot out, I just move any intervals to another day, earlier in the day when it's cooler, or inside on the treadmill.
Have your pick: speed, endurance, or heat. If you try to combine more than one, that's where you start compounding fatigue. If it's hot out, keep it in zone 2.
If its hot out, I just move any intervals to another day, earlier in the day when it's cooler, or inside on the treadmill.