The heat and humidity definitely take a toll on HR. Living in Miami and trying to get my runs in at lunch time (90's ++), yes it makes a huge difference.
However, it preps you for race day since you will be riding and running in similar temps.
H...
Hey mike, training (week 6 of ultra) for my first ironman in October (Great Floridian), and got a big bug from my kids. Have had to slow down due to fever, nausea etc... should I repeat the week or continue as niormal? Thanks for all your help. BT...