I've not been out running now for three weeks due to the heat. I find I just can't breathe when it's like this so I really struggle. Anyway, with rain & storms on the way this week I'm desperate to get back out there. Will it be hard to get back into it, do you know? Will I find it really tough? Before I took a break, I was running 5k in 28 mins if that helps. Any advice gratefully received.