I'm 46 and have been running/joggin 3-5 miles 3 times a week for 23 years very consistently. For the last 10 months I've been jogging for 40 minutes (about 4.2 miles) up and down hills. I never go more than 2 monutes without going up a hill for at least 1-3 minutes--some are very steep but fairly short. Should I change my length as far as going less time and or just change the whole thing some? I fell like I get a lot out of the run as far as cardio. When I get done my HR is around 150-160 because of all the hills I guess. My HR usually goes back to 90-100 within a 2-3 minutes after stopping and walking and then 80-90 within 5 minutes of stopping running.
Sorry, I just run/jog for health reasons. My problem is (I think) if something works I just keep doing it until I've probably overworked it! Sometimes the run is much harder than other times. My diet is very consistent so it's not that. I have this mental block that if I don't go at least 40 minutes then it's not as good as if I do. I know---stupid.
Sounds like you should just keep doing what you're doing. Fact of life, some days are easy, some are hard, and some just flat out suck; even the best runners in the world have days they'd like to soon forget.