I also don't rate treadmills; don't think they're the same as running for real.
I do nearly all my intervals on the roads or in parks and have done for years (occasional track work to sharpen up, being the rest).I often do sessions on the way home, usually fartlek as you don't have to stick to particular length reps with that, but I do make sure I get a more regimented session once a week, usually on a quiet road loop now it's dark early.
I also don't rate treadmills; don't think they're the same as running for real.
I do nearly all my intervals on the roads or in parks and have done for years (occasional track work to sharpen up, being the rest).I often do sessions on the way home, usually fartlek as you don't have to stick to particular length reps with that, but I do make sure I get a more regimented session once a week, usually on a quiet road loop now it's dark early.