What is more beneficial when running to improve cardio?

[BrotherHarsh]

I like to constantly mix it up. Old fashioned road work. Run trails. Sprinting on a field or wherever. Sprint steep hills. Never let your body adapt and always put yourself in an uncomfortable place. Overcome it mentally as well. I think you can train as much as you want as long as you are eating right and taking your vitamins for recovery. Sleep and recovery are key to training. Just my thoughts on it.

[Andre]

Just looking at the heading, I'd say having someone after you with an axe

[Scrap]

Too much Stress Andre