So here is a question for those health experts: other than training for a specific event / distance, is there any benefit to running longer than 45 mins? (assuming it's a hard 45 minutes). I keep hearing and reading about the lack of benefits from "low and slow" excercise, how it just burns muscle.
I am making the assumption that trail running on the north shore has enough variation, elevation etc… that it qualifies for interval training than say running a flat road?
So what does running said north shore trails for 1.5+ hours do for you?
My long term goal is general health, not worrying to much about looks, physique etc…
it really depends on what benefits you're after. if all you want is improved CV conditioning then it's been shown that 15 minute HIIT or tabatas will provide as much benefit as a 10k run. what the shorter workouts won't provide though is the soft tissue conditioning (muscles, connective tissue, etc.) to run long distances. and yes long endurance training is catabolic, so it does "burn muscle." so running the trails for 1.5 hrs will help improve your CV fitness and muscular endurance as well as improve things like agility and co-ordination to a degree. and in some hard charging hills or sprints and you can also work on speed and power to a degree as well. it would also good for your mental well being (emotionally and intellectualy). the drawback is potential knee issues and possible sprains to particularly the ankles if you mis-step while running on uneven terrain.
the key thing with any fintess prorgram is to determine what your goals and expectations are and then find an activity to fulfill those goals that you also enjoy doing.