Yes i does!! Outside your feet will move in different places, Rocks, gravel, grass, pavement ect... therefore you not only working you legs and everything you are now working, legs arm, feet, ankle (will be more supportive) and will get you to think where your running so also your brain. A treadmill you are running in one place and WILL NOT see the same impact on a treadmill!!! In other words, if you want a better work out, run outside!!!
yes. try holding about 3 to 5 lbs in each hand and pumping them up and down. do reps of 30 secs with ten seconds between. breath in your nose and out your mouth. it's an excellent cardio and endurance exercise.