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I am 4' 11" and want to lose 20 lbs of fat and gain 5 lbs of muscle making a 15 lb total weight loss. When I burned 319 calories in 45 min on the treadmill last night I kept a runners pace between 5.5 and 6.0 for the most part. Occasionally I would pause for some water and then slow it down for a min and then speed it up to a real sprint at 6.5 just for a minute. I set the manual button for 40 min with the intention of doing a 5K (3.1 mile run). I finished my goal with a few minutes to spare and walked most of the 5 min cool down ending up at 3.5 miles done in 45 min. I have ran 5K's in the past and usually expect to cross the finish line in 40 - 45 min...when I really push myself, but the first 5 minutes on the treadmill or in a race is walking to warm up and then jogging at a slower pace, working uo to the 5.5 speed and gradually increasing to the 6.0 run.