I'm upping the ante on my training...I've been running for about 6 weeks now after about a 20 year layoff. I'm losing weight (down to 246 from 261 pounds) and getting my endurance up, I did two long runs in that time period, both between 2:45 and just under 3 hours for a half marathon distance. One was a treadmill run, and the other a very flat circuit course. I'm very week on hills so I am doing trail 5.1 mile trail runs several times a week with around 1600 feet of elevation and descent, and will soon work my way up to a regular sunday long run of 10.2 mile with 3200 in elevation and descent, then after a month or so I'll bump that up to 3 laps of the same trail circuit (15.3 miles and 4800 ft of elevation). I'm okay with the long run stuff cause its very slow, around 13:30 - 14:00 minutes per mile. But despite the build up in distance, I can't sustain a pace faster than 10:00 per mile for any distance at all, I'm just not strong enough yet, and that aspect of my running is not improving. So I am adding in some speed training. I did 10 x 120 meter 'sprints' on the grass infield over the weekend and felt great. I'll work that up to doing 16 of those sprints one day a week. I also want to do a track workout of high intensity 400 meters with one minute rest in between, probably 8 x 400...and then after a month or six weeks step those up to 8 x 800 meter at high intensity. I am carrying around an extra 70 pounds or so of dead weight, but assume I will get faster as the pounds wear off. My goal weight is about 175 pounds (I'm 6'2"). I want to run a barefoot marathon under 4 hours this fall, and under 3 hours next spring....with the ultimate goal of running 100 mile plus Ultras and being competitive in my age group. Is anyone here doing any 'speed' training barefoot? If so, what are your workouts and surfaces?