Monte Warden knew it was time to lose weight when he had this epiphany: “I woke up one day and there was a fat drunk in the mirror, and he was screwing my wife.”

The Austin-based songwriter can laugh about it now, because he’s essentially turned his life around. Still, he keeps a photo nearby, taken in 2003, when he was 50 pounds overweight. “That’s the picture that started it all,” he says. “That’s horrible. … It was a long time ago. I had just quit taking pills and quit drinking. I thought I was about 20 pounds overweight, but you step on a scale and you go, ‘F—! I am 50 pounds overweight!’ I had to do something, so I did.”

Warden started by running short distances, and relied on his singer’s lungs to build his endurance. His biggest piece of advice to new runners is to avoid comparing themselves to other runners on the trail. “You say, ‘I’m going to run a mile today,’ and you try, and then you say, ‘I’m going to run 10 yards today.’ The first thing I did, I guess I ran half a mile, and I realized that half a mile is pretty far. Then you run a mile, and I was at a mile for a little while. Once I broke past one mile, I could run five miles. It was the first mile that just about killed me.”

Since he’s been running, almost always in the mornings, Warden’s been on a roll. He’s completely sober and 50 pounds lighter. When he travels, he still makes it a point to run, even in London. “I think about the other things I used to chase down in cities around the world…” he muses. At 40 years old, Warden imagines easily fitting into the stage clothes he wore in his 20s, when he was leading the progressive country band, The Wagoneers. In 2004, George Strait released “Desperately,” a Warden co-write with Bruce Robison. He’s working on new music too, and running a publishing company with his wife, Brandi, who ran the Country Music Half-Marathon with him last year. In April, he’s going for the full, 26.2-mile distance, and the fat drunk in the mirror will be nowhere in sight.