I don't compete at the moment, but I've done competition diets before. Usually my cardio was like yours. Incline treadmill, 45min am and 30-45min PM. Walk on an incline. Sometimes I'd switch it up with the bike or the elliptical. Lately though, I've been doing some sprints the last 10 minutes or so. I put the incline down to 0 and walk at 3.2mph. Then I "sprint" at 7mph or so for 30-45seconds, then back down to 3.2 for 1.25-1.5 minutes. I do 4-5 of these, and then cool down. Helps the time go by. I'm not sure if that helps either, but since it's not constant running I don't think it hurts my legs. Also, I don't do these before or ON leg-day, just the other 3 days I do cardio.