I run and lift. On occasion I throw a couple of bike rides in but that's rare. I found I was at my leanest when I threw in some walking on rest days. I would walk fast on a trail for about 4.5 miles. I noticed the fat just pouring off. Walking fast is seriously an under rated exercise.
Woo, what are you running a 5K in? When I was young I could string together sub 6 minute miles but now I'm old and broken down. My body just doesn't respond to training anymore like it use to. I got a charity 5k tomorrow and I will be lucky to do 7 something minute miles. I'm just glad to be able to run in my mid 50's. Hopefully by spring I will get back some endurance and run some decent times. Training for this race I went from 187 to 177. If I can drop another 10 I should be flying for an old goat.