I would love to give one of these a shot. I'm definitely not going to be good at it though, but I still think it would be fun to do. How long are the runs? Even in my prime about a 10 minute mile is all I could do. I was very fast at sprints but long range I sucked. I've never shot with a high heart rate either. So all of that being said I will not be good but I think I would still have a lot of fun. If you start another thread let tag me please so I can follow along.
The R&G is what you want it to be. You want to walk it? Great. You want to run it in a costume? Great. You want to look like GI Joe? Great. You want to wear gym shorts and a t-shirt? Great. Stop in the middle and eat Vienna Sausages and have coffee? Great. And if you want to try to compete to win, that's great to. This isn't USPSA where everyone shows up with professional fishing shirts and talk non-stop about how close they nailed power factor which is basically just code word for how can I make my centerfire weapon shoot like rimfire so I look cooler.
You should definitely just do it, you will love it and be welcomed regardless of your intent or skill set.