I'm old & Out of shape

I played hockey last Thursday. Goalie for a street hockey open session. I'll be playing in the San Diego Floor Hockey League starting in January and am really looking forward to it, but its been at least 3 years since I've done anything remotely resembling athletic and playing in net uses a lot of abnormal muscles. So I'm hurting still (Its now Monday) and I'm not happy about it. Running, stretching, more time at the rink will certainly help the situation, but right now, I'm not happy about it.