Ready for mtb racing?

There's a mountain bike race coming soon just around the corner coming this Saturday 31st Oct, i've done registering myself for the race participation. Got few rival from Brunei, Bintulu city and other district which known to have fast competitors. However i haven't been racing for 2 year now. Wonder if i should push myself physically to the limit or just stay cool behind the pack. My mental always say "Yes you can handle it!" but my muscles "Nay!" cause my age seem to depreciate overal performance of my body. After peering into collection of medals and thropy inside the cupboard that i won in the pass few years ago i was wondering...man i do feel old now. Somehow the best i can do is finish the race regardless what position.