1 month fitness boost!

dr crash
dr crash Posts: 53
edited February 2011 in Health, fitness & training
Hi all ,
Iv'e got one month before my bucs student xc race and forgot just how unfit i am!
Anyone got any tips on how best to increase stamina and fitness quickly?? I'd normally just do one long ride (20-30) miles every 3 days and try and build in a few big hills, but is it better to more rides at a lower intensity??
any help would be much appreciated!