If its the only ride your doing each week, you're gonna be tired. My belief is 3 rides per week minimus to build up... not all 3 need to be 50 miles long, but your body isn't getting "stressed" enough to improve. Instead, you are "resting" yourself back to square one.

If you rode like 20 on Tues & Thurs, then your 50 on Sat you'd probably start noticing a difference. Add an easy 10 on Sunday to flush out the lactic acid and warm any kinks and you'll be golden.

Who do you ride with (i.e. which club)?

spazz