I use whey protein on a regular basis and I find it helps. I ride my trainer in the morning before work and then take in a shake made with whey and frozen fruit. I definitley notice a difference in recovery (whether it be lifting or riding) when I take in some protein supplements. I buy it in bulk, I used to get EAS or Designer Protein in a 6 lbs tub but now Im on a tighter budget and get the Costco version for 20, the others were around 30.