Back pain (herniated disc/back spasms/sciatica) has kept me off my bike for 2 weeks now and probably will for at least one more. However I want to ride the 70 mile Tour De Scottsdale on October 4th. What's the best way to train without being able to ride or hit the gym? Right now I can swim, but do you have any tips on what type of swimming (strokes, reps, speed, etc...) can help me on the bike?
In other words, I'm starting to panic as I feel I won't be able to get my fitness level up in order to ride 70 miles with plenty of hills. Before my back injury I was riding 10-20-35 miles and my previous high is 40 miles. Any help you can give me to get me across the finish line would be much appreciated.