I have followed 'Weight Training for Cyclists' for the last two off-seasons, it is a great mix of core, plyometrics and weight training all geared specifically towards cycling. I did not substitute the lifting plan for time on the trainer, but used it as an additional workout. If you do follow the plan that they layout in the book it will only take 30-45 minutes. I did notice improved overall fitness at the start of the race season, most noticeably a quicker jump and more power.