TrainingPeaks provides the complete web, mobile and desktop solution for enabling smart and effective endurance training. Our products include TrainingPeaks.com Athlete and Coach Edition, WKO+ desktop software for cutting-edge scientific analysis and planning, and the TrainingPeaks mobile apps for iOS and Android. TrainingPeaks solutions are used by Tour de France teams, IRONMAN® World Champions, Olympians, and age group athletes and coaches around the world to track, analyze and plan their training.
I use Training Peaks because it is the best online platform for planning, recording and analysing your training. Having used other services I have found that Training Peaks offers the best tools to help you have your best season yet.