At this time the website is only available in English. The iOS app (iPhone and iPad) is available in German, Japanese, Portuguese, Russian, and Spanish and the Android app is available in Castilian Spanish, Latin Spanish, and Italian.
If you'd like to see TrainingPeaks translated into more languages please suggest it or vote on our feature request forum. If you enter your suggestion and your email address, you will be notified as updates are available on your topic.