| Inside Triathlon | | Calendar, race coverage, training tips, links, and a message area. |
| Insideout Sports | | Information on triathlon in the Southeastern US, an online retail catalog, a used bike bulletin board, and a detailed race calendar for selected events. |
| Isherwood Coaching | | Ex-professional Triathlete and Duathlete Kim Isherwood help get the best physiological condition possible and improves race performance. |
| Just Racing | | Organisers of Triathlon and Multi Sport events in the UK. |
| MacPanda - Lardy to Lean | | One mans quest to become significantly smaller and fitter, whilst fulfilling the long held desire to complete a triathlon. |
| Proathlon.hu | | Triathlon and multisport news and photos from around the world. Including Hungarian athletes homepages as well as an online shop. [English, Maygar] |
| Set-up Inc. | | Triathlon and Duathlon race production services. Race directing, set-up, and computerized timing and results. Site also contains race information, results, coaching and nutrition advice. |
| The Triathlon Experience | | Ironman Racing in Austria, Switzerland, Germany. Destination Triathlons in the United States and Europe. |
| Tri-Newbies Online | | Information based source for new triathletes. Featuring an active triathlon discussion forum, articles, variety of specific sections, online coaching services, weight training, heart rate monitoring resources and news. |
| Triathlon Central | | Results and current Olympic qualification standings, as well as information on signing up for the daily email Triathlon Digest, and annual Triathlon Sourcebook. |
| Triathlon Gold | | Bill Davoren's online source for all triathletes from age-groupers to pros from sprint to ironman. Many articles to read plus information on coaching services and camps and clinics. |
| Triathlon Results | | This site allows users to interactively compare their triathlon race results with other racers, and even chart their performances over time. | |
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