This is the weekend that you know it's really getting serious and the season has well and truly started. While we have the ITU Triathlon World Championships in Vancouver occupying the bulk of the attention and the Eagleman 70.3 race in Cambridge, Maryland as the overseas contributors there's more than enough on the home front to keep everyone busy. Don't forget that you can get live timing and finish line video from Vanvouver on the ITU website (www.triathlon.org) for the age group sprint race on Friday and the standard distance on Saturday plus there's full coverage of the elite races on Sunday. The IronmanLive site (www.ironmanlive.com) will be providing athlete tracking for the Eagleman 70.3

Biggest of all the events has to be the Mazda Blenheim Triathlon where there's two days of racing in the stunning grounds of Blenheim Palace in Oxfordshire. The majority of the competitors will be there for a bit of fun but the serious stuff is on the Sunday monrning where the elite wave includes Stuart Hayes and is usually pretty fast and furious. If you are racing there remember to brush up on the details in our How to Succeed at... feature.

Saturday's racing includes two aquathlons; the NUTS Summer Aquathlon in Nottingham and the second OWS Aquathlon at Liquid Leisure's lake in Datchet. There's even a duathlon, the Tan Hill Duathlon which takes in the highest inn in the country (and try typing that after a couple...)

Sunday features a trio of longer distance races, the Bala Middle Distance, the Weymouth Middle Distance (which also has a sprint distance race as support) and the Soll Vale Ultra which covers 1.6k swimming, 70k biking and 17k running and so isn't quite as ultra as the name suggests.

There are a number of multi-event races happening on Sunday: at Arundel we have a 'long' event (800m/40k/10k) with supporting relay, sprint and junior races. At Tatton there's a standard and a sprint while Fritton Lake sees a standard and a sprint triathlon and a junior aquathlon.

Other racing includes sprint distance events at Cosmeston, Peebles, Wantage and Inverurie. Supersprint racing takes place at the Cannon St Albans Triathlon, the Trisports Bedford Series, Rossendale and Grantham. TriFerris are running their Women Only races at the Cotswold Water Park and there's also a Long Swim at the same venue.