At some point in your triathlon career you are going to pick up an injury. It could be anything from Wetsuit Chafing to Blisters to Metatarsal Stress Fractures. Some injuries you will just have to accept as a given but the vast majority you can overcome with proper training and planning.
Make sure that your trainers fit correctly. You instantly know if they don't feel right and the mistake to avoid is ignoring it because it is one problem that won't go away. Rather than buying the latest or most popular model on the market go to a specific running shop and have them measure your feet and assess your running style to ensure that you are getting the right shoe for your foot otherwise you could end up like the poor guy pictured!!
2. Getting smacked at the swim start - A mass start is never a particularly pretty affair and bruises, scratches and black eyes are commonplace from flailing hands, elbows and legs.
The best way to stay out of harms way is to find a clear bit of water or stay on the outskirts of the pack. If the swim is your weakest event then don't try to get caught up in the masses when the gun goes, instead hold back for one or two minutes. In the grand scheme of things you won't have lost must in the way of time and you will exit the water calmer and ready to face the bike as you will of had a injury free swim!!
3. Shin splints - Shins splints are an aching or throbbing pain in the front of the leg. They usually get worse while you run.
In general, shin splints are cause by one of two problems: increasing your running mileage too quickly or faulty bio-mechanics. Having one leg longer than the other or over-striding are common causes. Running on concrete surfaces or hills can also lead to shin splints. Always tell your coach if you think you are getting shin splints and make sure that you ease off the running for a short time to allow your legs to adjust.
4. Sunburn - If you train and compete solely in the UK then it is very unlikely that you will have experienced a tan line and sunburn!! If, however you live, train or compete in warm climates then sunburn and sunstroke are major factors which need to be taken into account.
If you put suncream on before the start of the race it has usually come off by the time you exit the water and applying suncream isn't usually at the forefront of your mind when out on the course. For some events teams of volunteers will apply suncream for you in the transition areas but if you are ever in any doubt about the strengh of the heat then cover up. Wear compression socks on your legs or forearms or wear a long sleeve jersey for the bike and run. It may not be the coolest thing to do (and I know how important image is !!) but its better than alternative which is a substantial drop in performance during the race due to sunburn/sunstroke.
5. Illio-Tibea Band Syndrome - Illio-tibial band syndrome (ITBS) is probably the most common cause of knee pain in triathletes. ITBS happens when the thick band of tissue along the outside of your leg pops back and forth across a bump at the outside of the knee. This leads to inflammation and pain. Discuss your running shoes, running style and the surfaces you run on with your coach and together you might find a simple cure. The alternative is to work on a number of knee strengthening exercises.