Triathlon Guide
Triathlons are endurance races that combine swimming, cycling and running into a single event. According to the International Triathlon Union, the first officially recorded triathlon took place in San Diego in 1974. In the years since, the sport has grown steadily, culminating with the first-ever Olympic triathlon at the 2000 Sydney Games. Today, events are held all over the globe. Whether you’re interested in learning more about triathlons or you’ve already started training for your first event, this guide is designed to cover every aspect of the sport, from clothing and gear to triathlon rules and tips.
  • All triathlons consist of three stages completed in order: swimming, cycling and running. The four most popular types of triathlons are Sprint, Olympic, Half-Ironman and Ironman. If you’ve never participated in a triathlon before, it’s probably a good idea to start with a sprint first (the shortest of the four) and work your way up to more challenging events.

    Race Type Swim Distance Bike Distance Run Distance
    Sprint 0.465 mile (750m) 12.4 miles (20k) 3.1 miles (5k)
    Olympic 0.93 mile (1.5k) 24.8 miles (40k) 6.2 miles (10k)
    Half-Ironman 1.2 miles (1.9k) 56 miles (90k) 13.1 miles (21.1k)
    Ironman 2.4 miles (3.8k) 112 miles (180k) 26.2 miles (42.2k)
  • Swim Stage

    In all modern triathlons, the swim leg is first. Wearing the right apparel is essential to your comfort level for the duration of the event. On that note, any clothing changes will have to be made in public, which means you’ll be wearing the same base layer from beginning to end. For men, this is usually a pair of tri shorts or a full tri suit. For women, it may be tri shorts and a sports bra, a tri suit or a one-piece swimsuit. Whether or not you’ll need a wetsuit depends on the water temperature.


    For women, a competition swimsuit is ideal for training and events in very warm weather. Competition swimsuits are made of durable, high-performance materials that are treated for chlorine resistance. These suits are always one-piece, and typically feature higher necklines and non-slip racerback straps. Competition swimsuits for men are typically briefs. Although you can wear a swimsuit to the race and simply layer a pair of bike shorts and a jersey over your swimsuit, most athletes prefer to wear a tri suit.

    Tri Suits

    Triathlon suits, or tri suits, essentially combine all of the clothing you would normally need during a triathlon into one moisture-wicking, quick-drying, full-coverage garment that can be worn underneath a wetsuit. Tri suits come in one-piece or two-piece styles. The tops are typically sleeveless and the bottoms feature a low-profile, quick-drying chamois pad that is more comfortable than a full cycling pad during the swimming and running portions of the race. Women’s tri suits usually feature a built-in shelf bra, although some women may still prefer to wear a sports bra underneath for additional support.

    Triathlon Wetsuits

    If the swim portion is outdoors in water that is below 75°F, you’ll likely be more comfortable in a wetsuit. A wetsuit will not only insulate your body from the cold, it will also provide a small amount of added buoyancy. Most triathlon wetsuits are either short sleeved or sleeveless and have full legs, although full-sleeved varieties are available for colder conditions. Triathlon wetsuits tend to be thinner and much more flexible than suits designed for diving. Wetsuits are sized according to gender and a variety of height and weight ranges. Wetsuits generally have enough stretch to fit a frame that falls slightly outside the recommended height or weight guidelines. For more on sizing and other info, check out our Wetsuit Guide.

  • Bike Stage

    Because most of the race distance will be covered on your bike, you'll want to be as comfortable as possible in the saddle. The two most important considerations are finding a bike that fits your body and wearing apparel that will keep you comfortable in whatever conditions you’ll be riding in. Most triathlon apparel is designed to dry quickly, allowing you to transition from water to bike to run without changing your base layer. Although you can certainly ride in your tri suit or swimsuit during the race, you will still need cycling-specific clothing for your training sessions. If the event is taking place on a chilly or overcast day, you may need additional coverage during the cycling portion to stay warm.

    Cycling Jerseys

    All cycling jerseys are made of breathable, moisture-wicking fabrics that will help keep you dry and comfortable. They are cut with an extended rear hem for coverage and often feature a long front zipper for adjustable ventilation. Choose a bike jersey that best fits your usual training conditions. If you plan on participating in a triathlon during chilly weather, you can layer a long-sleeved bike jersey or wind jacket over your tri suit during the cycling stage and remove it before the running stage. Arm warmers and leg warmers are also good, lightweight options for chilly weather. For a full breakdown of cycling apparel, check out our Cycling Gear Guide.

    Bike Shorts and Tri Shorts

    A pair of bike shorts is probably the most important cycling garment you will buy. Bike shorts are typically made from a Lycra® blend and have a moisture-wicking, padded chamois for enhanced comfort in the saddle. The close-fitting fabric reduces the chances of abrasion and chafing. Tri shorts are essentially a specific style of cycling shorts that have a smaller, less bulky chamois pad, which allows them to dry more quickly during the transition from water to road.

    Cycling Shoes

    Although some brands make triathlon-specific cycling shoes, most road cycling shoes will be appropriate, assuming you’re using clipless pedals. Cycling shoes with hook-and-loop straps are ideal for speedy transitions. If your shoes have laces underneath the straps, simply remove them before your race. You won’t need them. Check out our Bike Shoe Guide for more information on cycling shoes and clipless pedals.

    Bike Helmet

    Wearing a cycling helmet during the bike stage is mandatory in most triathlon events. Lightweight, aerodynamic road bike helmets are ideal, as they offer multiple cooling air vents. If you’re cycling in colder weather, an ear-covering headband is also a good accessory to include. Tip: It’s important to have your chin strap securely buckled before mounting the bike. If a race official notices that you haven’t buckled your strap, they may detain you until you’ve secured it.

  • Run Stage

    Triathletes will complete the running portion in the same base layer they’ve been wearing since the beginning of the race. A one-piece or two piece tri suit should provide all the coverage you need for running in warm weather. Women who choose to wear a one-piece swimsuit as their base layer may prefer to quickly slip on a pair of running shorts. If the weather is chilly, arm warmers and leg warmers may be added. For very chilly weather, you may want to spend a few extra moments putting on a set of running pants, a long-sleeved top and a light beanie or headband. Being too cold usually won’t improve your time. Look for running gear with integrated reflectors so you can train safely any time, day or night. For the event, be sure you have a place to store an energy gel or two. Chances are you’ll need a boost of nutrition during the cycling and running stages.

    Running Shoes

    Although your standard pair of running shoes should be perfectly sufficient, brands like Zoot Sports and Asics offer triathlon-specific running shoes. Most tri shoes feature quick-pull lacing or a slip-on design to shave a few seconds off of the second transition. However, the most important thing is to choose a pair of running shoes that are comfortable and broken-in. It’s definitely not a good idea to wear a brand new pair during an event. Check out our Running Shoe Guide for more information.


    A lightweight, low-profile pair of running socks is ideal for the running portion of the race. Obviously it’s important to avoid cotton socks, which don’t wick or breathe as well as synthetic and wool socks. For shorter races, some athletes skip socks during both the cycling and running stages. For longer events, you’re probably better off spending a few extra seconds putting on socks, unless your feet are well-accustomed to running without.

  • Triathlon Gear

    Water Bottle

    Whether you're training or racing, you’ll definitely need hydration. Aside from the bottles on your bike, you should also have a small bottle at the second transition so you can get a quick drink before beginning the running stage.


    A pair of lightweight sport sunglasses will not only block harsh UV rays, they will also protect your eyes from bugs and debris during the cycling stage. To save time, tape your sunglasses to the handlebars or secure them to your helmet so you can put them on once you’re in the saddle.

    Swim Goggles and Cap

    Although not all triathletes wear swim goggles, many do. If you wear contacts or have sensitive eyes, goggles are strongly recommended. A swim cap is also highly recommended, especially if you have long hair.

    Bike Gloves

    Although most triathletes don’t wear bike gloves during shorter races, you’ll likely want them for training rides, longer races and colder weather. Padded cycling gloves can also really take the edge off long-distance rides.

    Aero Bars

    Adding a set of aero bars to your bike will provide you with an alternative riding position, allowing you to switch things up if you start to become uncomfortable. Some cyclists actually prefer using aerobars over drop bars, although it’s strictly a matter of personal preference. If you do add aerobars, be sure to practice riding with them before the race.

    Bike Computer or Training App

    A bike computer can be an excellent training tool, allowing you to easily track time and distance traveled. Most smartphones have access to mobile apps that can use GPS to track your distance, elevation changes, split time and much more. This can be a big help during training.

    Watch and Heart Rate Monitor

    Besides keeping track of time, many sport watches can track your mileage during runs. A heart rate monitor can also be used to help you stay within your target heart rate zone for optimal training.

    Hat or Visor

    A lightweight cap or visor will keep the sun out of your eyes during the running stage. Just make sure it's made of a lightweight, breathable material.


    Having a small, absorbent towel to wipe your feet after the swim stage can be very helpful. You may consider having another small sport towel at the second transition to wipe your face and brow before hitting the run.

    Anti-Chafe Balm

    Body balms can be applied to specific areas inside your tri suit and wetsuit that are prone to causing chafing and abrasion. You can also apply anti-chafe balm to the back collars of your shoes, making it easier to get your feet in and out, should you choose not to wear socks.

    Gear Bag

    You need something to carry all your stuff to the transition area. Some athletes use a small satchel for their cycling gear and a separate small bag for their running gear.

  • Triathlon Rules

    Depending on the event, triathlon rules can vary. However, there are many universal conduct rules that every triathlete should follow, whether you’re at the Ironman World Championship or a local event. If you’re racing in the US, consider reading through the USAT Rule Book. Most triathlon rules are simply common sense. Penalties for offenses vary, depending on course length and the event. At most races, a third infraction will result in disqualification, and race staff will be watching participants closely. To give you an idea of what to expect, we’ve overviewed the more clear-cut conduct rules here:

    1. Practice good sportsmanship. Treat others with respect and don’t use excessive profanity. Don’t shove or intentionally impede another athlete. Of course, accidentally bumping into other racers can happen, especially during the frequently congested swimming stage. Do your best to be a good sport, and you should be fine.
    2. No nudity. This should go without saying, but you can’t strip down to your birthday suit in public. Determine a layering and changing strategy before the race.
    3. Keep track of your stuff. Don’t drop anything, such as a power gel container or empty bottle, and don’t leave anything lying on the course. The event rules should clearly describe what to do when you change gear during stage transitions.
    4. Leave the earbuds at home. All USAT-sanctioned races disallow personal electronics during a race. Athletes are also forbidden from using any glass containers. Read the race rules carefully to learn about any other prohibited equipment.
    5. Get to know the course. Any deviation from the course, even accidental, may result in a penalty, so it’s important to familiarize yourself with the course ahead of time, if possible. Course deviation includes swimming on the wrong side of buoys, so pay special attention during the swimming stage.
    6. Be aware of making a temporary exit. If you leave the course for any reason, you must return at the exact point where you left, or you could get hit with a penalty.
    7. You’re on your own. You cannot accept any unauthorized assistance during a race from spectators, which includes water, food, a new inner tube for your bike... you get the idea. If you need something, you should be able to get it from an aid station. Event volunteers should also be spread out over the course to provide assistance to athletes.
    8. Display your number. Make sure your race number is displayed appropriately. Ask a race official for the particular rules displaying race numbers. Typically, you’ll have a number displayed on your bike in addition to somewhere on your body during the run. Many athletes attach their number to a thin, quick-release belt, making it easier to put on during the second transition.
    9. Take note of mount and dismount lines. After you get into your cycling gear, you’ll need to walk your bike to the mount line. In the second transition area, make sure you don’t blow past the dismount zone, which could incur a penalty.
    10. No drafting. Don’t intentionally draft another participant. Basically, don’t get near another athlete unless you’re passing. When you pass, do it on the left, do it quickly and then get back over to the right as soon as it’s safely possible.

    *Note: These rules are not comprehensive. Specific race rules may vary.

  • Triathlon Tips

    Newbie triathletes sometimes see the transition area as a place to slow down and get collected before the next stage. The sense of urgency can easily diminish in the transition area, especially in larger races where food, drinks, sunscreen and friendly volunteers can create goal-breaking distractions. In a sprint or Olympic length event, slow transitions could mean the difference between 29th place and 35th. Transitions become slightly less critical in a half or full Ironman, but speed is still extremely important.

    Think about how many hours of training it requires to reduce your average mile time by a fraction of a minute. Shaving a full minute or more from your overall transition time may only require a handful of changes and practice. Remember, transitions aren’t about recuperating from your last leg. They're about changing your race perspective, both physically and psychologically, in the most energy-efficient way possible.

    Plan and Practice

    Plan exactly what you’ll do between stages, including how you pack your gear. It’s extremely helpful to physically rehearse your transitions until you feel comfortable. Practice getting out of your wetsuit. Many veteran triathletes leave their bike shoes clipped onto their pedals and secure the heel of one shoe with a rubber band to keep the pedals in place. If you use this technique, you’ll want to practice mounting and dismounting your bike repeatedly until you can do it in your sleep. Make sure your bike is set to the correct gear before you park it. Everything you do in a transition should be as intuitive as possible before race day.


    Cut down on the things you do in each transition area. Use cycling shoes with hook-and-loop straps and no laces. If you use lace-up running shoes, try using elastic laces and leaving them pre-tied. For shorter events, you may consider going sockless for the cycling portion of the race. Some triathletes go sockless for the entire event. Unless you’re already used to running without socks, try it out beforehand to see if your feet can handle it.

    Invest in a Tri-Suit

    A tri suit is the ultimate base layer that you can wear through all three stages of the event. Adding or subtracting other layers during transitions is quick and easy over a skin-tight tri suit.

    Avoid Navigation Nightmares

    Transition areas are chaotic. You may have a hard time distinguishing your bike from the hundreds of others. On race morning, rack your bike and practice coming from the swim exit and the bike entrance. From your rack, study the bike and run exits and the quickest way to get to them. Tip: In a sea of parked bikes, it can be hard to spot your own. Consider tying a brightly colored piece of material to the handlebar or seat post of your bike to help you identify it easier.

    Keep Moving

    Don’t be afraid to do things as you’re still moving. Start removing your wetsuit as soon as you exit the water. After you get your wetsuit, cap and goggles off, you should be able to simply grab your bike and head to the mounting zone.

    Gear Check

    Make a checklist and double check your clothing and equipment twice before an event. It would be a shame to arrive at the race and realize you forgot your swim goggles or timing chip. Go over your bike thoroughly, checking tires, tire pressure, brakes and shifters. If you purchase new shoes, be sure to break them in before the race. If you get a new tri suit, take it for a test ride and run. If you can, take it for a swim and see how it feels wet. Don’t forget the sunscreen.