How To Train For a Triathlon: A Guide For Runners

Taking the step from running to triathlon isn’t a continuation of the linear progression of a runner, but a widening of your training scope – it means adding new disciplines and incorporating several different training modalities at the same time.

In this article, UESCA-certified Triathlon coach Sam Farnsworth walks us through how you can go from being a runner to a triathlete.

Want to try something new?

Raise the bar on your personal challenges?! 

A triathlon is a great idea! 

Three sports wrapped in one, triathlon is a total body workout during training and racing. 

Triathlon is also an exponential step up in race strategyplaying to your strengths, mitigating your weaknesses, all the while fueling and budgeting your energy level.  

Before we dive deep into the various training, gear, and strategy considerations, let’s lay out the options for a triathlon. 


Triathlon Distances

There are four standard triathlon distances:



Half IRONMAN (or IRONMAN 70.3),

and IRONMAN.  

The distances that follow are rules of thumb, but some venues will tinker with the actual distances given the available ponds, lakes or roads available.

Sprint Triathlon

Swim: 400M (0.25Mi), Bike 10K (6.2Mi), Run 5K (3.1Mi).

Sprint distances are highly variable.  That said, this distance can be completed by a mid-packer in about 1 hour.

Olympic Triathlon

Swim: 1500M (0.9Mi), Bike 40K (25Mi), Run 10K (6.2Mi). 

And this distance might take a first-timer 2 ½ – 3 hours to complete.

Half Ironman

Swim: 1900M (1.2Mi), Bike 90K (56Mi), Run 21K (13.1Mi). 

Plan on 6 hours for a first-time crack at this distance, although that depends a lot on the course – hillier = longer.


Swim: 3800M (2.4Mi), Bike 180K (112Mi), Run 42K (26.2Mi).  

I recommend you pause here and focus on one of the three distances above for the first couple races. 

An Ironman for a strong mid-pack racer will take about 11-12 hours. 

That’s a BIG leap from a 4-hour marathon and requires a significant increase in weekly training hours. 

Plus, an Ironman requires a lot of planning, equipment, nutrition strategy and a significant entry fee (> $750). 

Pro Tip – Try a sprint at your earliest convenience, get a taste for the 3 sports within the sport and see how you navigate the transitions.  And you can always finish with a flat out 5K…  done in less than an hour.


Triathlon Training

There are many generic training plans that will get you through your first race, or even your first year of races. 

That said, I will throw in a couple of guidelines:

  • Swim at least 2-3 times a week for 45-60 minutes.
  • At a minimum, your bike training should reflect the percentage of time you will be on the bike in a race

    Say you plan to complete an Olympic triathlon in the following estimated times: swim – 30 minutes, bike – 75 minutes and run – 50 minutes, for a total of 155 minutes.
  • Biking is almost half of your total race time.  Plan to spend at least half of your budgeted training time on the bike. 

    This investment is needed to both get your muscles used to riding, but as important, strong bike legs will transfer to a stronger run.
  • Reduce your run training to accommodate your larger training schedule but try to still run 3-4 times/week to maintain durability, even if you have to shorten runs.

Here’s a little bit deeper dive on training.


Triathlon Training: Swimming Tips

Get going ASAP. 

Particularly if you are not a great swimmer. 

The advantage good swimmers have over the rest of us is hours in the pool.  Consider swimming with a group for motivation and a little push on pace. 

Swim with a cap on – this will be required in your race. 

Practice raising your head during swimming to site the end of the pool, or a spot on the lake. 

And if your event has an open water swim, definitely get some open water practice before hand – it’s totally different than swimming in a pool.

Many (most?) triathletes use a wetsuit.  The primary advantage is the buoyancy it provides, allowing the user to stay flat at the surface.  A wetsuit is not allowed if water temperature if 84F (29C) or higher.  These are optional, but if you have access to one, you should be practicing in the suit at least once/week in the last 4-6 weeks before the race – watch for chafing at the armpits and back of the neck.

Pro Tip – Joining a Masters group is probably your biggest bang for the swim training buck.  


Triathlon Training: Bike Tips

Bike – Assuming you have a road, gravel, cross bike – use the bike you have for your first triathlon.  But do make sure you have had a GOOD bike fit.  In your new pursuit – most of your training time will be spent on your ride!

Should you cycle with an aero bar?

I would suggest that for your first 1-2 triathlons, maybe not.  Here’s why:

1) make sure you like your new sport before you throw too much new $ at it;

2) aero bars on a non-tri bike can stretch out your back, especially if you have more of a touring bike with a long top tube. It may be less of an issue with race bike, but it definitely will change your center of gravity;

3) if you get aero bars, plan to spend at least 50% of your time using them for 45-60 days before your race, so your body will get used to them and in particular, you are practicing transitions to the bike to practice opening up your hip flexors.

Pro Tip Triathlon aero clothing and/or skin suits are worth having.  Saves you clothing changes, maximizes comfort between the bike and run, and they have pockets to carry nutrition. 

Practice the bike in tri shorts – if you only wear bike shorts during training, you are in for a rude awakening come race day.

How To Train For a Triathlon: A Guide For Runners 1

Triathlon Training: Running Tips

Running – You’re going to run a bit slower in a triathlon. 

You’re running on tired legs, so pace yourself accordingly.  Do a “brick” workout at least once every two weeks, where you transition from your long bike ride to run 1-3 miles. 

It takes 10 minutes or so to “sort out” your muscles and adjust to running, and (for me) to get my low back relaxed and hips open after several hours on the bike.

Nutrition – What, when and how to eat.  You’ve no doubt spent time in this realm if you are running marathons. 

Things to consider:

  • What are you eating before the swim?
  • Do you know how to eat on the bike?
  • What should I be drinking throughout the race?
  • How full do I want to be when I start running?
  • And of course, what do I want to eat on the run?

You know from marathoning, that nutrition can make or break your race. 

Triathlon is no different in that respect.  It IS different because you are fueling for different disciplines and potentially a longer race duration.

The answer?  Same as marathoning.  Organize and practice your fueling during training.   Do it at the pool/lake before you swim, on the bike and on the run.  Aim for 150-250 total cal/hour total (ideally more cal/hour the longer you are going).  And make sure you have a source of electrolytes.

Pro Tip – Research the nutrition available at your target race.  Consider structuring your nutrition for that race around what is available – if it works for you.  I often opted for the electrolyte drink available during the race but carried my own gels.


Race Day Advice

Race day is here!  How about getting up at 4 AM to eat applesauce, banana, and protein shake 3 hours before the start of the race…  is that different from your marathon race day? 

Maybe not.    Just like marathoning, once you get some breakfast in, all you have to do is manage the nerves and get to start line.  Once the gun goes off, just enjoy!

And remember, don’t try anything new on race day.

Transition Area Preparation

After you check-in, get the lay of the land.  Where’s the transition area?  How about the exits from swim and bike?  Entrances to bike and run?  

Be prepared to organize all of your equipment in the space between two bikes (or roughly 0.5M x 1.5 M).  Make sure your bike equipment is easiest to reach.  This area will be chaos by the time you transition to the run…


The Swim

It is super common to have some anxiety about the swim. 

Especially if you are not a strong swimmer.   My favorite tactic? 

Wait 20 seconds to get in the water and avoid some of the chaos. 

It helps keep the HR down, less frantic and it really doesn’t impact your overall time.

If you elect to jump in with everyone else, expect some bumps, pushes, random hands, and feet – especially at the beginning and when turning at buoys.  Try to follow someone going your pace and poke your head up once in a while to sight the next buoy. 

When you exit, only stand up when your hands touch the bottom (it’s hard to walk through deep water!).

Unzip your wetsuit as you are exiting the water and start peeling the sleeves off.  Maybe grab a quiet spot on the way into transition (instead of in transition) to sit and take off the bottom of your wetsuit.


The Bike

Your bike helmet must be clipped on before you can mount the bike.

Remember that you will be soaking wet when you get out on the bike, which for me means a little cold.  Throw arm warmers on if it’s a cool day, otherwise wait for the first hill and you will warm right up. 

Settle in and get comfortable, lock in your “all-day” pace.  The bike should be a 6 out of 10 effort, HR the same whether going up a hill or on a flat.  

Use the easier pace to get some calories in, especially on the first half of the bike.  Plenty of liquids as well. 

Remember – NO Drafting in all but ITU races.  If you go to pass someone, do so assertively.  When you get back to transition, be careful dismounting and running in bike cleats.

The Run

Settle in for the first third and get your legs going.  After that, you know how to run! 

Just keep fueling.  My favorite go-to is the 50-60 calorie chews, one every two miles.

Pro Tip – One strategy to “hold yourself back” is to take 45 sec and walk through aid stations, get your nutrition down, then start running again.  


Race Day Checklist

Run through this checklist when preparing all your gear for race day:

  • Tri top/shorts,
  • Wetsuit (if using),
  • Swim cap,
  • Swim goggles,
  • Glide for chafing,
  • Towel for transition area,
  • Race number on race belt (if using),
  • Bike,
  • Bike water bottles,
  • Bike shoes (if using),
  • Socks (if using),
  • Helmet,
  • Sunglasses,
  • Running shoes,
  • Nutrition.

Pro Tip – If you don’t have one for running, consider a race belt with pockets for nutrition and tabs for race number.  It’s a small item but makes transition faster and you can use this in any running event as well.

Thomas Watson

Thomas Watson

Thomas Watson is an ultra-runner, UESCA-certified running coach, and the founder of His work has been featured in Runner's World,, MapMyRun, and many other running publications. He likes running interesting races and good beer. More at his bio.

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