If you’ve decided that this is the year you’ll finally become a triathlete, you’ve probably asked the same question every beginner does: “How long will it take me to train for one? Is 3 months enough?”

There’s no single answer that fits everyone. But there is a simple approach to determining how long it might take—by following a step-by-step process based on where you are right now. Think of it like a flowchart: start with the swim, move to the bike, then to the run. Each step helps you estimate how many weeks you’ll need to be race-ready.

Step 1: Choose Your Target Race – And Hence Your Course Distance

If this is your first triathlon, you’re probably looking at one of two options:

· Sprint distance — 750m swim, 20km bike, 5km run

· Olympic distance — 1500m swim, 40km bike, 10km run

Most beginners start with a sprint because it’s long enough to feel like a challenge but short enough to train for in a few months. The Olympic distance usually takes a few extra weeks of preparation.

Step 2: Start with the Swim

For nearly every new triathlete, swimming is the biggest hurdle. It’s not just about endurance—it’s about technique and comfort in the water.

Ask yourself:

Can you swim at least half the course distance without stopping to rest?

If yes, you’re ready to move on to the land-based parts of training. If no, plan to add 3–4 weeks to your timeline for more focused training in swimming technique and endurance.

Here’s why: swimming longer distances efficiently is mostly a technique issue, not an endurance issue, as is the case with the land-based parts of the race. The fastest path forward is usually to spend a few focused sessions working on body position, breathing rhythm, and stroke efficiency. A few lessons with a coach, ideally with video, can dramatically improve your efficiency and save you a lot of time later on. It’s one of the most efficient uses of your time and money early on in your journey.

Step 3: Test Your Bike Fitness

Next, check where you stand on the bike.

Can you comfortably ride the course distance? Or better yet, 30% further?

That means being able to ride about 26km if you’re training for a 20km sprint bike leg, or roughly 50km if you’re preparing for an Olympic-distance race. This extra cushion helps ensure you’ll have enough endurance to handle race-day effort, as well as stacking on a run after your bike ride.

If you can’t yet hit that mark, determine your current longest ride and how far you are from the goal. For every 15% gap between your current longest ride and the course distance, add about 2 weeks of training.

Example: If you can currently bike 15km and need to reach 20km, that’s about a 33% gap. Bridging that safely will take around 4 weeks.

Step 4: Test Your Run Fitness

Once your bike fitness feels solid, it’s time to look at your run.

Can you run the race distance in one continuous effort?

If yes, you can move to the next stage: the “brick” workout. This is where you ride the full bike course distance, then immediately run half the run course distance. If you can do that without major struggle, your endurance base is strong enough to finish the race.

If no, use the same gap calculation as before: add roughly 2 weeks for every 15% distance gap between your current longest run and the race distance.

Example: if you can run 3.5km and need to reach 5km, that’s roughly a 30% gap, or about 4 additional weeks of buildup.

Step 5: Putting It All Together

Let’s look at an example of how this timeline plays out in real life.

Athlete A is training for a sprint triathlon. They have a very common new triathlete background

· They can bike 20km and run 5km without stopping.

· But they’ve never swum more than about 150m continuously.

Here’s the breakdown:

· 4 weeks to build improve swim technique and efficiency, going from 150m to 750m, as well as getting comfortable in open water

· 4 weeks to build “bike-fatigued” running (riding then running)

· 1 week where life inevitably gets in the way (buffer week), or a pre-planned “rest week”

· Race week usually doesn’t count in a training plan….you’re not actually building any fitness in that week

That’s 10 weeks total, on the slightly aggressive side. Most training plans are built from “blocks” of 4 weeks. So rounding this up brings us to about 12 weeks (three months) of total preparation time.

For an Olympic-distance race, most athletes simply double the weekly volume and add 4–6 more weeks, depending on how strong their endurance base is.

Step 6: The Simple Rule of Thumb

· If you’re already active and can swim, bike, or run recreationally: plan on 10–12 weeks for a sprint, or 14–18 weeks for an Olympic.

· If you’re starting from scratch or not yet comfortable swimming: add an extra month to focus on technique and comfort in the water before jumping into full triathlon training.

Step 7: Keep Perspective

Your first triathlon isn’t about hitting every number perfectly—it’s about learning how the three sports fit together, gaining confidence, and crossing the finish line strong and with a smile.

The magic of triathlon training is that progress builds quickly once you’re consistent. Every swim you complete, every ride you finish, and every run you push through adds another layer of fitness and belief.

So don’t overthink it. Follow the flow: Swim comfortably ? Ride confidently ? Run continuously ? Combine them gradually.

With a simple, structured approach, most beginners can go from “never tried one” to “triathlete” in about three months—and that finish-line feeling will make every week worth it.

Step 8: The Training Plan Itself

You’re now probably thinking: “Okay I need 3 months…now how do I use that time to train?” Another extremely common question, and one that I’ll tackle in my next article. Stay tuned!

 

Benjamin Cohen

 

Benjamin (Ben) Cohen is a veteran of the Ontario triathlon scene. He is the founder and head coach at True Trail Triathlon, an Ottawa-based coaching company providing expert, bespoke, 1:1 triathlon and endurance sports coaching, both in-person and virtual formats.