Running

Running in a triathlon isn't quite the same sport as running on its own.

Even elite athletes run slower off the bike than they would when running fresh. The goal isn't to eliminate that difference completely. It's to train specifically for it, so you're prepared for what your legs will actually feel like when you reach the run.

The better you understand that difference, the less likely you are to mistake normal race fatigue for a problem.

Building Endurance the Sustainable Way

Because you're also swimming and cycling, your running volume needs to work alongside the other two disciplines — not compete with them.

• 2–3 runs a week is typical for beginners. That's enough running to build useful endurance while leaving room for swim and bike sessions. If you're used to running more frequently on its own, you'll probably need to trade some running volume for the other two disciplines.
• Keep most runs easy. Roughly 80% of your running should be at an easy, conversational effort, with the remaining sessions providing harder or more race-specific work. Running slower can feel counterintuitive when you're trying to improve, but easy mileage builds the aerobic foundation you need while making recovery easier.
• Increase gradually. A common guideline is to increase running volume by no more than around 10% from one week to the next. It's not a magic number, but it encourages the gradual progression that helps reduce unnecessary overload.

The biggest mistake is trying to improve running by making every run harder.

You don't need every session to prove you're getting fitter. Sometimes the most productive run is the one that leaves you feeling like you could have done more.

Improving Efficiency

Small technical habits can make a surprisingly large difference, particularly once fatigue starts affecting your form.

• Strides. Short, fast bursts of around 10–20 seconds with plenty of recovery can help develop smoother running mechanics and leg turnover without turning the session into a hard workout.
• Hill repeats. Running uphill develops strength and resilience that can help you maintain better form when your legs become tired. That benefit still matters on relatively flat race courses.
• Easy runs aren't wasted runs. They provide much of the aerobic development that supports your harder sessions. Resist the temptation to turn every easy day into a race.

Running efficiently isn't about forcing perfect technique. It's about developing a relaxed, repeatable movement pattern that still works when you're tired.

Running Off the Bike — The Skill Almost Nobody Arrives Prepared For

Here's the part that catches almost every first-timer by surprise: you will never start the run in a triathlon with fresh legs.

Coming off the bike, it's extremely common to experience a heavy, almost "jelly-legged" sensation during the first few minutes. You've been sitting in a cycling position, your legs have been working in a very different movement pattern, and you're suddenly asking them to run.

It can feel strange.

It doesn't necessarily mean anything is wrong.

For many athletes, that sensation settles after the opening minutes as they find their running rhythm. The important thing is not to panic and immediately respond by trying to run harder.

The best way to become comfortable with the sensation is to practise it before race day.

That's where the brick session comes in: running immediately after cycling so your body learns what that transition feels like. You don't need huge amounts of brick training. Even occasional, well-planned bike-to-run sessions can make the transition feel far less unfamiliar when it happens for real.

Pacing the Run

The most common beginner mistake on the run is almost the mirror image of the bike mistake: starting too fast.

After swimming and cycling, finally getting upright and running can feel like a huge release. Add race-day adrenaline and it's very easy to convince yourself that you have more speed available than you actually do.

The result is predictable: a strong opening section followed by a much harder final stretch than necessary.

Instead, make the beginning deliberately controlled.

• Let your legs settle. The first few minutes don't need to be fast.
• Find a sustainable rhythm. Aim for an effort you can maintain rather than chasing the pace of runners around you.
• Build into the race. If you're feeling good later in the run, you have earned the opportunity to increase your effort.

A conservative start can feel almost too easy.

That's often exactly the point.

The best run isn't necessarily the fastest first kilometre. It's the one where you still have something left when everyone else is starting to slow down.