The Secret to Getting Faster is Interval Training

Most triathletes spend a lot of time training steadily. And that’s a good thing — steady, aerobic training builds the foundation that all endurance performance sits on.

But if you want to actually get faster, not just fitter, you need to include interval training.

Intervals are not about suffering for the sake of it. Done properly, they are a precise tool that teaches your body to move faster, produce more power, and tolerate higher intensities more efficiently.

The problem? Many athletes either:

• Avoid intervals completely, or

• Do them too often, too hard, and without structure

Both approaches limit progress.

Let’s break down how interval training really works — and how to use it well.

What Are Intervals (Really)?

Interval training simply means alternating periods of higher intensity work with recovery.

Instead of training at one steady pace, you:

• Push slightly (or significantly) above your normal sustainable effort

• Recover just enough to repeat that effort again

That combination is what creates adaptation.

The purpose of intervals is not exhaustion.

The purpose is exposure to a specific intensity that steady training can’t reach.

Why Intervals Make You Faster

Intervals work because they stress key physiological systems that steady training doesn’t fully challenge:

1. They Raise Your Thresholds

Intervals near threshold or VO₂max help raise the pace or power you can sustain before fatigue sets in.

In simple terms:

You can go faster before it starts to hurt.

2. They Improve Efficiency at Speed

Intervals teach your body to move efficiently at faster paces — whether that’s:

• A stronger bike position

• A quicker run cadence

• Better breathing control

This is especially important for race pace performance.

3. They Create Stronger Adaptation Signals

Short, focused intensity sends a clearer signal to your body to adapt than endless moderate training.

That’s why one well-executed interval session can be more effective than two mediocre ones.

The Most Common Interval Mistakes

Before we talk about how to do intervals well, it’s worth addressing what often goes wrong.

❌ Doing Them Too Often

More intervals does not equal faster progress. Most triathletes do too much intensity, not too little.

For most athletes:

• 1–2 interval sessions per discipline per week is enough

• More than that often reduces consistency and recovery

❌ Going Too Hard

Intervals are not max efforts unless they are designed to be.

If every interval feels like a race:

• Recovery suffers

• Technique breaks down

• Progress stalls

Good intervals should feel controlled but challenging, not desperate.

❌ No Clear Purpose

“Hard session” is not a purpose.

Every interval session should answer one question:

What am I trying to improve today?

Speed? Threshold? Race specificity? Fatigue resistance?

If you can’t answer that, the session probably isn’t well designed.

How to Structure Intervals Properly

Here’s a simple framework that works across swim, bike, and run.

1. Choose the Right Intensity

Intervals usually fall into one of these categories:

• Threshold intervals

Hard but sustainable efforts (e.g. 5–15 minutes)

Goal: raise sustainable race pace

• VO₂max / high-intensity intervals

Shorter, harder efforts (e.g. 30 seconds to 3 minutes)

Goal: improve speed and aerobic capacity

• Race-pace intervals

Controlled efforts at target race intensity

Goal: efficiency and confidence

You don’t need all of these at once. Pick what fits your current phase.

2. Match Work and Recovery

Recovery matters just as much as the effort.

General guideline:

• Shorter, harder intervals → longer recovery

• Longer intervals → shorter recovery

Recovery should allow you to:

• Maintain good technique

• Repeat the effort at similar quality

If every rep gets slower, the session is too aggressive.

3. Keep the Total Load Reasonable

More is not better.

A good interval session:

• Has just enough quality reps

• Leaves you tired, not destroyed

• Allows you to train well the next day

Consistency across weeks beats a single heroic workout.

How Often Should You Do Intervals?

For most age-group triathletes:

• Base phase:

Light intervals or short controlled efforts, once per week

• Build phase:

1–2 focused interval sessions per discipline per week

• Race-specific phase:

Intervals become more race-paced and purposeful

Intervals should support your training, not dominate it.

The Big Picture

Interval training is powerful — but only when it’s used intelligently.

The athletes who get faster long-term aren’t the ones who smash themselves every session. They are the ones who:

• Respect recovery

• Choose the right intensity

• Apply intervals with purpose

• Stay consistent month after month

That’s smart training.

And smart training wins.

Smarter training. Better decisions.

— TriWise