Interval Workouts for Triathlon Training

How would you like to improve your race performance by three percent in four weeks? Three percent isn’t much, you say? Well, that would mean going from a 2:30 Olympic-distance finish time to a 2:25. For an Ironman three percent off of a 12-hour time would put you at the finish line 21 minutes sooner. Intervals are the key to such gains — if you do the workouts correctly.

How would you like to improve your race performance by three percent in four weeks? Three percent isn’t much, you say? Well, that would mean going from a 2:30 Olympic-distance finish time to a 2:25. For an Ironman three percent off of a 12-hour time would put you at the finish line 21 minutes sooner. Intervals are the key to such gains — if you do the workouts correctly.

And three percent is conservative based on research that has looked at the benefits of interval training. Some studies put the performance benefits as high as six percent, so you might be able to double those time gains described above. Most studies found the benefits occurred with only one interval session per week. That’s four workouts in a month to become at least three-percent faster. Most triathletes would improve their race times significantly by doing one interval workout in each sport weekly during the build period of their seasons. The build period starts about 12 weeks before your first A-priority race of the season and ends two or three weeks before.

But I Already Do Intervals 

Most triathletes tell me they do intervals. I’ve found few self-coached athletes, however, who know what the various types of intervals are, how to choose the right one for their needs and how to blend them into a comprehensive training program.

Unfortunately, most triathletes do a workout I call “intervals ‘til you puke.” These are intervals done as fast as possible with no thought as to what the pace or power should be, how long the fast portions should be, or how much recovery should be taken between the fast portions.

Then there are athletes who don’t do intervals at all. They dislike the agony and are more likely to swim, bike and run at moderately hard efforts a lot. This is 3-zone training and has little benefit once you leave the base period of your season—unless you are training for half ironman- or ironman-distance races that are raced at moderate effort. But for the shorter distances 3-zone workouts are not hard enough to produce the physiological benefits necessary to race faster, but are hard enough to leave you feeling tired and in need of some down time to recover. The worst of both worlds.

What Are Intervals?

So what are intervals all about? Let’s get the language of intervals straightened out first. The word “interval” actually refers to the rest time between the hard portions. But since nearly everyone uses the word “interval” to mean the hard portions it probably would help to eliminate confusion if we call those hard portions the “work intervals” and the easy portions the “recovery intervals.”

The three most critical components of an interval workout are:

  • Intensities of the work and recovery intervals
  • Durations of the work and recovery intervals and the total time spent
  • Work interval intensity within the workout

By changing each of these parts the benefits of the workout are changed. The most common mistakes made by self-coached athletes are to make the work intensity too great and the recovery interval too long.

What Kind of Intervals Should I Do?

How you manipulate these three portions of the workout is based on the distance you race. The accompanying table offers one example of a simple interval workout for each sport for the common triathlon race distances. There are many other ways of organizing these workouts. These are just common examples. Each of these interval sessions may be done once a week for each sport during the build period of your season.

Interval Components Based on Race Distance and Sport

Race Distance – SportWork Interval Duration*Recovery Interval Duration*Work Interval Intensity**Recovery Interval Intensity# of Work Intervals (reps)***Example WI (RI) 

****

Sprint – Swim100 y/m10-20 secT-5Stand at wall4-75×100 @ T-5 (15 sec)
Sprint – Bike3 min3 minCP6 

or

RPE9

RPE1 

or

Easy spin

3-65×3 min @ CP6 (3 min)
Sprint – Run3 min3 minCP6 

or

RPE9

RPE1 

or

Easy jog/walk

2-54×3 min @ CP6 (3 min)
Olympic – Swim200y/m10-20 secT+5Stand at wall4-75×200 @ T+5 (15 sec)
Olympic – Bike8 min2 minHR4-5a or 

CP30

or

RPE7-8

HR1 

or

RPE1

or

Easy spin

3-64×8 min RPE7-8 (2 min)
Olympic – Run6 min90 secHR4-5a or 

CP30

or

RPE7-8

HR1 

or

RPE1

or

Easy jog

3-64×6 min RPE7-8 (90 sec)
Half-Iron – Swim300 y/mEasy 25 swimT+10Easy 25 swim4-75×300 @ T+10 sec (25 easy)
Half Iron – Bike20 min5 minHigh HR3 or 

CP90

or

RPE5-6

HR1 

or

RPE1

or

Easy spin

2-53×20 min @ CP90 (5 min)
Half Iron – Run12 min3 minHigh HR3 or 

CP90

or

RPE5-6

HR1 

or

RPE1

or

Easy jog

3-63×12 min @ CP90 (3 min)
Ironman – Swim500 y/mEasy 25 swimT+15Easy 25 swim4-75×500 @ T+15 sec (25 easy)
Ironman – Bike30 min8 minLow HR3 or 

CP90

or

RPE 5-6

HR1 

or

RPE1

or

Easy spin

2-53×30 min @ HR3 (8 min spin)
Ironman – Run20 min5 minLow HR3 or 

CP90

or

RPE5-6

HR1 

or

RPE1

or

Easy jog

2-53×20 min HR3 (5 min jog)

* y/m = yards or meters. ”min” = minutes. “sec” = seconds.

** Heart rate (HR) zones based on the system in The Triathlete’s Training Bible. Note that HR is not a good way to gauge intensity of short intervals. T-5 refers to your swim T-time (average-100 pace for 1000-time trial) minus 5 seconds per 100. T+5 is T-time plus 5 seconds. CP means “critical power” (bike) or “critical pace” (run) – the highest average power or pace you can sustain for 6 minutes (CP6), 30 minutes (CP30), or 90 minutes (CP90). RPE is “rating of perceived exertion” and is gauged on a 1- (easiest) to-10 (hardest) scale.

***Start at the lowest number and increase by one work interval weekly over 4-5 weeks. Then maintain the highest level for an additional 3-4 weeks.

****Venues for these workouts are pool for swimming, road or indoor trainer for cycling, track or other soft surface for running. For variety add uphill work intervals or rolling courses for bike and run.

Ultimate Ironman Training Guide
Training Guide

Ultimate Ironman Training Guide

This guide is designed to be used as you train for an IRONMAN triathlon, with in-depth information on every part of the process. Each chapter is packed with tips, workouts, and insights from triathlon coaches, to give you all the tools you need to succeed.