Triathlon Training: Spring Threshold Bricks Boost Long-Term Ironman Preparation

By Natalie Bojko, CTS Senior Coach

The middle of spring is an interesting time for many Ironman triathletes. Some of your are in your final training blocks leading into your Ironman races, while others are building toward summer and fall Ironman races. We frequently utilize shorter triathlons as a training tool for athletes; they’re fun and also great ways to learn good race-day habits and test out race-day nutrition strategies.

Preparing for spring sprint or Olympic-distance triathlons is good for your overall Ironman goal because the paces for all three disciplines are faster than your Ironman paces, and training for these higher speeds early in the year will help you be stay quick as you gradually build toward Ironman.

A great workout to do in the 2 weeks before your first sprint or Olympic distance race of the season is threshold brick intervals. A lot of bricks will include an interval session or long period of threshold-level intensity in the first part of the brick, followed by an endurance pace or even recovery pace in the second part. Instead, the goal of this workout is to get your body used to riding and running at lactate threshold back-to-back and practice your transition skills.

How to do it:

Find a loop course or out and back road that will take you about 10-15 minutes to complete at a fast pace on the bike. Set up a transition area with your running gear and some nutrition and hydration for the workout. You’re going to be completing the bike-run transition 3 or more times during this workout. If you can’t find a road like that, a trainer outside in the driveway or in a park will also work fine. If all else fails and you don’t feel like you could set up a transition area without your equipment being stolen before you return, consider using the backseat or cargo area of your vehicle as your transition area. It’s not perfect and not entirely race-specific, but it’s better than donating a pair of running shoes or a time trial bike to local thieves.

Warm up on the bike for 15-30 minutes at a level of about 6 out of 10 intensity (just easier than Ironman race pace). Complete the first loop of your course or a 10 minute interval on the bike at lactate threshold power or an 8 out of 10 intensity level. Immediately at the end of the interval, transition to your running gear, at race speed if possible. The goal is to get off your bike and into your run gear in less than 1 minute.

The run portion of the brick should be 5 minutes at threshold pace (10k race pace) or an 8 out of 10 intensity level. After the run portion, cool down by grabbing a water bottle and walking easy for 2-3 minutes. The total recovery time between intervals should be about 7-8 minutes so you can either spend the rest of the time spinning easy on the bike or continue to walk and take in some nutrition. You’re not going to need a lot of calories to get through this workout, and you need to be somewhat careful not to overload on either calories or fluids during the recovery periods because too much food/fluid in the gut can lead to stomach upset as you transition from the ride to the run.

The goal is to accumulate 1 hour of time at threshold intensity, so if your bike intervals are 10 minutes and the run is 5 that would be 4 intervals. If your bike loop takes closer to 15 minutes and the run is 5 then you should do 3 intervals. After the last interval, get back on the bike and spin easy for 20-30 minutes.

Since you still have 2 weeks before the race, spend some time evaluating if you need to do more work on your transition skills or adjust your nutrition strategy due to the higher intensity of the race. Being optimally prepared in advance of the race means you will have less anxiety on race day and ultimately will be able to race faster and have more fun!

Natalie Bojko is a Senior Coach for Carmichael Training Systems. In 2011 all 20 of her Ironman triathletes achieved their goals and completed their Ironman races, including three Kona finishes!