Anatomy of a Workout: Bike – Fatigue Rate Test

Have you ever wonder how a coach analyzes your workouts? In our new series of articles entitled Anatomy of a Workout, we ask Trismarter coaches to look at the results of an athlete’s workout, and give you some insight into what they think about when analyzing the hard work that goes into completing a training session.

In this installment of Anatomy of a Workout, Coach Lee Gardner shares his analysis of athlete David G.’s Fatigue Rate Test bike workout.

To begin, here is a description of the workout as it was given to the athlete:

Warm up:
20 minutes. On bike trainer. Begin easy and build to zones 2-3 by the end. Include 3x30s spin-ups (30s RI), and 2-3 bursts of of higher intensity lasting up to 1-2 minutes.
Main set:
3×17 minutes @ 3-5 beats below LTHR. Hold race effort cadence (90-100rpm), in aero-position. Use the first 2 minutes to reach intended HR. Recovery interval is 8 minutes (hold 90+rpm) in Zone 1, out of aero-position.
2×7 minutes in Zone 2 with 70-75rpm cadence. 3 minute RI.
Warm down:
5-10 minutes easy spinning.

It’s assumed for this workout that the athlete has both a time trial/triathlon bike, uses a power meter, and performs the workout on a bike trainer, although the workout can also be done on the road.

Before we look at the workout details, let’s put this into some context by briefly profiling the athlete, David G. David is an age-group triathlete who races primarily half-ironman or Ironman 70.3 distance events (although not exclusively). His results at this point have shown improvement. His most recent and best performance at HIM was 4:45 with a bike split of 2:32. He has a strong bike-run combination, however improvements in bike strength and strength endurance will likely help him make the jump from 4:45 to sub-4:30 within the next year.

This particular workout was scheduled for David for two reasons:

  1. To test his power degradation at race pace effort: We do this by having him reach his goal heart rate within two minutes, then hold the effort for 15 minutes. After each interval, he is given an eight minute recovery (but is instructed to hold 90rpm during the recovery).
  2. To improve strength endurance by integrating strength intervals to the back end of the workout: This is accomplished with 2×7 minutes of low cadence and moderately big gearing. These intervals are more taxing to the muscles involved in cycling, and less on the cardiovascular system, so while the interval might seem a little easy at first, it is definitely working the muscles used to push big gears.


Bike workout analysis

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To start the analysis, let’s take a look at the first part of the main set of the workout. After a 20 minute warm up, David completed the first interval having produced an average of 209 watts (w) at a heart rate of 149 beats per minute (bpm). Additionally, his cadence average was 98 rpm. From an effort perspective, this was exactly where he wanted to be, which for HIM race effort is about 10% below his predicted lactic threshold heart rate. If we fast forward to interval #3, we see that both his average power and his average heart rate dropped to 197w and 146bpm respectively. This is degradation of about 6%, which is a good indicator that although he is in decent physical condition, additional work on endurance, strength, and strength endurance are needed in order for him to maintain the type of power output produced in the first interval. Likely, additional intervals would have seen an even greater drop in power output.

Bike workout analysis

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In part two of the main set, David did 2×7 minute intervals using a moderately big gear with a low cadence of 70-75rpm. Because we already knew that David needs to work on building strength endurance, I tagged this short set of intervals at the end of the workout in order to force him to work his leg muscles hard in the back part of the workout. This forces the body to adapt to pushing roughly the same amount of power desired for race effort while keeping the cardiovascular output much lower than race effort. This is indicated in each of the intervals by the combined average of 198w and average heart rate of only 134bpm.

In this workout, David achieved his goal of completing the workout to the best of his ability, and in doing so, shed light on weaknesses that are apparent in the results of the 3×17 degradation intervals. Moving forward, because he is still early into his season of training, David’s bike training program will focus on building endurance, strength, and strength endurance until he begins to exhibit the adaptations needed to complete similar degradation tests without losing more than 5% power output between the first and last interval.

Looking for a triathlon coach to help you make the improvements you want to see in your performances? Trismarter Triathlon Coaching Services might be your answer! Contact us today for a free consultation.