Time Trial Pacing—The Start

posted Jan 3, 2011, 3:11 AM by Donald Vescio   [ updated Jan 3, 2011, 3:36 AM ]

Introduction

Establishing an appropriate pace is critical for successful time trial performance: ride too hard, and performance will decrease over time (and sometimes decrease very quickly); ride too easy, and the risk is that competitors will finish in front of you.  The focus of this article will be on the most critical component of time trialing, which is the start.

An athlete’s anaerobic threshold is a reliable predictor for aerobic exercise (think: endurance).   In most endurance events, it is important to product a steady effort over an extended period of time.  In order to do this, the athlete wants to work at a high enough intensity to be competitive, while still being able to efficiently remove lactic acid as it is produced, thus preventing its buildup in the bloodstream.  Frequently, the term lactate threshold is used interchangeably with anaerobic threshold. 

While most of today’s emphasis is on power values when monitoring performance, there still is a significant body of research that suggests that perceived exertion still is a valuable and potentially accurate tool that an athlete can use to govern pacing during endurance events.    There are a number of perceived exertion scales available.  Gunnar Borg’s original scale ran from values of 6 (20% effort) to 20 (exhaustion); more intuitive are scales based on a simple ten point spread:

  • 0 - Nothing at all
  • 1 - Very light
  • 2 - Fairly light
  • 3 - Moderate
  • 4 - Somewhat hard
  • 5 - Hard
  • 6
  • 7 - Very hard
  • 8
  • 9
  • 10 - Very, very hard

By carefully monitoring performance values such as heart rate and power, an athlete can quickly normalize their sense of perceived effort with actual field metrics.

There are many studies that document how crossing one’s anaerobic threshold during an endurance event results in an overall decreased ability to generate power for the remaining duration of the event.  From these studies, the message is simple: cross your anaerobic threshold at the start of a race, and you’ll suffer lower overall performance than if you more carefully measured your initial effort.

It can be difficult, however, to monitor your starting effort in a time trial, as a number of confounding factors come into play, such as environmental conditions and the excitement of competition.   Even when racing with a power meter, you still need to understand how the event’s duration should shape one’s power profile for the day.  Like most athletic endeavors, you can improve your time trial starts through carefully structured and reviewed training sessions.

 

Using the Computrainer
One of the more useful features of the Computrainer is the ability to compete against a computer generated opponent who can ride can be programmed to ride at a fixed average wattage.  This feature, in combination with capability to generate 3D mode courses that replicate the gradients of favorite races, enables users to establish a structured environment that accurately demonstrates the impact that different starting efforts will have on overall event performance. 

The protocols actually are relatively straightforward: a course is programmed into the Computrainer’s 3D software and a computer-generated opponent is programmed with the percentage of your anaerobic threshold*  that plan on using to pace for the event.    When you ride this Computrainer course, you should display your current and average power output, along with your current and average heart rate.  Ride this course several times over the span of a few weeks; each time that you ride the course, vary the intensity in which you ride the opening miles of your event, paying close attention to you perceived effort.   

By graphing your power, heart rate, and perceived exertion values after each course completion, you will be able to establish your optimal starting strategy and calibrate your perceived exertion scale, which will enable you to successfully pace yourself at the beginning of your race, even if you do not have access to a power or heart rate meter.

 

*Anaerobic threshold is determined through sport specific testing.

 

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