Tuesday, January 20, 2015

Using Power-Based Metrics in an Annual Training Plan

Since the advent of periodization over fifty years ago, coaches have sought to quantify the amount of training their athletes perform as part of developing training plans that ensure peak performance at key events. Traditionally, training load has been measured two ways—total distance and/or total hours ridden. While these measures provide some indication of training load, they lack the specificity required to assist the athlete in achieving peak fitness and minimizing the risks of over-training.

Using training zones in workouts adds some specificity to simple measures of time or distance. However, training zones indicate only the quality of the training performed and are too broad to provide an accurate indication of overall training load. For example, consider the difference in intensity between riding one hour at 60% of threshold power versus one hour at 70%. Both would fall within the endurance training zone, yet clearly the second ride is going to produce more training stimulus, possibly as much as 36% more, a significant difference when trying to plan a steady, safe progression in fitness.

Adding Power-Based Metrics

With the introduction of power meters, coaches had a new metric at their disposal: the kilojoule, a measure of the actual work performed by the athlete. The kilojoule provides a more specific measure of training volume than do total hours or distance. If we take the same two rides mentioned above but set a goal in terms of kilojoules achieved rather than time or distance, the ride at 60% would simply be extended to 70 minutes in order to equal the amount of work performed in the one-hour ride at 70%.

The use of kilojoules works very well for rides at lower levels of intensity, but because the power-work relationship is linear, it still fails to adequately represent the true training stimulus produced by harder efforts, such as intervals. The muscular fatigue and recovery requirements following an hour workout in which an athlete does six five-minute efforts at VO2Max are much higher than riding one hour steadily at 75% of threshold power, yet the two rides require the same number of kilojoules of work.

A New Method for New Data

With the development of more capable cycle computers and robust analysis software, coaches and athletes now have numerous power-based metrics at their disposal to quantify training stimulus and fitness much more accurately. It is now possible for coaches to design and implement an annual training plan that utilizes these power-based metrics instead of the more traditional miles or hours ridden. Most software programs designed to analyze power data provide the three metrics needed to design an annual plan:
  1. The relative intensity of the workout (adjusted by an algorithm to account for the higher impact of super-threshold efforts)
  2. The training stimulus for the workout (a number of points based on relative intensity and workout duration)
  3. The athlete's current level of fitness (a number of points based on the cumulative effects of several weeks of workouts)
A plan that uses power-based metrics still uses many of the core principles found in more traditional training plans. The macrocycle will be composed of several mesocycles designed first to develop the athlete's aerobic fitness and then to work on more specific energy systems in preparation for the racing peak (I’ll discuss some variations to this more traditional approach later in the article). Maintaining a familiar overall structure to the annual plan makes it easier for an athlete to adapt to a new way of thinking about training and provides the coach with a familiar methodology from which to adjust to this different approach.

After determining the athlete's current level of fitness (either through the analysis of past workout files or through an approximation of average daily training load), the coach plans the athlete's progression by entering future values for weekly training stimulus, taking into consideration recovery, planned breaks from training, and other events that may affect training. For example, if an athlete currently has 60 fitness “points” and the goal is to build that up to 100 in eight weeks, the coach plans a weekly training load that allows the athlete to reach this score of 100 at an average of 5 points per week. These weekly training load goals, in combination with a graphical representation of their impact on athlete fitness (as in the chart below), can be a useful means to help an athlete visualize the annual plan and how it will prepare them for goal events.

A graphical representation of athlete fitness can help athletes see the big picture.

Next, the coach plans each microcycle, ensuring that the workouts meet the specific training needs of the athlete and also elicit the weekly training stimulus desired based on the annual plan. Factors such as available hours to train and the athlete's daily schedule are considered during this step. As the athlete completes the microcycles, actual values for weekly training stimuli are entered, and fitness progression is adjusted up or down based on the actual training load.

Providing Data-Driven Feedback to the Athlete

In addition to the fitness progression graph shown above, creating graphs that compare actual versus planned progress can be an excellent way to present the athlete a quick picture of his weekly performance in relation to his goals and evidence of his overall fitness progression. They also motivate the athlete beyond just completing each individual workout by providing both medium and long-term feedback about the athlete's progress.

Graphs representing actual (dashed red line) vs. planned (solid blue line)
weekly stimulus (left) and overall fitness (right)

The coach makes modifications to the weekly goals as needed to suit the athlete's situation. This will occur frequently when first developing the plan, as both the coach and athlete will still be learning how much training stimulus the athlete can perform each week and how the athlete handles the overall training load across each mesocycle. With time, however, both coach and athlete will be able to tailor the workload and recovery periods to suit the athlete's needs and abilities. Since the plan is power-based, increases in the athlete's threshold power are automatically factored in to the calculations of training stimulus, as long as the coach and athlete make the appropriate changes in the program they’re using.

Special Considerations and Potential Pitfalls

Naturally, each athlete is an individual, and this approach to developing an annual plan requires attention to that fact. Since power-based metrics are derived from both intensity and duration, an athlete can derive the same number of stimulus “points” riding long duration at low intensity as they would doing intervals at aerobic capacity for a short duration, yet the physiological benefits they would receive are quite different. Therefore, the coach must ensure that the prescribed training focuses on targeting the energy systems specific to the athlete's stage of development and the demands of his goal events, not merely the achievement of some arbitrary number of training stimulus points.

In addition, special attention must be paid to the overall fitness ramp rate: the rate at which an athlete increases his fitness level each week. Depending upon the software one uses, there is typically a range of points that is considered an acceptable rate of weekly increase, beyond which the athlete runs greater risk of over-training. Additional factors such as athlete age, prior injuries, and overall resilience can affect the range of points that will be most productive. Utilizing a graphical representation of an athlete's weekly ramp rate can be a very effective means of ensuring that the athlete is able to steadily progress.

Charting the fitness “ramp rate.” The colored lines indicate the range of rates appropriate for the athlete.

As with all annual plans, unforeseen disruptions will prevent the athlete from completing both prescribed workouts within a microcycle or even entire microcycles within a mesocycle. When this occurs, traditionally the athlete either writes the missed work off entirely or attempts to make up the missed work by suddenly increasing training volume. With a power-metric training plan, the coach and athlete can collaborate to determine how much, if any, additional training load can be applied across several weeks while still keeping the athlete's ramp rate within the appropriate range. This collaboration is most productive when combined with a graphical representation of how the lost training stimulus and the resulting alterations to the upcoming weeks will get the athlete back on track, since it allows the athlete to see how short-term setbacks in training self-correct over time.

The charting of athlete fitness helps the athlete see the impact of missed training (sudden dip in dashed line)
and adapt the training plan to regain lost fitness without risking over-training.

Variations to the Plan

Using power-based metrics presents several opportunities for modification of the annual plan to suit the needs of the athlete. A few possible variations include:
  • Athletes engaged in a weight-loss phase during the post- or pre-season can include the number of kilojoules burned along with the training stimulus metrics to ensure that they consume enough calories to lose weight without losing power.
  • Athletes desiring to maintain a higher level of fitness during the post-season can adjust their weekly training to minimize or eliminate the drop in fitness that normally occurs during the transition period.
  • Athletes can tailor the frequency of rest weeks to suit their physical and mental fortitude. Some athletes may be able to handle a decrease in the frequency of rest weeks during the base cycle, and a few may even have the resilience to eliminate rest weeks entirely. Other athletes may determine that more frequent rest helps prevent bigger setbacks such as illness and injury.
The use of power-based metrics to develop annual training plans still requires the same level of attention to detail and to the “art” of coaching that is required of any other training plan method, and the metrics used are certainly not flawless indicators of an athlete's fitness or perfect predictors of an athlete's performance in races. However, they do provide a more effective means of gauging athlete development and managing an athlete's preparation for key events than more traditional methods such as total time and total distance. As power meters become more ubiquitous, not only among professional and amateur racers but also among serious recreational riders, using power-based metrics has become a viable and effective method of training plan development and deserves a place in every coach's repertoire.

Want to learn more about annual training plans and how to make yours the best for you? Click here to contact us, ask questions, or inquire about coaching assistance. 

Coach Jordan Whiley Peaks Coaching Group
Jordan Whiley has been a competitive cyclist and educator for more than fifteen years and has been training and racing with power meters since 2005. He is an elite coach with Peaks Coaching Group, and he also teaches high school mathematics and science. Jordan can be contacted directly at info@peakscoachinggroup.com or through PeaksCoachingGroup.com

Photo: PCG athlete Lefteris Bokas wins the Parnis Race.