The Basis of Xert™ is MPA™ – Maximal Power Available

What is Maximal Power Available?

Maximal Power AvailableAlso referred to as MPA™, Maximum Power Available or Max Power Available, it is a measure of the maximal power... (MPA™) is a measurement of the maximal power that can be produced by an athlete for a given exercise, factoring in fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power.... Simply, MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More establishes at every given instant, how much power you have.  It is a concept that is well understood by sport scientists and coaches as it establishes the upper limits for activities like running, swimming, cycling, rowing, etc. In the simplest of terms, it is the limit of athletic performance for a given activity, at a given time. MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More forms the foundation of performance and training, albeit indirectly at the moment since as of today, there have been no convenient ways to measure it. Interval training, for example, can be thought of as exercise that reduces and recovers MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More over a series of repetitions.  Coaches will prescribe high-intensity interval workouts with specific intensity, durations and recovery periods to use as part of a training plan.  Knowing what workouts are suitable for the athlete that will enable them to achieve their training goals has been considered part of the art of coaching as it requires experience and a deep understanding of the athlete in order to do well. By determining MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More during bouts of exercise where fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power... has been accumulated, a new way of viewing performance and training is introduced. It provides coaches and athletes with direct feedback on the how close the athlete is to their limit.  This provides numerous benefits as will be explored here.

Review of Power-Duration

In our last blog , we explored the relationship of power-duration and how one’s fitness signatureIt is represented by three values: Threshold Power (TP),  High Intensity Energy (HIE) and Peak Power (PP). The three fitness values are used... is represented by a power-duration curve. Each point on the curve represents a point-of-failure, i.e. an inability to output the target power by the athlete due to fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power.... At precisely the point-of-failure, the target power becomes the athlete’s MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More and any power output beyond this duration is below MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More, by definition of the power-duration curve. In order to return to being able to output the target power, the athlete requires recovery. During a steady-state, fixed power effort above threshold, from fresh to failure, an athlete starts with an MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More that is peak powerAs one of the three parameters that define an athlete's Fitness Signature, this is an athlete's highest possible power.  Sometimes... and MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More reduces to eventually become equal to the fixed power value.  MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More represents their limit at any given moment and at the point of failure, their power equals their limit.  Thus a point of failure can also be viewed as a point of maximal effortSynonymous with point-of-failure, this refers to moments during an activity where an athlete attempts to produce as much power as.... The duration at a given point in time to the point of failure, is often called time-to-exhaustion (TTESee Time to Exhaustion....) and it represents the time it will take the athlete to reach failure. (Note that the use of the word exhaustion may cause confusion with efforts of short duration since failure will be achieved before the feeling of exhaustion.  Exhaustion in this context means failure to produce the target wattage). Steady-State to Failure The affect on MPA is a function of the total amount of energy consumed.  (It is also a function of cadence and this will be explored in a future blog.  For the moment, we’ll assume that cadence is optimal during the effort).  As the athlete fatigues, MPA reduces.  As the athlete rests, MPA rises.  At any point in time, MPA can be determined.  Plotting MPA and power vs. time, we can compare power output with MPA to see how the athlete is performing relative to their MPA: MPA We can now visualize the affect on MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More due to accumulated fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power... and recovery.  We can also compare power output with MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More at a given moment.  When MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More equals the athlete’s power output, we have a point of maximal effortSynonymous with point-of-failure, this refers to moments during an activity where an athlete attempts to produce as much power as... / point-of-failure, by definition.  Also similarly, if the power output crosses the MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More line, the athlete’s signature used to derive the MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More is too low and the athlete has achieved a fitness breakthroughA fitness breakthrough is achieved when your power reaches or surpasses MPA for longer than 5 seconds during an activity.... More.

Intermittent Power-Duration

An an athlete’s power-duration curve provides a representation of steady-state, fixed power, fresh-to-failure efforts  where MPA reduces from peak power to the fixed power.  When partially fatigued, a intermittent power-duration curve can be determined from MPA since it represents the athlete’s fatigue-adjusted peak power at that given instant: Fast-Recovery FatigueThese intermittent curves show the power-duration of an athlete in a fatigued state.  One can consider these as fatigue-adjusted power-duration curves.  What this means is that we can not only determine an athlete’s MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More at a given moment but also establish their TTE  for any given power output above threshold from the partially-fatigued state.  Similarly, we are also able establish the highest power that the athlete can sustain for a given duration while in a fatigued state.  We’ll explore these concepts in a future blog on real-time applications of MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More. When the athlete recovers and MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More rises, the time to recover can be determined.   Generally this means full recovery, but importantly, the time to recover to a reach a given target MPAAlso referred to as TMPA, this is used in the definition of intervals in the Xert Workout Designer and represents... can also be determined.  Establishing the target MPAAlso referred to as TMPA, this is used in the definition of intervals in the Xert Workout Designer and represents... recovery duration is a key component of workout design and we’ll be covering this topic in our next blog: Training Applications and MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More.

Analyzing MPA Data

Reviewing data from an MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More Analysis provides the following information:

  1. Shows where an athlete was at their limit during a race, ride or workout,
  2. Shows how well they were able to manage fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power... in preparation for the final sprint,
  3. Shows how well they were able to manage fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power... during a time-trial,
  4. Shows how a winning/failing attack was executed,
  5. Determines if they “emptied the tank” at the appropriate time,
  6. Shows how difficult an activity was to perform for the athlete,
  7. Shows wattages in context such that efforts near threshold for example, can be assessed in terms of their difficulty,
  8. Exposes other limiters should the athlete have given up or wasn’t able to output the needed power. Examples are heat/dehydration, feeding and others,
  9. Highlights fitness breakthroughs,
  10. Exposes potential PED use, where fitness breakthroughs that are outliers may suggest potential infractions.

Similarly, an athlete’s power output and ability to perform fluctuates due to many reasons:

  1. The athlete may be subject to temporary, day-to-day reduction in fitness as the result of previous training or illness.  This long-term fatigueFatigue represents a reduction in an athlete's ability to produce power.  It either manifests as a reduction in Maximal Power... may impact the ability for the athlete to achieve the same performance level as compared to a recent activity,
  2. The athlete may be subject to other limitations to performance such as overheating, poor nutrition, dehydration, altitude, etc. that may also play a role in reduced performance in comparison to recent activities,
  3. The athlete may have had a fitness breakthroughA fitness breakthrough is achieved when your power reaches or surpasses MPA for longer than 5 seconds during an activity.... More where their fitness has improved over previous activities,
  4. The athlete may be tapering such that fitness is increasing in preparation for an important event,
  5. The athlete may have benefited from either legal or illegal substance use before or during the activity,
  6. The athlete may have detrained and have reduced fitness due to lack of / improper training,
  7. The athlete may have never had points of maximal effortSynonymous with point-of-failure, this refers to moments during an activity where an athlete attempts to produce as much power as....  Many rides, particularly lower intensity or recreational rides, do not have the athlete ever reaching a point-of-failure.  These activities will not provide an accurate measure of an athlete’s fitness signatureIt is represented by three values: Threshold Power (TP),  High Intensity Energy (HIE) and Peak Power (PP). The three fitness values are used... at the time of the activity even though one may obtain it from the data.

When a fitness breakthroughA fitness breakthrough is achieved when your power reaches or surpasses MPA for longer than 5 seconds during an activity.... More is achieved, it generally means that the athlete’s signature can be adjusted upwards such that training workout targets and MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More analysis will now use the updated signature.  Providing feedback on fitness gains and breakthroughs is a great motivator and one could argue that, outside of competitive athletic pursuit, is the main reason why recreational cyclists track and manage their performance data.

Signature Extraction

Just as a fitness signatureIt is represented by three values: Threshold Power (TP),  High Intensity Energy (HIE) and Peak Power (PP). The three fitness values are used... can be obtained with three best-effort power-duration pairs, using regression, the athlete’s fitness signatureIt is represented by three values: Threshold Power (TP),  High Intensity Energy (HIE) and Peak Power (PP). The three fitness values are used... can be extracted from power data containing points of maximal effortSynonymous with point-of-failure, this refers to moments during an activity where an athlete attempts to produce as much power as.... This signature represents the athlete’s fitness at the time of the activity.  Obtaining a fitness signatureIt is represented by three values: Threshold Power (TP),  High Intensity Energy (HIE) and Peak Power (PP). The three fitness values are used... from an activity in this fashion provides numerous benefits:

  1. Athletes no longer need to perform specific fresh-to-failure tests, sometimes multiple tests, to determine their fitness.
  2. Measuring fitness from races, rides or workouts enables faster feedback on progress.
  3. Detraining and fitness losses can be discovered and addressed.
  4. Other limiters can be discovered.

Signature extraction can also be performed intra-ride to determine how one’s signature has been affected by other slow-recovery fatigue factors, fatigue that can’t be recovered during the activity. Based on these types of time-variant analyses, patterns in the variation of an athlete’s signature can be seen and measures to address the decline put in place: Slow-Recovery Fatigue

MPA Analysis with Xert Online

XertTM enables athletes to perform MPA Analysis on activity data.  Power data from an uploaded activity file can be analyzed and information about the athlete or the performance can be assessed.  An example MPA Analysis from Xert Online is shown below: MPA Analysis - Entire Activity In this activity, the athlete performed a series of intervals including sprints and short hill climbs.  Highlighted on the chart are yellow markers indicating points of maximal effort based on the fitness signature: TP = 315W, HIE = 30kJ and PP = 1210W.  As a coach reviewing this analysis, the athlete’s workout was successful as they had intended to reach points-of-failure based on their current signature. Zooming into the area of the activity where the greatest difference between power and MPA was achieved (indicated with green triangles), we can further examine specific occurrences and locations associated with the breakthrough: MPA Analysis - Fitness Breakthrough Using the Extract Signature button, the signature for the activity can be determined: MPA Analysis - Extract Signature This establishes the athlete’s fitness at the time of the activity.  The new signature can be saved to the activity for future reporting or saved to the athlete’s profile such that all future activities will use this signature as their default. In our next blog, we’ll examine how we can train with MPAMPA stands for Maximum Power Available. It is a measure of the maximum power an athlete can generate at a given moment... More.