Brain Endurance Training

First established in the landmark 2009 study, brain endurance training (BET) has been shown in fMRI brain scans and numerous peer-reviewed studies to improve athletic performance by targeting the part of the brain responsible for managing fatigue, decision making and the suppression of undesirable impulses aka will power.

Research done in 2015 by Rewire’s scientific advisor, Walter Staiano showed that brain training is highly effective in improving endurance performance when combined with traditional physical training. Those in the brain-training group had a 3x improvement in time to exhaustion (TTE) than the control group (+126% compared to +42%) over a 12 week training period.

In order to measure your performance, the Rewire system records all of the traditional physiological metrics such as average heart rate, average and normalized power, intensity factor (IF), training stress score (TSS), cadence, interval time and total workout time. Additionally, the system also tracks your mental performance including response time, accuracy, RPE, session RPE, and a proprietary metric called your perception gap. Your Perception Gap is the difference between your self-rated RPE (how hard you think you worked) compared with your expected RPE based on how hard you actually worked under the conditions of mental fatigue, using data from the power meter and heart rate monitor. By measuring the difference between your perception vs. your actual physical performance the Rewire system establishes a methodology whereby you can measure your mental performance over time. The goal is to reduce the gap in your perception when training or competing under mentally fatiguing situations so that your mind is not a limiter to achieving your true athletic potential.

Your brain training workout assessment is an overall measure of your performance while under increased mental fatigue.   Pay close attention to your Perception Gap score as this will be the strongest indicator of adaptation to mental load.  Positive perception gap numbers show a strong mental resilience to cognitive fatigue whereas negative numbers show a gap in your perception.  Additionally, your Answer Rate (RSC) is a  cognitive measure that tracks your ability to maintain focus during the cognitive task questions i.e. it’s a calculation that tracks your accuracy compared to your reaction time.  Your performance level is a qualitative rating that is based on your perception gap score e.g. “Champion Level range” for this workout.

Your cognitive metrics are focused on your overall mental performance during the cognitive task portions of the workout.   The following is a breakdown of each of the metrics.   Pay close attention to the number of Lapses, Accuracy, and Trained Reaction Time as they are good indicators of your current level of cognitive performance.

  • Reaction Time (Psychological Measure):  Reaction time is the time measured in seconds that it takes the athlete to respond correctly to a given mental question or challenge.
  • Accuracy (Psychological Measure): Accuracy is the percentage of correct answers compared to the total number of questions in a mental challenge for a given interval or workout.
  • Answer Rate (Psychological Measure): Measures the ability of the athlete to maintain concentration during cognitive tests. The statistics included in the formula are the athlete’s total correct answers (per workout) divided by the SUM of their response time (per workout).
  • Lapses (Psychological Measure): Lapse time counts the total number of slower than average responses to brain training questions.  For brain training, lapses are counted for any response slower than 2 seconds to a cognitive task question.  A higher than normal number of lapses is a good indicator of increased mental fatigue.
  • Trained Reaction Time (Psychological Measure): TRT is the range of all responses from 100ms to 2 seconds and represents the reaction time that is improved upon with continual brain training.
  • Perception Gap (Proprietary Psychological Measure): The perception gap (P-Gap) provides the athlete with a quantitative measurement that compares their subjective (self-rated) RPE with their objective or expected RPE based on their physical output generated during the workout measured in watts and or average heart rate.  A negative score indicates a gap in the athlete’s perception of the actual level of physical effort during the workout.  A neutral (or “0”) score indicates an accurate perception of the effort during the workout and a positive score indicates a strong level of resilience to mental fatigue.
  • Load Index (Proprietary Physiological & Psychological Measure):  Load index is a measure of the total mental stress during a workout.  It combines a number of cognitive and psychological measures from the workout with the highest possible score of 20 (meaning an extreme level of mental stress) vs. the lowest possible score of 0 (meaning no mental stress).

Your physical metrics are focused on your overall physical effort during the workout.   The following is a breakdown of each of the metrics tracked.   Pay close attention to your session RPE (sRPE) and RPE compared your power metrics as this will give you a good sense as to your perception vs. the actual level of physical effort for this workout.

  • Functional Threshold Power (FTP):  Functional Threshold Power is an estimation of the highest power (measured in watts) that a rider can maintain in a quasi-steady state without fatiguing for approximately one hour.
  • Average Power:  Average power in watts over the course of the workout and per interval.
  • Normalized Power: is a metric to quantify training intensity with power data and takes into account the variability in power output using a 30-second rolling average which can be more accurate than average power especially for longer efforts that have a higher degree of variability of power output and effort.   Efforts less than 20 min in duration or with less variability in terms of power output requirements may not benefit from NP vs average power in terms of an accurate assessment of training intensity.
  • Lactate Threshold Heart Rate (LTHR): Lactate threshold is the exercise intensity in which the release of lactate into the blood first begins to exceed its rate of removal.   For most athletes, LTHR is typically 20 heartbeats per minute above the steady aerobic threshold. Read more about LTHR training here.
  • Average Heart Rate:  Average heart rate measured in heartbeats per minute over the course of the workout and per interval.
  • Heart Rate Variability (HRV):  Heart rate variability is the measure of the beat-to-beat variability between heartbeats.  Known as a very reliable measure of both physiological and psychological stress it is used as a standard metric for training across most sports.   Rewire uses the gold standard calculation for HRV known as rMSSD which stands for the root mean square of successive differences.  This is the same standard used by many well-known HRV apps and tools though it is useful to note that there is no standard for the scale factor applied to HRV which is why from app-to-app the measurements are slightly different.   You may also override the Rewire’s HRV calculation by syncing to Apple Health or Google Fit and selecting the “Use HRV data from this source” found under integration settings.  Read more about HRV measurements and the science behind it here.
  • Cycling Cadence: cycling cadence is the number of pedal revolutions per minute.  Note that Rewire provides limited support for this metric depending upon the power or smart training device used. 
  • Rate of Perceived Exertion (RPE): the rating of perceived exertion otherwise known as RPE, was first developed by Gunnar Borg as a subjective measurement system used by sports coaches to assess the intensity of training and competition.  Rewire uses the 15 point Borg RPE scale which was specifically designed to measure the perception of effort during physical training.   Why 6 – 20?   This scale was originally modeled after ranges of heart rate from 60 BPM to 200 BMP.  This scale has been validated over decades of research and remains the gold standard for subjective measurement of both effort and pain.
  • Session RPE (sRPE): Session RPE is a calculation designed to measure the training load based on the athlete’s subjective RPE rating for the workout.  The calculation is made by multiplying the athlete’s RPE value x the number of minutes in the workout.
  • Training Stress Score (TSS): Used as a measure for internal training load based on power output. TSS is a composite number that takes into account the duration(t) and intensity(IF) of a workout to arrive at a single estimate of the overall training load and physiological stress created by that training session.
  • Intensity Factor (IF): Intensity Factor (IF) is the ratio of the Normalized Power with the athlete’s Functional Threshold Power (FTP) for a given workout.  Because IF is the ratio between normalized power and the athletes current FTP it takes into account changes in fitness over time as well as differences between individuals. 

The intervals section of your workout metrics screen is a great way to review both your cognitive and physical performance for each interval of the workout and includes the following:

  • Time:  The total duration of the interval.
  • Power: Your average power for the interval.
  • HR: Your average heart rate for the interval.
  • Lapses:  The number of cognitive lapses for the interval (brain training intervals only).
  • RT: Your average reaction time for each cognitive question during the interval (brain training intervals only).
  • Accuracy: Your accuracy percentage for the cognitive task questions during the interval (brain training intervals only).