This article covers all the metrics in TrainingPeaks and how they are calculated. Metric Explanation Calculation TSS - Training Stress Score A composite score estimating the training load of a workout based on intensity and duration. TSS = (Duration (s) x NP x IF) / (FTP x 3600) x 100 IF - Intensity Factor A measure of workout intensity relative to your Functional Threshold (FTP/CP/LT). IF = NP / FTP NP - Normalized Power An adjusted power value that accounts for variability in effort, better reflecting physiological cost than average power. Calculated by smoothing power with a 30s rolling average, raising to the 4th power, averaging, then taking the 4th root. EF - Efficiency Factor The ratio of Normalized Power (or Pace) to Heart Rate; used to track aerobic efficiency. EF = NP (or Normalized Graded Pace) / Average HR VI - Variability Index A measure of pacing smoothness: NP divided by average power. Values >1.05 suggest inconsistent pacing. VI = NP / Average Power CTL - Chronic Training Load The rolling average of daily TSS over ~42 days, representing long-term fitness. CTL = exponentially weighted average of daily TSS over 42 days ATL - Acute Training Load The rolling average of daily TSS over ~7 days, representing short-term fatigue. ATL = exponentially weighted average of daily TSS over 7 days TSB - Training Stress Balance The difference between CTL and ATL; positive values suggest freshness, negative values indicate fatigue. TSB = CTL - ATL Pw:Hr - Power-to-Heart Rate Decoupling The percentage drift between power (or pace) and heart rate over steady-state efforts; indicates aerobic durability. Pw:Hr = (Power:HR ratio in 2nd half / ratio in 1st half - 1) x 100 w'bal - Work Capacity Balance Tracks remaining anaerobic work capacity during an effort, based on critical power modeling. Calculated using critical power model: W'bal = W' - ∑ (work above CP - recovery below CP) rTSS - Running TSS Running-specific TSS based on pace, heart rate, or power, accounting for intensity and duration. rTSS = (Duration x IF2 x 100) / (Reference pace/power threshold) sTSS - Swim TSS Swimming-specific TSS, often derived from pace and threshold pace. sTSS = (Duration √ó IF2 x 100) / (Threshold swim pace) FTP - Functional Threshold Power The highest average power an athlete can sustain for ~1 hour; used to scale power zones. Estimated via 60-min test, or commonly 95% of 20-min best effort. LTHR - Lactate Threshold Heart Rate The highest heart rate an athlete can sustain for ~1 hour; used to set HR training zones. Determined from race data or field testing (e.g., 30-60 min TT).

Your RPE stands for Rate of Perceived Exertion and refers to how you feel during a training effort. This is judged on a scale from 1-10 (1 = very easy, 10 = maximum). The below table provides an overview of the RPE scale to help you judge your own training. The table below is an RPE scale that can be applied to all sports (cycling, running and swimming). If you are unsure how hard a workout should feel then refer to this table. If you are finding the workouts feel easy when they should feel hard, you will likely need to update your threshold and training zones. Training Zone RPE Rate (/10) RPE Description Zone 1: Recovery ​< 2 This should almost feel like walking. Nasal breathing should be easy along with maintaining conversation. Zone 2: Endurance 3-4 You can ride anywhere in zone 2 for aerobic endurance rides. This should feel like your ‘all-day’ pace and breathing rate should be under control. Plus, you will find you can maintain a conversation at this intensity. Zone 3: Tempo 6-7 Training at this intensity should not feel to taxing. However, as the workout duration increase it will become more fatiguing. Conversation is still possible, but you will notice you are taking more breaths between words. Zone 4: Threshold 7-8 Threshold efforts are where your longer time trial pace sits (40km or 25miles). You will feel a continues suffering during these intervals so conversation would be very hard as your depth of breathing will increase also. Zone 5: VO2max 8-9 ​Breathing will begin to feel quite heavy during the intervals. You will notice towards the end a lot of lactic acid has built up in the body. Conversation would be very difficult to hold at this intensity. Zone 6: Anaerobic 9-10 At this intensity conversation is not possible. You will experience very heavy breathing rate, and may even find your lungs burn slightly. If you want further help please contact BCA with the provided below. Email: info@breakawaycoachingandanalytics.com

Under/over intervals are quite popular among cyclists—but what exactly are they, and what value do they offer for your performance? What is the benefit of doing under/overs? When you go above your threshold, your body produces a lot of metabolic waste products (e.g. hydrogen ions). When you return to riding below your threshold, your body works to clear this waste and shuttle lactate to be reused as energy. As you complete these intervals over time, you’ll notice that you recover more quickly after going above your threshold. How far above and below my threshold should I go? There is a grey zone roughly 5% above and below your threshold where your body transitions from heavy to severe exercise intensities. Therefore, you must make sure you go clearly above and below this grey zone. That’s why these intervals are often planned at around Zone 3 (for the “under”) and approximately 110% of FTP (Zone 5 for the “over”). How should I move from Zone 3 to Zone 5? When accelerating, alternate between seated and standing efforts. Seated accelerations place additional stress on the knees, which can be beneficial for strengthening these areas, but may also increase the risk of injury if too much stress is applied. How long should each under and over section be? It can take between 1–3 minutes for the body to fully adapt to the intensity of exercise. Therefore, if the intervals are shorter than 60 seconds, it’s possible you’re not getting the full benefit from the session. You would likely be riding in heart rate Zone 4 for much of the under/over intervals. Are these better than normal threshold intervals? Not necessarily. Under/over intervals stress your body in a different way and produce different adaptations. But this doesn’t mean they’re better or worse overall. For example, if you want to improve your ability to sustain threshold intensity for longer durations, both steady threshold intervals and under/over workouts can be helpful. If you have any questions, please don’t hesitate to email me.  Email: info@breakaway-coaching.com