A.B.C. - Always Be Cycling! Cracking the Codes of Modern Cycling Metrics
Posted by Andrew Davidson on September 3, 2025
The world of watts and other modern cycling metrics can often feel overwhelming and complicated. Perhaps you’re just getting into cycling and using tools like power meters, heart rate monitors and cycling computers for the first time - or you’ve had them for a while but were never really sure what to make of all the numbers and letters being thrown at you. The list of two and three-letter abbreviations and acronyms can seem endless… NP, kJ, IS, FTP, TSS, W/kj, RPM. Whether on your computer screen during an activity or post-race upload, using apps like Strava or Training Peaks, there’s always plenty to dissect. With that being said, it doesn’t have to feel like a math exam you didn’t prepare for every time you peek at your stats. We’re here to shed some light on a handful of the most commonly referenced cycling metrics and how to apply them to get the most out of your riding.
The winning numbers from Cameron Jones’ 2025 Unbound Gravel victory!
The foundation of the vast majority of the cycling metrics we’ll discuss is based on power data, which is delivered courtesy of your 4iiii power meter, and displayed on your choice of cycling computer, smart watch, phone, etc. The beauty of using a power meter as your primary training tool is its objective measurement. Unlike heart rate, which is affected by factors like fatigue, temperature, and stress, power is an absolute measurement of your work. This makes it the most reliable way to track your progress over time. With that being said, let’s get into the finer details!
Instantaneous Power (W): This is the power data you’re seeing on your computer screen while riding. The most immediate power reading is every 1-second, which will fluctuate rapidly - most riders will opt to set their power reading to 3-second or 5-second (avg) power when riding, as it’s easier to monitor in real time, and still provides an accurate reflection of the effort. A 3-second average works best for shorter intervals, while a 5-second average may be better suited to longer, steadier efforts.
Average Power: Here we’re referencing the average power output over the entirety of a ride or a specific period, like a single interval. It’s the simplest and most straightforward reflection of the total work done, in watts, divided by the total time. It will include the periods of zero power output in the equation (when coasting down a descent, for example). It’s most useful on steady, consistent efforts, such as an indoor trainer session or time trial, when average power and normalized power can be very similar.
Normalized Power (NP): Normalized Power is in the same family as average power, but a more advanced metric that accounts for fluctuations in the ride, providing a more accurate reflection of the physiological cost of the entire effort. It’s an average power calculation that considers all input factors and estimates the power you could have maintained at a steady pace to produce the same physiological stress. It de-emphasizes the moments of low power and gives greater weight to the short, high-intensity periods to better reflect the strain of the ride. It’s highly useful for understanding the overall training load and metabolic stress of rides with high variability, such as an interval training session or hilly race, where efforts fluctuate between low and high power output.
Normalized Power (NP) factors out more of the “dead spots” of a ride or race, such as time spent coasting on a descent, to give a better reflection of the true demands of the effort.
Max Power: This metric is pretty straightforward and fun to chase; it’s the highest wattage output recorded during a given ride. Just like average power, most cycling computers will allow you to adjust the time frame that is measured for your max power, 1-second, 3-second, 5-second, etc. Additionally, most training apps will show your max power at a wide range of timed intervals. Functionally, 3-second max power or longer will be the most useful for working on sprints and short, sharp efforts. It’s fun to experiment with different cadences when doing spring workouts, to see and feel the potential advantages of higher and lower leg speed when doing a max power effort.
Cadence (RPM): Cadence is the term used to describe your pedalling rate, measured in revolutions per minute (RPM), indicating how fast the pedals are completing a full revolution. While there is no “right” cadence, it’s a good rule of thumb to work on both ends of the spectrum, low and high, to develop efficiency and stamina at a wide range of cadences. Somewhere around 50-60rpm would be considered the low end of the spectrum, while 110-120rpm would be the high end, for most riders. Track cyclists and BMX riders would be an exception, as they ride on single-speed bikes and can require fluid pedalling well into the 140+rpm range, but for most of us, if we master a smooth pedal stroke ranging 60-110rpm, we’d be in great shape! It helps to work on both ends of the cadence spectrum, as there will ultimately be times when you’re forced to do low rpm’s up a long, steep climb, while at other times you’ll be flying along with a tailwind on a false-flat downhill in your biggest gear, wanting to spin it out further. Low cadence is known to be more demanding from a muscular standpoint, whereas high cadence is more taxing of the aerobic system -which is another reason it’s worth mixing it up. A classic workout for improving or maintaining a fluid rpm range is a “cadence pyramid”, in which you start at a low rpm, and gradually increase it by 10rpm every 30 seconds to a minute, several times over, before working your way back down. It might look something like this:
1min @ 60rpm, 70rpm, 80rpm, 90rpm, 100rpm, 110rpm, 100rpm, 90rpm, 80rpm, 70rpm, 60rpm. The goal is to keep a smooth pedal stroke (not bouncing in the saddle) at all stages of the pyramid. It’s a great exercise to do at the start of a workout to ensure you’re thinking of efficiency for the remainder of the ride.
We’d be smiling too if we could produce the kind of numbers Cameron Jones’ did during his recent ride at the 2025 Lauf Gravel Worlds, sprinting to a 3rd place finish.
Watts per Kilogram (W/kg): Also known as one’s “power-to-weight ratio,” watts/kg measures a rider’s power output relative to the body weight, by dividing their watts over a given period (interval or ride) by their total weight in kilograms. This information is mostly referenced for climbing performances and comparing riders/racers of different sizes, with a higher W/Kg typically translating to faster climbing ability. For example, a rider who can maintain 270W for a 20-minute climb while weighing 63kg would be able to average 4.3W/kg. In contrast, another rider who can hold a significantly higher wattage of 320W for the same climb but weighs 80kg would have a lower power-to-weight ratio of 4W/kg. Other factors like aerodynamics can also come into play, but generally speaking, the higher one’s watts per kilogram ratio, the faster one will be able to get up longer, sustained climbs. One can increase this ratio by either adding watts or decreasing their weight. It’s worth mentioning, in a sport that’s often fixated on weight to an unhealthy degree, that adding watts would be the ideal approach to improving your climbing, as it will also benefit your output on the flatter terrain. If you go with the weight loss approach, just make sure you’re doing so in a sustainable and healthy way, while still fueling properly!
W/kg, a formula that comes into play most significantly once the terrain tilts upward.
Functional Threshold Power (FTP): This term refers to the power that one can theoretically sustain for one hour. It’s often used as a benchmark for setting your personalized training zones, and is established through specific tests, such as a ramp test, 8-minute test, or 20-minute test. Each test has its specific protocol to determine your FTP, and is best performed on an indoor trainer or sustained climb that allows for an uninterrupted effort. Once your FTP is known, the rest of your training zones, such as your Recovery, Endurance, Threshold, VO2, etc, can be determined and allow for accurate training efforts. For example, if your FTP is 225W, your Endurance or Zone 2 range would be approximately 126W-169W (56-75% of FTP). Armed with this knowledge, you can ensure you’re sticking to your training plan when it calls for a longer day in the saddle to build your endurance. It’s worth re-testing your FTP periodically to know when it’s time to adjust your training zones, and/or making use of apps that are able to automatically update your FTP with the adaptive learning that’s now available.
Intensity Factor (IF) will vary depending on the demands of your rides - an XCO MTB race, for example, would rank extremely high on the IF scale, compared to an endurance ride.
Intensity Factor (IF): Intensity Factor is a cycling metric that expresses the relative intensity of a ride by dividing your Normalized Power (NP) for the ride by your Functional Threshold Power (FTP). An IF of 1.0 indicates a ride was performed at your FTP, while values below 1.0 show an easier effort, and values above 1.0 represent a harder effort relative to your FTP. IF helps quickly assess workout difficulty, compare different rides, and track fitness improvements, as it shows how hard a given effort was compared to your sustainable power limit. IF can help riders avoid training too monotonously by serving as a reference to ensure a varied training stimulus. For example, it can be used to guide the intensity of a long ride (low IF) versus a shorter, high-intensity ride (high IF).
Training Stress Score (TSS): Training Stress Score, or TSS, is a number that quantifies the physiological stress and total workload of a workout by combining its intensity and duration into a single score. It essentially blends all the data to give an overall assessment of the effort. It’s calculated using Normalized Power (NP), Intensity Factor (IF), ride duration, and your Functional Threshold Power (FTP). TSS provides a way to manage training load and avoid overtraining by indicating how hard a session was on your body. A higher TSS value signifies a more demanding workout, where 100 TSS points represents one hour of cycling at your FTP. As we can see in the photo of 4iiii athlete Cameron Jones’ Unbound Gravel stats, he logged an incredible TSS of 447.3, a blistering day out for the biggest win of his career thus far! By tracking weekly or monthly TSS, you or your coach can also monitor trends in fatigue and know when it’s time to reduce the training load or take some time to recover.
As you gain a better understanding of the work (kJ) your body puts out during training and races, the better equipped you are to formulate proper fueling strategies.
Work (kJ): Kilojoules, or kJ, are a unit of energy, representing the total work done over a period of time, with the formula for calculation being: (average power in watts x time in seconds) / 1000. One kJ is approximately equivalent to a kilocalorie (kcal), the common unit of energy for nutrition. While the kJ metric reflects the mechanical work performed to turn the pedals, not the total energy your body has consumed, it’s still quite helpful in planning a fueling strategy for rides and races, and when considering post-ride recovery needs.
Check out the 4iiii power meters trusted by world-class athletes and weekend warriors alike here.
