Big Data

By Adam Pulford, CSCS CTS Pro Level Coach, USAC Level 1 Coach

We’re halfway through the race season. Mountain bikers are coming back from World Cups, roadies are tuning up for nationals, and others pumping out fondos or grinding gravel on the weekends. Many of us who ride, race, and train are fortunate to use multiple bikes for these events and we create an obscene amount of data over a year of riding, let alone a lifetime. Well what are you supposed to do with all that data? And is it all valuable to look at? My quick answers are: capture it, and yes look at it. Why? Read on…

It’s well established that training and racing with a power meter is the best way to monitor exercise intensity, training load, performance, and other matrices. This is particularly cemented in the road cycling culture; however, I often get questions such as “Do I really need a power meter on my mountain bike?” or “Won’t the heart rate monitor let me know about where I’m while racing on the cross bike?” Much of this comes down to budget, I get it. But you should know that capturing this data can lead to great insights about you, as an athlete. Don’t get me wrong: we can get people fit and coach world champions without power meters, but as technology improves and more cost-effective power meters come to market, there are compelling reasons to capture as much data as possible. Over the next few paragraphs, I’ll shed some light on why it’s ideal to use a power meter on more, or all, of your bikes if you’re looking to gain that cutting edge.

Now, before we dive into the nerdy coach talk, please know that my whole aim for this writing is to educate you, the reader, then get a working game plan so you are equipped to optimally prepare to reach your goals. With many power meters and data monitoring devices on the market these days, it’s hard to sift through all the options to know what is best. Let’s take a look at some options while keeping the big picture, as well as your budget, in mind.  

Big Data

The phrase “Big Data” is popular and catchy in our data-driven world. But what is it? Google defines Big Data as “extremely large data sets that may be analyzed computationally to reveal patterns, trends, and associations, especially relating to human behavior and interactions.” The inner nerd within all of us just smiled at that. We’re entering a unique period in exercise physiology where we can really start to capture, quantify, and organize big data sets, especially on a bicycle, where we can computationally reveal the trends of what all the miles, intervals, and recovery blocks are doing. Thanks to these exciting advances, more and more people are investing their money into a power meter. With each pedal stroke, we get hundreds of data points, such as power, heart rate, cadence, torque, GPS location, temperature, and R/L pedal mechanics for some units. But then we have to know what to do with this data. Lucky for us, there are many people (far more intelligent than me) who have created software that can not only read all of these data points, but also organize them in a way that reports back to us how the ride went, what the athlete actually did, and gives insight into training thresholds, maximums, and current states of “freshness.” More exciting still: we’re getting into PREDICTIVE MODELING OF PERFORMANCE for athletes with these big data sets and history of training files. Some of the software options out there include the new SRMX, Golden Cheetah, Training Peaks WKO4, My Daily Plan, Strava’s online analytics, and a few others. SRM was one of the first to bring this type of technology to cyclists, not only with the first commercial power meter, but a cycling computer with real-time feedback and an analytical software called SRMWin to organize rider’s data. No other company had software to do that. So, what the German company created was more than just a power meter, it was a complete SRM Training System. They keep evolving with the market, this time launching the new SRMX software. It has a lot to offer, so much that it’s best to look at few key features on a higher level, then dive in deep on the next article. With that being said, let’s dive right in!


On top of storing all historical files for review at any time, the new SRMX has many upgrades as well as tried-and-true matrices including auto FTP calculation, HR-to-Power Slope Charts, Critical Power Curve analytics, custom training zones, and mapping features. The Critical Power Chart is seen below:

Very briefly, what you’re looking at above is a power duration curve for your current ride compared to Critical Power and historical data. Power is on the y-axis, time is on the x-axis. Short, hard efforts are represented on the left, while the longer, lower power efforts are shown as you move to the right side of the graph. This is one of the most useful charts because it not only shows you the ride summary of the ride you just did, but compares it to your best historical efforts ever along with two other (more recent) time periods. In short, it gives you the most information on yourself in one chart. When you actually use SRMX, you’ll see that as you mouse over the dotted lines, you can locate the exact file from which the historical data comes from.

Social Sharing

For all of you social butterflies out there, SRMX now caters to today’s connected communities including upload capabilities to Strava, Training Peaks, and a host of other online platforms:

Training File Analysis

For us tech heads, we have a clean and robust single line file to analyze each second of each ride with the ability to highlight key sections, intervals, zoom in, and more. Paired best with the SRM PC8 wireless computer with GPS, this whole SRM Training System syncs and talks to itself for uploading if you want it to.

PC8 Device Agent

The final component of the SRM Training System is the PC8 Device Agent: a simple app that you download to your computer which allows you to customize your PC8 screen the way you want it to look:

This means no fussing around with pushing a thousand buttons to find that one item you want, buried deep in some menu that you forget each time… just plug the PC8 into your lap top, click and drag, file and save!

Be Smart

In terms of a seamless “smart training system,” it has my coaching approval. Of course, with anything new, it will require some time for the user to play around and learn the subtleties, but ease of use comes quickly for even with little tech savviness.

I will admit: There are some great analytical applications on the market today with tons of tools to allow the most data driven cyclists to really dig into their training. But, SRM offers their SRMX software with all the bells and whistles for free. It’s constantly being updated with new features and analytics to improve user experience to help you train at your best.

Accuracy and Consistency

There has been plenty of advice that consistency is the main consideration when deciding on which power meter to purchase, myself included on that. But what I am finding is while that is still true, once you start using two different branded power meters on two different bikes, both of which are consistent within themselves, but both having different accuracies, your perfect data now starts to become imperfect. SRM’s power meter measurement system has error of less than 1%, where as other competitors can be +/- 2-5%. In addition, other power meters can have more deflections in the power data, skew the max efforts (or longer efforts), and leave your big data quite noisy. Couple that with firmware needing to be updated and dead batteries that give wonky power readings before it zaps out, there’s some cleaning up to do on the back side of the ride. Continual attention to watching this data, correcting for the errors, and checking it against what you know to be accurate is tedious. Additionally, having two different power meters with two different accuracies, but consistent within themselves, does go against the consistency advice: the sets of power data are not consistent to each other. Therefore, if you are to get multiple power meters, I do advise to get the same brand to be consistent across the board.

I’m trying to build the case for capturing all pieces of data that we can, on the road, and off-road. When we do so, with accurate and consistent power meters, we start to build big sets of data that will start to show the trends of fitness and performance specific to the athlete (i.e. you), as well as the threshold power, max powers, and limits of the current training period. Finally, we can use predictive modeling of what has worked and what hasn’t to build the future fitness. But, that data is only as rich as it is accurate and doesn’t have big missing gaps.

Cost of Multiple Power Meters: The Real Deal

Let’s face it: cycling is an expensive endeavor. Bikes, tires, maintenance, food, sport nutrition… it all adds up. Throw the power meter on too, and we’re racking up a big bill. Two power meters? Three? It can get excessive…

Should you have multiple power meters? Well, if you have the means, the curiosity, and want the best set-up possible to monitor your cycling performance, yes, I recommend it. However, I will encourage you to heed my advice on going with most consistent AND accurate power meter you can afford – and be consistent with the same brand across all of your bikes to have as consistent, reliable data as possible. The reason I say this goes back to our big data argument and the goal of keeping your data as clean as possible. But, multiple power meters, especially SRM power meters, can get expensive, so what’s the other option?

The SRM Training System is still the gold standard recommended by many coaches, including myself. if you’re on a budget, they have lower cost power meters with the high level of accuracy and consistency you’d expect. I know I am writing for SRM, but I’m doing so by choice, to get word out about their product. The company and products are evolving with cost effective options and great software to analyze data. There are other, and cheaper options out there. But one must factor in the cost of other aspects when looking at the total price. With other units, you should factor in a few other costs, including the following: purchasing software to review your data (for some), batteries that drain faster, and repairs outside of normal warranty issues. Let’s not forget the cost of your time to clean up noisy data when bad data occurs. If you want the most accurate, consistent power meter with great customer service coupled with a complete training system that will analyze and house all your data, think more about the SRM Training System.

In Summary

The whole point of this long, somewhat geeky article, was to educate and deliver a plan on how you monitor and organize your cycling data for 2017 and beyond. I want you to have the facts, along with some opinion from those of us working with these gadgets each day. Power meters are fantastic things for cyclists, and if you have performance goals on the bike, get one. I encourage it. Establish what your budget is, and go with the most accurate and consistent choice. SRM is the best I have seen out there, and if your budget is for only one, I recommend only buying one power meter for now but make it good.  If you’re thinking of a second power meter for another bike, buy the same model you have, or go with another SRM. Your big data will be cleaner, and if you have a coach, he or she will thank you greatly.