by Marci Titus Hall

While analyzing my mountain bike race data recently I began to wonder what was going on with my power during the race. The power graph is always extremely choppy with occasional peaks yet much lower than expected power averages. All the work of mountain bike racing doesn’t seem to be translating to power. A mountain bike race comes down to the rider’s fitness, technical skills, luck and finesse, in addition to the course terrain, weather, and course conditions. In a nutshell it is all about the rider’s ability to ride, as fast and efficiently as possible, over, under, or around any obstacle, any incline or decline, without help or team support, to the finish line. And as I compare my power graphs from my rides and races off-road I realize that there is more to mountain bike effort than meets the eye. But how does this translate to power output? It isn’t as straight forward as I once thought. Here is what is really going on during a mountain bike race.

The start of a mountain bike race is very similar to that of a crit race – it goes fast and furious from the gun – faster the closer you are staged to the front, regardless of roots, rocks, gravel or grass. A typical mountain bike race brings the racers from a field/road area into single track as soon as possible requiring the peloton to go from the sprawl of anything from 2 to 9 racers wide, down to single-file where unless you were among the top five into single track, there will be waiting. As strange as it sounds you can actually find yourself standing still, one foot on the ground, waiting in a traffic jam for your chance to join the race; even the most competitive racer can find themselves in this situation for one reason or another and have little choice about the matter. Impending traffic issues can make the start of the race even faster as racers will surge from the line determined to be first to single track – doing so can secure a racer’s position, while not making it can definitely ensure a heck of a lot more work to make up lost ground – if at all possible.

Once in the trail, riding through single track is all about technical skill and finesse – a smooth rider (even amongst riders of the same fitness level) can pull away and gain time over competitors. Meandering through tight turns, rock gardens, creek crossings, log jams, low hanging branches, mud bogs, and countless additional obstacles that can be found along a good race course with speed, and finesse, i.e. efficiency, is the name of the game when it comes to mountain bike racing. Even a few seconds gained here and there can translate to minutes gained ahead of competition - but not necessarily show up as anything impressive when it comes to power output – yet a rider can separate themselves from the fray and gain ground. While visa versa, a rider who is lacks finesse, or is riding choppy may be putting out greater power output but can waste energy, lose ground, and hold up riders behind who are then forced to wait for a safe place to pass where they will need to expend even more energy to ride into grass, through a bush, up an embankment or wherever in order to get around a slower rider. Not to mention the fitness and skill required to climb a technical mountainous ascent which could include water bar crossings and lose gravel requiring smooth pedaling and weight balance to maintain traction - not necessarily high power output. Only to be rivaled by the strength, muscular endurance, and guts required for descending a mountainous course, which may end up looking like recovery on the power graph when it is nothing of the sort. All of these factors come into play during any given mountain bike race, yet most of them remain unaccounted for among the power data.

How do you demystify the power data and translate mountain bike race data into fitness gains for increased cycling efficiency for off-road racing? Go above and beyond your power data by going a little harder or a little longer. Specifically I recommend looking for 3 aspects of each race file and creating intervals to mimic and build on each 3 areas in order to gain fitness. The more fitness you possess the more likely you are to ride longer with finesse through tough technical terrain.

Start Power: Check out your power output from-the-gun by examining the first 3-4 minutes of the start of each race – for at least as long as your power is increasing. Use the average of this start power (+ and - 5 watts) to create a power range for an effort that you will sustain for 4 minute intervals (with 4 minutes rest between intervals). Repeat this interval until you can no longer sustain minus 10 watts of your average start power. Do this on a dirt climb trying to mimic your typical race start terrain.

Peak Power Output: Check out the highest peaks achieved during racing by reducing the smoothing factor and counting each time your power goes over your predetermined 30-second peak power record wattage. Then determine how many times per hour you reached that peak. (If the number is greater than 6/hr, use your 5-second peak power record wattage). Use the number you determine (per hour) to establish how many 1-minute intervals to repeat (at 30-second peak power wattage) per hour for a 2-3 hour ride (with 10-minutes rest between intervals). Do these intervals for the duration of the ride until you can no longer hit the peak power even momentarily.

Kilojoules: Check out the total Kilojoules (kj) for each race. Kilojoules represent the total amount of work performed for the duration of the ride. Though this number, like all power data, is still not able to take in to consideration the muscular work of technical riding that isn’t going into the pedals, it is still the closest thing we have to determining work load on the bike. To train with kilojoules take the average of the numbers you achieve while racing your typical race length. You can use this number to mimic a ride of the same workload on any terrain w/o worrying about specific power outputs. Ride until you reach your designated kj by either riding one way until you reach the halfway mark and then heading home, or doing small loops, or using an indoor trainer. This effort can be used along with either of the other interval parameters and should be done once a week either on or off-road training working on flats or climbs as needed.

Each of these data points/intervals should be repeated weekly during build training weeks and interspersed with recovery as needed. By keeping track of these three aspects of your racing and training you can track fitness gains as well as areas that need improvement.