A Tale of Two Files

Dickens, am I right? Well onto the interesting stuff...or rather, stuff, we'll let you decide if it's interesting.

File 1 - Marathon MTB Race at 2000m Elevation

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Athlete Metrics

  • 61 kg
  • 180 bpm threshold HR
  • 320w FTP (at race elevation)

Race Load

  • 6:48 race time
  • 4998 kJ
  • 377 TSS
  • 205w average power, 246w normalized power
  • 1.2 variability index
  • 156 bpm average HR (87% of threshold HR)
  • -0.64% Pw:Hr drift

Peak Powers

  • 30 sec - 543w, 83rpm (170% FTP, produced at start)
  • 60 sec - 477w, 82rpm (149% FTP, produced at start)
  • 5 min - 347w, 91rpm (108% FTP, 824 kJ completed prior)
  • 20 min - 280w, 90rpm (88% FTP, 824 kJ completed prior)
  • 60 min - 240w, 92rpm (75% FTP, 3042 kJ completed prior)

File 2 - European Climbing Road Race at Sea Level

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Athlete Metrics

  • 60 kg
  • 183 bpm threshold HR
  • 360w FTP (at race elevation)

Race Load

  • 3:47 race time
  • 3112 kJ
  • 283 TSS
  • 229w average power, 286w normalized power
  • 1.25 variability index
  • No HR metrics

Peak Powers

  • 30 sec - 556w, 89rpm (157% FTP, 2612 kJ completed prior)
  • 60 sec - 485w, 89rpm (135% FTP, 2601 kJ completed prior)
  • 5 min - 393w, 88rpm (109% FTP, 2560 kJ completed prior)
  • 20 min - 364w, 86rpm (101% FTP, 2560 kJ completed prior)
  • 60 min - 297w, 88rpm (83% FTP, 2053 kJ completed prior)

The Punch Line

It is what you make of it, huh, so what do you make of it? Well in a lot of ways, I’d say the demands of these races are super similar. On a simple level, physiologically, both races/tasks demand excellent aerobic efficiency for success. Meaning the efforts the athlete needs to make, must not take so much out of the athlete, that they cannot repeat them, and that they cannot complete the total workload at a high effort. It is 3000 to 5000 kJ of energy demand, and meeting that demand is the baseline minimum. This is in contrast to say a short track or cross country MTB race, where as total workload goes down, the absolute intensity goes up. In both of these races, a big common factor is that the driver in the result is not absolute, one time, power for say five or twenty minutes (more like a TT or a shorter event), but the ability to absorb a large workload and then go fast enough to be competitive. In a lot of ways I think about races like this as, “weathering the storm” races. Whoever can weather the storm best, and then go still fast, wins.

Now, as the cliché tells us, the devil is in the details. So while on a simple level these races are about the same thing, handling a big aerobic workload, when you drill a bit deeper, the differences show up. First off, just looking at the two power files, visually we see that the road race is actually more stochastic, and just consistently having more oscillations in power. This is a key component of road racing, especially in Europe. You can look at the first 2.5 hours of the race and say, “ok, 220w average, that’s what I train for”. What is easy to miss is, that there is a < 5sec burst over 400w, probably every 5-8 min on average. None of those efforts in isolation are challenging for this athlete, but what they do is add up to a significant amount of cumulative time over threshold, which shifts things metabolically, as well as adds to muscle fiber fatigue. Both of these are things, which are totally manageable, but they increase the carbohydrate/glucose demands on what the athlete needs to take in exogenously, and if they haven’t trained to do the workload prior to the race finish with some of it coming from anaerobic efforts, they will be more tapped than expected. That is an initial big difference right off the bat. The marathon MTB race, you can see the 30 sec and 60 sec peak powers are pretty much the same as the road race, but they happen right at the start and then it’s over. As the race goes on, you can see the file just gets smoother and smoother. The competitive power under fatigue in the marathon MTB race, is a much lower, more aerobic power than in the road race. So not only is the storm to be weathered different in each race, but the “competitive finish” at the end is different. Looking at where the peak powers occurred in the road race, you see the absolute intensity for the 30s and 60s powers are the same, but come much later in the race. Again to try and make things simple (complex can be fun, but simple is productive) the road race gets more intense as the race gets closer to the finish, the MTB race gets less intense and more about diesel aerobic power. The higher the power, the more the effort relies on carbohydrate, simple trend. To the point, if we look at the final hour of the road race vs. the MTB race, the final hour of the road race is almost all power that is either above FTP, or coasting (descending). Whereas the MTB race has a lot less oscillation, a lot less high power effort in that final hour. The MTB athlete can be competitive, on quite different nutrition and ability to tap over threshold powers under fatigue.

So what is the takeaway? Well, I don’t know, two different races, two different detail sets, yeah that’s probably pretty expected. There are a lot of ways you could look at these different files, and ways you could call them similar or different. The big applicable point that I like to draw from them is that a good way to break down race demands may be to break them into two simple categories. The first demand and priority should be what is the general workload (i.e. duration, energy demand, TSS). The second demand and priority should be what is the composition of the general workload. This is where we really start to see the differences. It all feeds back into probably the most basic ideology of endurance sport training, that athletes should start with general preparation and move towards more specific preparation. Now that I have typed all these words and am reaching this conclusion, I am a little disappointed, not to bring something more interesting and controversial to the table. However, often the oldest and most practiced philosophies are the best and most secure. To leave it with a counter I would say that it is never too early in training to start incorporating specificity towards the task demands of an event. It is easy to go overboard with that, and lose some of the key general preparation, but in bits and pieces, why not train specifically for what you’re going to race?

The punch line? 5th in the road race, 1st in the marathon MTB race.