Are you a 'skilled' runner? Part 1
Alan Couzens, MS (Sports Science)
Dec 22nd, 2014
In a previous blog post, I asked the question, are you a skilled swimmer? I looked at this question by plotting actual pace swum vs VO2max for 3 levels of swimmer – 'skilled', 'triathlete' & 'unskilled'. We can make a similar comparison for the run by exploring the concept of running economy, i.e. how much O2 it 'costs' a given athlete to run a fixed distance.
There is a wide range here, for the bulk of runners, somewhere between 190 and 230 ml/kg/km, although some very elite runners have reported test values as high as 150ml/kg/km and, presumably, some very ‘non-elite’ runners have occupied a similar extreme at the other end. In my own experience in testing endurance athletes across the performance spectrum, I have seen a range of numbers from 187 to 235 ml/kg/km , with a mean of 211ml/kg/km and a standard deviation of ~9ml/kg/km (~5.9%). This is almost double the standard deviation that I have seen in cycling economy numbers (3.1%), suggesting that there are more factors at play when it comes to the run. For this reason, I place the run in the middle of the fitness<->skill spectrum, with cycling to the left of it, being a more fitness determined discipline, and swimming to the right, having a large skill component.Studies that have looked at the key determinants of running economy would tend to support this view, showing a mix of physiological and kinematic/technical factors that impact the oxygen cost for a given pace. The most consistent ‘major players’ being…
- Muscle fiber composition (Bosco et al., 1987; Kaneko, 1990)
- Thermoregulation (Brooks et al., 1971; McDougall et al., 1974)
- Gender (Daniels and Daniels, 1992)
- Anthropometry (overall body mass & limb lengths/weights) (Williams & Cavanaugh, 1987)
- Durability (Braun & Dutto, 2003)
- Kinematic Factors/Running ‘Skill’
Indeed, I would suggest that a large portion of the gap in variance between cycling and running economy comes down to the addition of that last factor. At the risk of generalization, with a bit of practice, anyone can ride a bike relatively efficiently but, as a trip to the local park can confirm, efficiency in running is the exception rather than the norm!
Which brings us to the critical question: Are you a skilled runner?
We can go a ways toward answering that question by looking at that key metric, running economy. How do you stack up? If you have recent lab data from a VO2max test, you can compare yourself directly to the numbers that I've given already by entering them below...
|Speed at VO2max (km/h)|
Running Economy: ml/kg/km
Of course, you can (& probably should) also enter submaximal VO2 levels and your corresponding speed during the test to get a better perspective of overall run economy and an idea of your economy at paces specific to your event
However, even if you don’t have recent lab measures, given the relatively smaller range of cycling economy vs running economy, you can also get a feel for your running ‘skill level’ by comparing your bike and run numbers from current field data in a similar comparison to that made in the 'skilled swimmer' article…
Estimated Running Economy: ml/kg/km
To put the impact of running skill into a 'real world' performance context, let's take a look at 3 different economy levels ('skilled','triathlete','novice') for a given athlete (bodyweight = 75kg), expressed across the race duration spectrum.
If we take a look at the tables above, it is clear that, even within the typical ranges of run economy of 190-230 ml/kg/km, the actual impact on race times, especially over longer events, like the Ironman marathon, is considerable. For your typical athlete in “Kona shape”, the difference between an athlete with “skilled” economy numbers vs “unskilled” economy numbers could amount to 40 minutes or more over the race course!
Put another way, even small improvements in running economy are likely to have a large impact on race performance for those athletes who specialize in longer events!
While some of these factors that impact economy are outside of the athletes control (e.g. limb length), the skill related factors are not. I will explore some of these crucial kinematic factors along with the most scientifically validated training methods to improve them in my next article. Until then…
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