Long vs short trail races - what determines performance?
The end of the racing season offers the potential to mix something fun into the winter training cycle. For me, this meant that I would sign up to a few shorter trail races in place of my usual weekly speed/tempo session. I hoped the excitement of racing and mingling with the trail running community would add variety and help me through the lull of winter.
However, this made me wonder - what do we know about the physiological factors that influence performance in short trail races and how do these differ from those things I am focusing on for ultra trail racing?
Why ask the question?
I thought it could help predict my performance in running shorter trail races off the back of training for ultra trail races. It would also help educate me on how to focus my own and my clients training for both of these modalities of trail racing. And finally, it gave me an excuse to peruse science journals to find other interesting stuff. Did you know that there is no evidence that sex effects sports performance? (Stefani et al, 2016). All those nights of celibacy before events for nothing!
The short stuff
Alvero-Cruz et al. (2016) demonstrated that the differences in percentage body fat and vVO2max between competitors during a 27km trail race could account for 83% of the variation in race time.
Err, what?! Lets break that down
Percentage body fat
What is it? How much of your body is made up with fat
How can we measure it?
1) Specific weighting scales send an electrical impulse through the body and the degree of resistance offered by the bones/fat/muscle can be used to determine body fat percentage. These can be unreliable as they are impacted by your hydration status and when you last ate.
2) Calculators online that use body measurements e.g. neck and abdominal circumference, for an estimate. The error here arises from the reproducibility of measurements over time
3) The researchers here used body callipers to measure skin folds. They plugged these into a complicated equation to estimate body fat percentage. It depends on whether calipers are ‘your kinda thing’!
I don’t see myself regularly getting a tape measure out and wrapping it around my neck and tummy. It all just sounds a bit far fetched. You’ve got to ask yourself ‘how is this going to change my training/lifestyle?’. I think the only accessible measure here that I might look to try out is the weighing scales. I think if you can learn to use them at the same time of day e.g. in the morning, and not pay attention to slight fluctuations but instead look at the overall trend, then perhaps you can see if you’re moving in the right direction.
Trainability
This comes down to the balance between calories burned vs calories ingested. If we put our body in a calorie deficit i.e. more out than in, it will largely burn body fat to bridge the gap.
The intensity we run at is also important - fat burning is at its optimum when running at about 65% of VO2max, or between zones 1 and 2 for most people. That means our easy days are really helping shift the extra weight, particularly important this time of year! Then it’s down to how long we spend in this zone, or our overall training volume. Increase this while maintaining a healthy diet and hey presto, you’ll be a lean, mean racing machine!
vVO2max
What is it?
‘v’ - The velocity you are moving at your VO2max. This takes into account your VO2max and your running economy, the latter being a measure of how efficient your body is at using energy.
‘VO2max’ - The maximum volume of oxygen your body can consume in a minute. This takes into account many factors including your lung capacity and its oxygen exchange system, blood volume and haemoglobin content, muscle volume and metabolic capacity.
In other words, vVO2max is a measure of how much energy your body can use and how efficiently you can use it.
Trainability
Your not alone if you’re struggling to wrap your head around this metric. Thats because it incorporates a lot of other values. The good news? This means there’s a lot for us to target to improve performance.
1.Running economy
We need to teach the body good form and then train it to hold that for the duration of our target race. Although we are all built to run, like any skill, running is something we have to learn to do well.
Suggestions:
Slowly incorporate strides and/or hill repeats into one of your easy runs each week. Start with 4x10sec and build up to 6x30sec over the course of 6-8weeks. These have strength and neuromuscular benefits
Introduce a plyometric routine including jumping squats, hopping, skipping, height skips and water hops (I’’ leave you google these for visual representations). These develop leg strength and teach the body to reduce ground contact time
Threshold intervals: 6-8 x3min at your 10k race pace (or RPE 8/10) with a 2min jog recovery between reps
2. VO2max
Training our bodies to utilise aerobic metabolism at higher effort levels will ultimately lead to us running faster for longer. VO2max is a highly trainable metric in the general public. However, as an athlete reaches the peak of their game, their VO2max plateaus and performance improvements are made elsewhere.
Suggestions - the beauty here is that it overlaps with those above giving us a ‘two birds, one stone’ scenario
8-10x400m at 1mile-3km race pace with 60-90sec jog recovery
Fartlek: 1, 2, 3, 4, 3, 2, 1min intervals moving from 1mile to 5km race pace and back with equal jog recoveries
The long stuff
Coates et al. (2020) looked at a number of potential performance indicators for athletes completing a 50km, 80km and 100mile ultramarathon. They found that the longer the event, the less predictable performance was. At the 50km and 80km distance, vVO2max was the best marker of performance. At the 100mile distance, no parameter accurately predicted results.
What does this mean?
The longer we go, the more blurry the picture gets. There is no one single parameter that, when trained, will mean we’ll complete the course faster. This is because more variables are introduced such as nutrition, mental strength, experience and terrain.
What do I take away from this?
Training for an ultramarathon is different to that of shorter trail races. There is no test you can perform to determine performance. You need to be prepared in a more diverse manner. For this reason, I like to make training as race specific as possible. Here’s a few ideas to get you thinking:
Start introducing and experimenting with your nutrition strategy early in the training cycle. What works for someone else won’t necessarily work for you. Camille Heron’s signature beer should come with a ‘don’t try this at home, folks’ warning!
Train on terrain similar to your upcoming race. Gradually introduce it so by the time you are in the lead up to the race, you are training on nothing but terrain mimicking the race. Lets take my current situation - I’m racing 50miles on the SWCP in January but I’m transition from a flat training cycle. Rather than suddenly change from flat tarmac to gnarly trails, start introducing it into one or two runs and slowly build that up. The same goes for elevation, don’t go from 200m to 2,000m per week. Allow your body time to adapt
Make a race plan. Even if you have no intention on actually using it. It forces your brain to start some basic mental imagery i.e. imagining yourself running the course, how you’ll be moving and feeling through different stages of the race, where your crew will be etc. This is much more effective if you are familiar with the race course
Build consistency and enjoyment into your running. If there is one thing I have learned it is not to arrive at the start line burnt out and exhausted. You need to be excited to run. Find what is motivating you and tattoo it onto your arm! This is what will power you through at the eleventh hour when your body is demanding rest and you’ve run out of Haribo!
Final thoughts
When I first got into exercise I dabbled in triathlon. I saw the transition leg as a blemish on a sport that was otherwise really attractive. After a few goes at competing, I realised this ‘fourth discipline’ was actually one of the more excited factors of the sport. Why the shift in mentality? Before giving it a go I didn’t understand the demands of it and what made it challenging. Like triathlon, ultramarathoning comes with a whole list of other challenges. They are not necessarily written on the box. Only by experiencing them do we come to understand how great these are. Perhaps this is why so many people who complete an ultramarathon become ‘serial offenders’!
References
Stefani. L, Galanti. G, Padulo. J, Bragazzi. N and Maffulli. N (2016). Sexual Activity before Sports Competition: A Systematic Review. Frontiers in Physiology. 7:246
Alvero-Cruz, J. R, Parent, M. V, Garcia, R. J, Carrillo de Albornoz-Gil, M, Benítez-Porres, J, Ordoñez, F. J, Rosemann, T, Nikolaidis, P. T and Knechtle, B (2019). Prediction of Performance in a Short Trail Running Race: The Role of Body Composition. Frontiers in Physiology. 10:1306
Coates, A. M, Berard, J. A, King, T. J and Burr, J. F. (2021). Physiological Determinants of Ultramarathon Trail-Running Performance. Int J Sports Physiol Perform. 10:1-8.
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