Transferring Road Fitness to Trail Fitness

There’s a principle that is referred to regularly in the strength and conditioning landscape known as the SAID principle. Specific Adaptation to Imposed Demands, the concept posits that training needs to be specific for what you want to achieve and the demands that are placed on the structure. While specificity is important, there is a transferral of training and previous adaptations that is applicable albeit non-specific. For example, long distance run training for a road race is not specific for trail racing, however the training benefits that arise from running will still apply across both disciplines.

Last weekend I took my first plunge into trail racing. Coming back from an injury, I approached the weekend feeling as if I hadn’t pushed my training to the limits that I wanted, constrained by the need to reduce loads and volume over the weeks leading in. I had put in some effort on uphill climbs, worked through some longer runs with increased elevation and took advantage of every downhill as best I could. But I love to run fast, and given the opportunity to do a speed workout or hill workout, the former wins out more often than the latter. I stood on the start line slightly nervous that the uphill was going to destroy my legs and the downhill would be a lost cause, leaving me little opportunity to put my running to work. The reality ended up different. My strong aerobic base and years of volume in my legs meant I could quite efficiently climb the hills through running and fast hiking. When it came to flatter sections or kind downhills, I still had lots left in my legs to run some of my fastest kilometers. Where I fell apart was on steep technical descents over rocky terrain and uneven surfaces. I didn’t train for this specificity, and it showed.

The point of this is that there will always be a specific component of a fitness endeavour that requires targeted training. But it doesn’t mean you have to throw out everything you have already been doing that your body knows. Instead, use what you have and where you are starting from, and then build in the missing pieces to account for your deficits. If you want to apply this across road and trail running, going between the two, here are some things to think about:

1. Volume matters

   Because running trails takes longer, it can be easy to sacrifice volume. While there is a place for running based on time and not distance, starting with a base that has had some higher volume means that your legs will be conditioned to covering distance and you can focus more on training them for climbing and descending. It becomes more challenging to build up volume, speed and climbing tolerance simultaneously, as you often trade off one for the other. Likewise, evidence exists to inform us that rapid increases in volume, or single training session spikes increase injury risk more than a gradual build. This is especially relevant in working towards a goal race where run distance will need to increase in preparation (3, 4).

2. Consider muscular endurance

   Once you build an aerobic base that can carry you for long distances, it is no longer likely to be the limiting factor for tackling trails. Rather than being cardiovascular conditioning that holds you back, it is muscular fatigue. To build the capacity for your muscles to perform for longer at the required outputs (i.e. at faster paces or on steep inclines and declines) simply running on flat ground or going and doing a few hills won’t be enough. Instead, tackle hill repeats of long hills and high reps (i.e. 10-12 of 500m-1km long hills), pushing pace as much as possible on the way up, and on the way down. Once this is possible, change a variable: add weight using a weighted vest, do more repeats or find a bigger hill! Any of these options that challenge your legs in condition-specific circumstances will allow for adaptation that will apply when it comes to the trails (1).

3. Downhills are different

   Running downhill requires a different type of muscular engagement in your quads compared to uphill or flat. Known as eccentric, it is when your muscles are lengthening under load. In the case of the quads, they are in a lengthened position as you take your step going downhill, but have to act as the braking force for you going down. With inadequate training for them to manage this type of loading, they’ll get sore quite quickly (and object to any further descending!). While running downhill sounds like the fun part, and cardiovascularly may be easier, from a musculoskeletal system perspective, it requires some targeted training (2).

4. Train the demand

   This is the main area where I went wrong. While I did lots of downhill running to condition my quads and lots of uphill running to build endurance, I didn’t do enough on technical terrain that truly demanded of me what the course and event asked for. When it came to having to keep pace on challenging downhills, I lost a lot of time. Look at the event you are doing and figure out what it asks - train those domains, while maintaining the principles of good running, including nutrition, base volume, easy runs and some speed work.

Running offers a challenging, rewarding and multi-system benefit to the brain and body. In some ways, it is simple - running is running. But beneath the top layer, and with a bigger goal at hand, it requires a more in-depth breakdown of its components and some focused attention on bridging the gap from where you are to where you want to be.

References

(1) Muscular Endurance from Scott Johnson
(2) A review of uphill and downhill running: Biomechanics, physiology and modulating factors
(3) How much running is too much?
(4) The association between weekly running distance and running related injury