Methods for incorporating cross-training as part of an ultra marathon training plan for injury prevention

The Principle of Specificity (SAID) is well-known in endurance sport, and states that the human body adapts in a specific way to the particular demands placed upon it. As it relates to ultrarunning, the SAID principle is taken to imply: the more running, the better.  But the prevalence of injury, particularly in trail and ultrarunners, may overshadow the benefits of running specificity. Research has shown benefits to cross-training, not only with regards to injury prevention, but possible increases in athletic performance as well. 

This blog takes a closer look at the role cross training can play in training plan design for ultrarunners, giving examples of application and integration in training plans to support injury-prevention goals, consider past injuries, or simply giving the athlete other training options. The thesis is that when implemented appropriately, cross-training can support and supplement the ultra training cycle in a way that does not lead to performance decreases on race day.

Prevalence of Injury in Ultrarunners 

Join any group trail run, forum post or online ultrarunning community and you’re likely to hear or read somebody’s story about a recent injury: whether it be an ankle roll, tendinopathy, lower back pain, or any number of complaints. Research is emerging with startling data on the prevalence of injury among ultrarunners. In one study [3], ultrarunner respondents had at least one running injury reported by 90% of participants, an astounding number. Another study [1], [2] cited that twenty two percent (22%) of race participants across four unique events had suffered ITB syndrome, ten percent (10%) had an Achilles tendon injury, nine percent (9%) had hamstring injuries, and seven percent (7%) had calf muscle injury over the last 12 months, with an additional nineteen percent (19%) reporting chronic injuries to the knee and lower leg. The question is: how can the coaching community do more to support safe training for these athletes? 

Cross-Training for Injury Prevention and Performance

Well-known ultrarunners such as Kilian Jornet, David Roche, and Heather Jackson are known for integrating cross-training in their training cycles, including biking, skiing, swimming, and more. Even in peak training cycles, David Roche, who set a new course record at the Leadville 100 in 2025 includes bike workout sessions once a week. When looking at studies of amateurs  [4], a number of datapoints suggest that not only does cross-training maintain fitness, but could actually improve it. 

In 2018, a study [6] looked at the impact of cross-training for injury prevention. In the study, runners replaced two days of easy running with cross training sessions in one of three categories: elliptical, bike or an elliptical-bike. All three resulted in increased half-mile performance. Further, a 2004 study [7] found that the stairclimber, the elliptical, and running all resulted in similar improvements where training volume and intensity were the same. Coach Trent Sgellingwerff, who coaches Canadian world-record holder Natasha Wodak said that Wodak “uses the elliptical 2 to 4 times/week proactively to add aerobic volume more safely,” resulting in 2 hours of extra aerobic load.

It’s becoming more and more common to see professional athletes employ cross-training, either for injury prevention or performance-enhancing considerations. The following section details how exactly to add cross-training to a plan for the desired result. 

How to Integrate Cross-Training: Leveraging Equivalent Workload

Many coaches are familiar with a version of the phrase: ‘the body doesn’t know miles, it only knows stress’. Another way of saying this is, ‘the body doesn’t know miles, it knows the workload it is under’. Exercise scientists refer to the combination of volume and intensity in training as ‘workload’. While more complicated methods of calculating workload, such as the Training Impulse can be used, simpler forms also exist using Rate of Perceived Exertion (RPE) alone, where the athlete records the duration of the activity in minutes and multiplies it by their RPE. Let’s look at a few examples of how this might be used:

Imagine an athlete would like to replace one easy training run each week with a cross-training session for injury-prevention purposes. This run is usually 1 hour (60 minutes) in duration at an RPE of 3, which has a workload of 60 x 3 = 180. We could give the athlete an option to replace this run with a 60 minute elliptical session at an REP of 3, or a bike ride with RPE of 2 for 90 minutes (180/2 = 90). 

Let's say another runner is unable to do frequent hilly runs due to achilles injury history. They would like to replace one of their trail runs (with climbs) with an equivalent low-impact workout at the gym. Here we consider not only the equivalent workload as above, but also the specificity required by the session to produce the training effect of climbing. There are a few options for this, and much depends on the activities the athlete can tolerate, but the stairmaster might be an excellent choice. Doing a hill workout on a bike might be another option, or a treadmill hike. 

The same science applies on the upper end as well. Let’s say an athlete is unable to do speed work sessions due to injury history but they’d like to try a speed block to set a PR at an upcoming 50 miler. Let’s say the prescribed workout was 2x20 minutes tempo at an RPE of 8/10 with warm up and cool down. The workout portion alone (to keep things simple) is a workload of 40 minutes x 8 = 320. The same workout could easily be replicated on the elliptical for an equivalent aerobic stimulus, same goes for VO2 workouts. Perhaps this claim evokes rage with the purists, that you are, in fact, lacking the specific mechanical stress: but particularly for an ultrarunner who is likely just looking for help running up that 2 mile hill at mile 47 of their 50 miler, is the mechanical stress of the sprint important? Especially for an amateur that might just be looking for PB, not looking to set a new Leadville course record. And there are still real-world examples of pros using the elliptical: Parker Valby, for example, who finished 2nd at the NCAA 5k championships only running 2 days/week, and credits her success to her cross-training regimen [5] or further examples in this article.  

With a simple calculation, cross-training can be added to any ultra plan, whether it be a safer way to do speed work, supplement climbing, adding volume safely, or just giving a runner something different to do one day of the week.

Open Questions, Conclusions

There are nuances to consider with different mechanical stressors to the muscles during cross training activities which are more challenging to quantify. What is the limit of cross-training for ultrarunners? More research is required. However, data suggests that assuming the runner is capable of doing the majority of their training as-planned there is no negative impact to cross-training. To the contrary, it’s possible that cross-training is a safer way to add volume to a plan for an athlete that is newer to the sport, and may positively impact performance. Interested in adding cross-training to your runners plan or want more ideas? Please don’t hesitate to get in touch!