Pace Variation: The Missing Link in Running Injury and Performance

Slow and Slower

Relative to a maximum sprint, runners spend the majority of their time running slow or variations of slow to moderate. The long run is slow. The recovery run is slow. Even the tempo run, if we compare it to the sprint is slow. If you’re not engaged in any interval work or only long intervals – the majority of your training load is slow.

You might not feel like it’s slow, for example, the effort on threshold runs and long runs differ considerably. This is why we must differentiate physiology from mechanics. Great variations in physiology can be produced from what are still relatively slow mechanics.


Look at the sprinter and the long-distance runner and contrast their mechanics. The sprinter has a pronounced bending of the hip, knee and ankle. The explosive nature of their sport means they use their legs through a full range of motion and with great force, one of the reasons we can easily see their well-developed muscles and tendons. By contrast, the long-distance runner tends to have a more subtle, slow stride that does not require the same obvious range of muscular work.

Physiological and Mechanical Overlap

In recent blogs, I discussed the training involved in attempting a sub-33 minute 10-km. I noticed some changes in my pain-soreness at different points in the programme that seemed to occur in tandem with changes in how I was feeling physiologically (perceived effort, tiredness etc.). I noticed the same phenomena occurring during ad-hoc training over the Christmas period. These experiences are the inspiration for this blog.

During the initial 9-weeks of 10-km training, I became very fit. By the end, I could perform 8-km (75 – 80 sec lap pace) track sessions very well. I could do a 5-km park run, 8 hills and 3-km in 10:10. During most of this phase with the exception of some tiredness, fitness was generally improving and pain-soreness was generally low. However, there came a point where I almost felt I’d stopped responding to the training. Like I could do most of the work comfortably but not really go any faster. A feeling of becoming one-paced. Interestingly, this one-paced feeling was accompanied by an increase in pain-soreness.

Introducing a Stimulus Package

I began to add some efforts into the middle of runs like 15 x 60-secs on, 60-secs off or 2 sets of 10 x 30-secs on 30-secs off. Immediately, I felt better both physiologically (perceived effort, tiredness) and mechanically (pain-soreness). It got me thinking more about the overlap between ‘sprinter’ mechanics and distance runner musculoskeletal health and fitness.

Over Christmas, I noticed a similar pattern. The first week of the holidays, I mainly did runs of 8-miles in duration with similar short efforts included in the middle. I followed that with a 16:40 park run just before Christmas eve. I then decided I would just do some easy running with a friend for a few days (often the runner’s default during off-seasons). Almost immediately, when using the slow mechanics for similar duration, I began to notice pain and soreness creeping back in. Invariably, the re-introduction of some higher paced efforts in the new year (e.g. 12 x 400m in 75-secs) has settled the soreness.

So What?

I’ve come to see the benefit of pace variation during standard runs for fitness maintenance and pain management. For example, I ran 16:26 in a New Years day park run having used an unstructured programme for at least a month. I find it kills the monotony of constant easy running but at the same time it does not require the same mental effort as a full-on interval session.

Unsurprisingly and not for the first time on this blog, I think – the plodding is the distance runners biggest enemy. These concepts will be particularly important for my marathon programme where the volume of slow running heightens the risk of stagnant physiology and musculoskeletal tissues. This combined with some barefoot running (better mechanics during slow running) and conditioning should be a big help.

The Next Blog

The Flexible Mindset: Key to the Design of the Consistent Run Programme. This blog will kick-start the journey to my first marathon which will hopefully be Limerick, May 2019. It had to be Limerick for my debut, click here to read why. Due to requests for more information on how I design my training programmes, the blog will largely outline my marathon plan. Until next time, happy new year. Peter.