New Levels Coach Matt Long introduces you to the concept of the differentially based session.
I recently took a group of talented athletes onto a track and took them through their RAMP warm up. “What’s the session you’ve got for us today?” one eagerly asked as he unzipped his tracksuit top. “Its 4 efforts of 4 minutes in duration,” I replied before adding that they’d get a 2 minute jog recovery. “Sounds easy enough”, I heard one of them mutter under her breath. I stifled a smile to myself as I had deliberately withheld a key word which was about to radically alter their perception of the ‘easiness’ of the session. Unable to contain myself any further I said, “There’s a sting in the tail to this session. It has what we call a ‘differential’ element”. I noticed changes in facial expression amongst the group very quickly!
The session which I was alluding to was underpinned by the work of the late national coach and coach mentor David Sunderland who penned High Performance Middle Distance Running two decades ago in 2006. In disaggregating the notion of ‘speed endurance’ Sunderland alluded to a variety of modes of session which involved changing pace within a single repetition. Some of these included (a) a classic differential – which is a two paced change within one rep;
(b) a pace progressor– which is a three paced change within one rep;
(c) a pace injector- which involves a faster middle component within one rep and
(d) a tired surge– which involves a ‘float’ (slightly faster than a jog) element in the middle.
The specifics of the session which I delivered were as follows:
4 x 4 mins off 2 mins jog recovery.
Rep 1. Differential. 2 mins @ 8 out of 10 RPE/ 2 mins @ 9 out of 10 RPE
Rep 2. Pace progressor. 2 mins @ 8 out of 10 RPE/ 60 secs @ 9 out of 10 RPE/ 60s @ 10 out of 10 RPE
Rep 3. Pace injector. 90s @ 7 out of 10 RPE/ 60s @ 10 out of 10 RPE/ 90s @ 7 out of 10 RPE
Rep 4. Tired surge. 90s @ 9 out of 10 RPE/ 60s float (slightly faster than jog)/ 90s @ 9 out of 10 RPE
During our cooldown I was rightly challenged by an athlete. “Blimey that was tough”, she said, “But I don’t see the point of it. When I’m racing a 5k, 10k or marathon for that matter I want to be running even paced splits not changing pace all over the place!”. Of course in many ways she is right.
As our founder Lewis Moses often reminds us on his brilliant podcasts, running an even paced or slightly negative split is indeed the best way for many of us to approach the undertaking of any endurance race. So why the inclusion of what we have framed as a ‘differential’ session?
What the athletes found was that a cumulative volume of 22 minutes running (including of course 6 mins active recovery) was much harder than a simple 4 x 4 mins at one even pace. A useful analogy would be my own daily commute from the brewery town of Burton on Trent to my place of work and coaching at Loughborough University. A relatively traffic free day means I can drive in 3rd and 4th gears most of the way and conserve petrol. If I commence my journey in rush hour however I’m going to hit traffic and I will use more petrol as I inevitably move between gears from stationary stops on the A38 back up through 2nd, 3rd and 4th gears and frustratingly back down again as the congestion ebbs and flows. So the tired athletes I was speaking to had found that in effect they had used more ‘petrol’ as they moved up and down their gears on the track.
If you look at the specifics of the session I had set above, you will see that rather than working the athletes at a singular pace, I was working athletes at not two, three, even four but five differential paces- namely 7, 8, 9 and 10 RPE plus a ‘float’ recovery. This means that the training effect from the session is likely to be greater in terms of the physiological adaptations which take place.
Let’s take just one of the reps- namely the ‘pace injector’ (Rep no. 3). When moving from 7 out of 10 RPE up to 10 out of 10 for a short while and then back down again to a 7 out of 10, the latter part of the rep requires the athlete to clear the waste product of acid from their system whilst still trying to operate at a pace close to threshold after running flat out. The physiology underpinning this process can be traced back to the mid 1980s and the work of Dr G.A. Brooks and his notion of the ‘lactate shuttle’ in the context of metabolic energy production.
In addition by including differentially based sessions which move us up and down the proverbial ‘gears’ we are habituating pace judgement by listening to the intrinsic feedback of our bodies. So these modes of differentially based sessions have psychological as well as physiological benefits.
One of the ‘drawbacks’ of the session which athletes sometimes report is that inevitably they are not able to cover as much distance as they ordinarily would in a session run at one singular pace. This is true and can be a problem for the coach in a Strava driven culture where stats and the optics of performance even in training appear paramount. So the way to navigate this which was inherent in my session was to run athletes to time rather than set distance (i.e 4 mins rather than 1km) and feel rather than split (i.e RPE).
Of course sometimes it may be appropriate to ‘sandwich’ the differentially paced reps in the middle of reps which are run at even pace. If we had wanted to add more volume to the session articulated above we could have gone for 6 x 4 mins for example, with Reps 1 and 6 being run at even pace with the middle four reps being undertaken with a differentially based element. This covers all bases so to speak.
The above leaves us with the following questions for self-reflection….
- Does my current training schedule include any kind of differential paced running sessions e.g. A progression run where paces get incrementally faster every km or every few mins? This is important to ‘bridge’ up to a more formal session of the kind described above.
- What scope is there to more formally introduce a differentially paced session in my periodised plan of training?
- How might differentially based sessions help my long-term athlete development both in terms of physiology and pace judgement?
Matt Long is a New Levels coach who has team staffed for England internationally for the last 4 years. He has guided two athletes to become world champions in his career.
