Maintain Running Cadence Under Fatigue on Race Day
There are so many sources out there providing the standard technique advice of increasing running cadence (stride frequency) to help stop athletes from over striding, and amongst other things helping to increase in limb stiffness.
Many of these sources suggest 180 strides per minute as being a good rule of thumb for 'optimal cadence'...
However, in reality optimal running cadence will vary from person to person, and improtantly from pace to pace within one individual athlete. As with anything else running form related, there is no 'one size fits all' solution.
More thoughts on running cadence as a variable factor here:
- Running Cadence - Recent Research - (Dec 2011)
- Improving Your Running Cadence Range - (May 2012)
The 5-10% Cadence Rule
Many of the runners I see experimenting with cadence indeed do so in an effort to stop over striding... and rightly so!
Commonly one of the biggest sources of frustration they cite however, is that the increased cadence they've been working to achieve is perhaps too far increased from their habitual cadence for a given pace, and thus unsustainable / uncomfortable.
Example:
A typical example would be a runner with a marathon race pace of 5:00 min/km, who runs at this pace with a habitual cadence of 160 strides per minute (spm). Suddenly asking the athlete to run at 180spm is a significant increase! Sure, stride length will decrease if they keep the same pace and increase cadence. It has to! But how long will the athlete be able to maintain running with this quicker rate of turn-over before cadence slows with fatigue as longer runs progress in duration?
Given how we know that a cadence increase of just 5-10% for a given pace results in positive changes in loading at the knee and hip (more here), a more achievable and importantly sustainable 5-10% increase of cadence to 168-176spm will be enough for the athlete in our example to improve running form for the better.
More importantly this 5-10% change in cadence will be far easier for the athlete to maintain later into longer runs, and the marathon itself.
In distance runners, ironman triathletes, ultra runners etc... I consistently see great results in getting athletes comfortable with a cadence increased to the point where it achieves the desired outcome (increased limb stiffness, reduced over stride, shorter contact time) yet is also sustainable, using the 5-10% rule. We then use digital metronomes to develop the athlete's ability to maintain this increased cadence into fatigue during longer runs in training.
Cadence & Training Specificity
Regardless of event or distance, we should always be trying to deliver a certain element of race specificity into our training. For endurance athletes this means preparing the body in training for the rigours of competition over long distances, training it to endure local muscle and systemic fatigue.
As anybody who has run a marathon will tell you, running form changes with fatigue! One of the first elements to slip is usually cadence - the legs slow down! At this point your body has two choices, run slower or begin to over stride as you fight to maintain the same pace with a slower cadence...
This characteristic of cadence slowing under fatigue is something we can successfully improve with some simple strategies in training. Simply put, the goal is to teach the body to maintain cadence (think 'leg speed') as fatigue hits.
The graph below (via @RussMCox) provides a great visual of how on like-for-like training runs, the only change being the use of a digital metronome to maintain cadence, consistency can be developed and the body trained to maintain a given cadence for longer.
From Russ' Accompanying Blog Post:
I ran the same thirty minute route on Tuesday and Thursday this week, the first unaccompanied and the second with metronome. As the graph shows they both occupy a narrow cadence range, but the difference is consistency – with the metronome everything is a little more crisp and controlled; the beat guides me. To further this anecdotal evidence I will note that while I was fresher on Tuesday it was then my cadence fell towards the end of the run. Fatigue would predict Thursday to be the day I struggled, but the bleeps kept me honest....
Try For Yourself
You can easily try this at home. On your next long run, try taking a digital metronome with you set to the desired cadence. Once you feel your legs getting tired, turn it on and try to match your cadence to the beat, while running at the desired long run pace.
Learning to maintain cadence under fatigue is a great way to teach your body to maintain good form under duress.
For those who run with music, try putting together a playlist of songs at a given BPM, for when the legs tire. Here's a free resource that will help with some inspiration when playing DJ!