Restoring Load Capacity in the Injured Runner:
By Dane Verwey
Continuing on from last weeks blog about the importance of; ‘monitoring LOAD in training’, it made logical sense to make this blog about; ‘how to improve Load capacity and tolerance’. I learnt some important lessons about just how strong us runners ought to be, earlier this year.
On the 6th and 7th of July this year I attended ‘The Run Science Symposium’ at La Trobe University, Bundoora.
Below was one of the most revealing messages I gained from the weekend during a lecture conducted by the globally famous running researcher from the US; Dr Rich Willy.
We probably underload our runners in rehab, bodyweight exercises just don’t get it done!
Ok, so what does this mean?
Well, during stance phase in running this study by Dorn et al 2014 suggest just how much force is going through our legs. (Diagram adapted from Rich Willy lecture)
So, with every running step we have approximately up to 8 times bodyweight of force going through our calf, 6 going through our quadriceps and 3 going through our gluts! How many steps in a routine 5-10km run? That’s a whole heap of LOAD!
I am guilty of rehabbing so many running athletes for several years with largely body weight exercises and therabands. Not to say these exercises aren’t wrong for activating and firing up lazy muscles but they need to be expanded upon if we are being truly specific for the load demands of running. For years I had the thought that running is an endurance sport so if you can do 30 Single Leg body weight Calf Raises with good technique you have a pretty robust calf and Achilles complex! I now believe I was wrong! To build robust athletes we have to go above and beyond this.
Here is another important slide illustrating the above point (once again adapted from Dr Rich Willy’s presentation). Take your time to read this one.
As you can see above numerous studies have found that during running the achilles has about 4-8 times body weight of force going through it. While when we do unweighted single leg calf raises only 3 time body weight of force is going through the Achilles. So, once we have mastered 30 good single leg body weight calf raises, we need to add some external weight if we are really trying to specifically make the calf and achilles strong enough to cope and perform optimally again.
Now, I’m not advising you all go to the gym and add 7 times your body weight on your shoulders! All us distance runners would break! No, it is important to know the achilles applies its force to the heel bone several cms away from the central axis of the ankle joint, it is because of this ‘moment arm’ that simply adding roughly 5-15kgs is often enough.
How heavy should you start? Start at whatever load leads to a state of neuromuscular fatigue/failure at 10 repetitions. This is the ‘correct weight’.
The same message also applies to; single leg body weight squats. I’ve prescribed these to runners for years. Yes, they are great to start with and master technique but as you can see below (thanks Dr Rich Willy again!), a single leg body weight squat even with 70 degrees knee flexion (far in excess of the range used when running) does not challenge the quad or calf strength anywhere close to the demands required for running.
So once again, as with the calf we need to add external loads to our single leg squats. A goal for the single leg squat should be to be able to eventually lift a barbell (approximately ½ your body weight) on your shoulders (this means you are essentially squatting 1.5 time your bodyweight). Once again to start with if you fatigue at 10 reps with an unweighted barbell across your shoulders, master this first. Weight vest, weighted back packs and smiths machines can make this exercises easier as balance will obviously be a concern due to the single leg nature of it all.
Why always single leg? Well, that’s how we land in running, on one leg, so we better assimilate the loads required. As soon as we do double leg anything, the loads through our legs are halved.
So, fatigue at 10 reps is a strength illiciting doseage, how many sets?
Along with your calf work, you would proceed to do 3 sets of these single leg weighted squats.
How often? Twice a week with a good 48-72 hours between them to allow for recovery/regeneration and ensure you aren’t overloading.
When should you complete these heavy strength sessions? I generally recommend you do them on the same day and immediately after your interval/hard sessions of the week. I feel then you can just jog easy the next day and recover, rather than fill your recovery day with another straining stimulus.
Don’t get me wrong I am also a huge advocate of; pilates, control, balance and flexibility (if its an issue). Every runner differs in their needs. However, the beauty about what I have explained is it appeals to the masses.
Running gives our muscles good endurance but not the power or strength we can gain from weighted exercises. We need to remind our body to maintain muscle strength and power, as as we get older if we don’t, we invariably lose it naturally year to year.
As runners we all use our leg extensor muscles (calves, quads and gluts) just so much in running to absorb the shock going through our body. So, every single runner out there needs to maintain a strong and robust calf. Every runner needs to have a strong and robust quad. Every runner needs a strong and robust glut.
I feel having a diet of weighted single leg squats, leg press or calf raises should be in every runners routine. It is why I have blogged about it, I feel every runner should have a heavy dumbbell, sack of rice/sand, weighted school bag or if you are lucky a gym, to access and stay strong.
So, if you have a weak area that keeps breaking down, perhaps you aren’t going heavy enough? Maybe, the loads you have rehabilitated don’t match the strength and force that running demands?
So, the huge take home messages here:
If you are a keen runner who wants to continue to push your body well into the future, ensure your tissue tolerance stays high with the addition of weighted strength training twice a week. Not just body weight exercises, but weighted squats and calf raises! Remember running alone isn’t enough. Yes, interval training, hill work, plyo all help but nothing beats just sitting down and isolating a muscle and building its load tolerance with heavy strength training.
Another interesting side point is that a number of studies over the past decade have suggested that adding heavy strength training into your routine could potentially improve endurance performance by 1-4%!
Anyway guys a shorter one from me this week, as I better scurry along and do all the other jobs I had lined up for today! I hope it proves interesting and please if you have any questions let me know on the RunCulture instagram or facebook page. Or send me an email at firstname.lastname@example.org.
Hope you are all enjoying your running!