In Part 2 of Strength Training for Runners, we look at outputs, recruitment of muscle fibres and tendon elastic abilities.
In Strength Training for Runners Part 1, I explored how and why being stronger can help improve your running performance. Now we will look at the methods in which elite runners increase their force outputs, recruitment of muscle fibres and improve their tendons elastic abilities – using the calf and Achilles as the prime example.
Muscle strength and injury
Research has shown the link between making a muscle stronger and the decreased risk of subsequent injury – both to the muscle itself and the surrounding joints and connective tissues. If you don’t believe me check out some of these studies on calf size and strength on injury rates. As if that’s not enough reason to begin strength training, performance has also been shown to be enhanced following well structured and progressive strength training (Paavolainen et al., 1999).
Just as not everyone responds the same way to a running programme, people have different weaknesses, structural issues and injury histories. This means blanket statements about the best exercises can be irresponsible, as well as inaccurate. Knowing your weaknesses and limitations is the first step on the ladder towards designing an appropriate strength programme.
Improving performance with strength training
That said, distance running uses the whole body with the lower leg taking most of the impact. Arguably the ankle and calf are the first link in the chain to improving performance. The calf (primarily made up of the gastrocnemius and soleus) and Achilles tendon complex (known as a musculo-tenidnous unit or MTU) provide much of the propulsive force for slower paced running.
The muscles themselves ideally contract and stay the same length just before the foot hits the ground, while the tendon lengthens and shortens – storing and returning elastic energy. Obviously this happens over and over again as you run. Increasing the ability of the muscle to contract with minimal effort makes the process more efficient and wastes less of the elastic energy.
The tendon also must be resilient and strong and durable enough to handle these forces pulling from both ends – the bony attachment in the foot, and the muscles holding it taught at the top. A common cause of injury in long distance runners is the Achilles tendon being unable to sustain this force transfer. Like any other tissue in the body it requires progressively increasing load in order to adapt and to lay down more collagen fibres. This process takes around 36-48 hours meaning those who expose their Achilles to frequent stress and never let it recover and improve are at high risk of developing a painful tendinopathy. The major cause for concern is that it doesn’t start hurting until after the damage is done. The materials and pain receptors aren’t created and replaced until the tendon is already in a poor state of repair.
It’s not all doom and gloom!
Basic calf and ankle exercises can help prevent this occurring in the first place. Calf raises can be done on both feet, one leg, knee straight or knee bent, leaving plenty of variety and room for progression.
Plyometrics are exercises that use the stretch shortening cycle (SSC) as discussed earlier, and can focus on the ankle complex or the knee or hips or all three. Low level plyometric exercises are designed to introduce the emphasis of the ankle/calf SSC and teach the trainee to utilise the elastic energy instead of wasting energy by over using the muscles.
Stay tuned for short ‘how to’ clips of low level plyometrics and “Part 3” where I will discuss leg and trunk strength in improving running performance.
About the Author: Alex Adams BSc, ASCC, CSCS
Alex has worked in the fitness industry for over 10 years, his clients range from elite athletes to the general public. Currently based at PerformancePro London, Alex coaches Olympic weightlifting and strength and conditioning as well as presenting and tutoring on both subjects.
(Original article written for and posted on www.completeendurancerunning.com)