Hi, I am Enda, Senior Physiotherapist and Clinical Lead of Running Solutions at Premier Physiotherapy.

Introduction

Most runners present to a physiotherapy appointment due to injury. And the majority of running-related injuries are non-traumatic overuse injuries. While the causes of these are multifactorial, a common theme is a lack of strength of the muscles in the affected area, relative to the persons’ body weight. Logic, as well as indisputable robust research (Beattie et al, 2017), therefore dictates that runners should perform regular strength training to reduce the risk of injuries occurring in the first place. A common pushback to strength training that I hear in the clinic is that “my legs are strong enough from running, I don’t need to strength train”. I can understand this thinking, but on the other hand, runners are exposing themselves to increased injury risk, as well as leaving performance benefits on the table, if they are not performing regular and appropriate strength training.

Why Running Doesn’t Increase Strength

There are two key reasons why running alone does NOT increase the strength and capacity of muscles, bones and tendons. The first is that when running, these tissues are exposed to extremely high loads and forces. The calf muscles for example, must produce 6-8 times of our bodyweight with every stride! This means that every run will overload our tissues with more force than they can deal with, unless they are conditioned to be fitter and stronger.

You could argue that the exposure to these forces while running will do this. However, that is where the second factor, known as the ‘interference effect’, comes in. In simple terms, this means that our bone and tendon cells ‘switch off’ after about one hundred footstrikes (Warden et al, 2021). After that point, nothing is being strengthened. In fact, the forces on these tissues caused by running are breaking them down. If the rate of this breakdown exceeds the post-run recovery you provide, an overuse injury is likely to follow suit.

The Importance of Strength Training

The aim of this article is to highlight that running alone does not build muscles and bones, and that strength training is MORE important for runners than the average population. There will be follow up posts with recommendations on how to structure strength training to compliment your running training, and get the most bang for your buck from lifting weights. For now, it is enough to know that strength training for runners is a necessity, not a luxury!

Happy Running!!

Enda specialises in treating running-related injuries, as well as providing training plans and strength and conditioning advice for runners. An experienced runner himself, Enda has completed multiple marathons, including completing the London 2024 marathon, with a PB of 2:46:11 and completed his first Ironman in under 11 hours in June 2024.