As marathon and fun run season approaches, so does the likelihood of sustaining a running-related injury. So why run? Why run if its going to leave you hot, sweaty and possibly injured?! The health benefits of running have been well documented for decades. Recreational running has been shown to increase life expectancy and reduce the risk of over 35 chronic conditions (Booth 2012), including cardiovascular disease, respiratory disease, dementia and many types of cancer.
But what about your knees? Doesn’t running cause arthritis? Not exactly. The risk of developing knee and hip osteoarthritis in a non-runner is 10.2% compared to a competitive runners who has a 13.3% chance. However, recreational runners have only a 3.5% risk of developing arthritis (Alentorn-Geli, et al. 2017). This means that running regularly, 2-3 times per week, more than halves your risk of developing osteoarthritis!
So how do you get all the health benefits of running, but reduce the risk of the aches, pains and injuries that often go with it? Here are five key things I discuss with my clients to get them running stronger, longer and safer.
Cadence, otherwise know as step-rate, is the numbers of steps taken in one minute of running.
The “optimal” cadence is reported to be 180 steps per minute. Classically, new or novice runners will present with a slow cadence ie. a low step rate of around 150-160 spm. Increasing step rate towards a more optimal cadence reduces the amount of ground reaction forces with each stride and improves many other biomechanics factors of running, thereby reducing stress on the joints and muscles and improving performance.
To find out what your cadence is, simply count how many steps you take in ten seconds, then multiply this number by six, to get your steps per minute. Other tools that can be useful are running with a metronome in your head phones, which can be downloaded to your smart phone. This can be a bit dull, and many clients report that it takes the fun out of running. An alternative is to download a 180bpm playlist from Spotify, ITunes or other music streaming ap.
Over-stride relates to where your foot lands (initial contact) relative to your centre of mass. In other words, if you drew a vertical line down from the centre of your pelvis, how far in front does your foot land at impact.
Initial contact should occur approximately two-thirds of a foot in front of your centre of mass. More than this distance is termed over – stride. The further in front the foot is at impact, the more those ground reaction forces are coming back at you, thereby slowing you down and increasing joint stresses higher up. Injury-risk aside, the best thing about reducing your overstrike is actually how much faster and easier you can run.
Cadence and over-stride often go hand-in-hand, and so increasing your cadence may in fact reduce your over-stride. If this doesn’t work, other cues I use with my clients are to “land under your hips” or “pull through with your knees”.
Running the same distance, at the same pace, on the same surface at the same frequency per week, puts huge amounts of repetitive stress on the muscles and joints of running. It’s no surprise then that people present with overuse injuries from high volumes of unvaried running.
Increasing running speed requires more of a fore-foot running pattern, increased joint angles and increased muscle activity. By varying running pace, you can change which tissues take up the load, which can greatly reduce the repetitive stress placed on body.
The advice I give most of my clients is to break up your training into three different types of runs. A long run, a shorter “tempo” run and an interval run.
The long run is aimed at getting kilometres under your belt and should be completed at a comfortable pace where you feel you can speak in full sentences while running.
The tempo run should be shorter and faster. If training for an event, this should be completed at your target “event-pace”.
Finally, interval training can take many forms. The most common form is to complete some Walk:Run intervals of varying distances, but at higher speeds.
A sample weekly program for an athlete training three times per week for a 10km fun run could look like this:
|Long, Slow||10km||5:30 min/km|
Running places five times your body weight on the hip joints and up to 12 times your body weight on the knees (Van den Bogert et al 1999). In order to run safely and efficiently, you need the strength in the right muscles to absorb these loads.
The number one biggest shock absorber for running is the calf. The calf has been reported to provide 60% of vertical shock absorption associated with running and jumping. Therefore the calf is king! Other muscles that can assist with shock absorption and power are the quadriceps (front of thigh) and gluteus maximus (buttocks), while the abdominals and gluteus medius and minimus (side of hips) are crucial for core stability.
Below is a simple 15-minute, 3x/week, program to improve strength in the above muscles. The novice runner may choose to start with two sets of each or with double support variations for bridges and heel raises, and on your knees for the plank variations:
|1. Lunges||Quadriceps, Gluteus Maximus||10-15 ea||3|
|2. Single-leg bridges||Gluteus Maximus, Hamstrings||10-15 ea||3|
|3. Side-plank||Gluteus Madius, minimus, lateral trunk||30 sec hold ea||3|
|4. Front-plank||Abdominals||30 sec hold||3|
|5. Single-leg heel-raise||Calf||10-15 ea||3|
Disclaimer: If you are injured, or history of injury, you should always consult your physiotherapist or exercise physiologist for a safe and specific exercise program that is tailored to your needs.
Load refers to the duration and intensity of stress placed on the tissues of the body. Load is our friend. Load is what stimulates our body to increase muscle size, build bone, increase cartilage thickness and improve cardiovascular fitness. However, too much load, or sudden changes in load can dramatically increase injury risk. So how do we measure load? And how much load is too much load?
With the ever-progressing field of wearable technology, there are more and more ways to measure running loads placed on the body including heart rate, GPS, cadence and ground-reaction forces. However, one of the easiest and simplest ways to measure load is by calculating your arbitrary units (AU) – catchy name I know! AU is basically how long you ran, multiplied by how hard you felt you were running. In other words:
Load (AU) = Duration (min) x Rating of perceived Exertion ( /10)
Whether training for a marathon or a five kilometre park run, in order to improve your fitness, endurance and speed, you will need to progressively increase your training loads. So how do we do this safely? The rule of thumb is to increase weekly training load (ie. AU’s) by no more than 30% per week. This target zone of has been termed the “sweet-spot”, while an increase in load of greater than 50% has been termed to “danger-zone” for increasing injury risk (Gabbett 2016).
Whatever your level, running is a great form of exercise for long-term physical and mental health. The ability to remain injury free will greatly improve your enjoyment and longevity of running. These five principles of optimal cadence, reducing over-stride, variable running distance, strengthening and load management form the foundation of a long and successful running career. However, this should not replace a thorough treatment plan and running analysis in the injured runner. Get your injuries treated, get your body right and keep moving!
Brodie is a senior physiotherapist at South Melbourne Physio. He has a passion for sporting and running-related injuries and is available for physiotherapy consultations, exercise rehab classes and running analysis.