Most runners will have known the frustration of having to ease back or even stop training because of injury, especially if it's just before a race. Yes, that dreaded R word.....REST!
A 1992 review by van Mechelen found that runners experienced an average of 2.5 to 12.1 injuries per 1000 hours of running with 50-75% of all running injuries attributed to overuse from repetitive movement or stress. Worringly 30-90% of running injuries caused training to reduce or stop, with 20-70% of injuries requiring medical intervention.
Overall the highest risk factor for injury in both men and women was a previous injury. Using orthotics and being a novice runner with less than 2 years experience were also noted as increasing your risk of getting hurt.
Another risk factor was weekly mileage, with the highest risk at 40+ miles for men and 30-39 miles for women.
If the single biggest risk factor for a running injury is a previous injury it makes sense to prioritise not getting injured in the first place!
How An Injury Happens
This diagram shows the Theory of Homeostasis.
Zone of tissue homeostasis = the zone of safety where the tissue can cope with the physical demands required of it
Zone of supraphysiological overload = the zone where the tissue is stressed and starts to experience micro-trauma. This might be felt as muscle or joint soreness, tension, stiffness, tightness, mild inflammation or fatigue.
Zone of structural failure = the zone of injury! This is where the tissue can't cope with the demands being placed on it and it breaks down.
Training programmes will typically take the body into the zone of overload, followed a period of less intense activity or rest to allow the tissue time to repair and move back into the zone of homeostasis (safety) before ramping up the workload again.
Repeating this process makes the zone of homeostasis bigger. In other words, increasing the margin of safety for the body to perform in without getting injured.
You can also see that the zones of homeostasis and overload get smaller with very high frequency or repetition (over-training), increasing the likelihood of slipping into the zone of structural failure.....INJURY!
How can you maximise your training gains without over-training and causing an injury?
That's what this study attempted to investigate.
Project PR: The Personalised Recovery Study
This study was conducted by WHOOP in partnership with Outside Magazine to better understand the relationship between training, recovery and performance. Elite runners Mary Cain and Nick Willis were recruited to design a training programme for the study.
If you're wondering what WHOOP is, it's a wrist or bicep worn health tracker that measures strain, recovery and sleep. By measuring heart rate variability (HRV), resting heart rate (RHR) and sleep performance WHOOP calculates a recovery score that indicates how ready your body is to perform.
How The Study Worked
The runners were divided into 3x experience levels, which determined their weekly mileage and intensity:
Beginners
Advanced
Expert
Each of these groups were then assigned into 3 further groups, each with it's own method of following the 8 week training programme:
WHOOP Dynamic - regulated their workouts based on their WHOOP recovery score.
Recovery score of >67% = green. Participants can do the scheduled workout for that day
Recovery score of 34-66% = yellow. They should reduce the length and intensity of their session.
Recovery score of <33% = red. Participants should reduce duration and intensity even more.
WHOOP Static - used a WHOOP strap but didn't adjust their workouts according to their recovery.
Control - did not use a WHOOP strap at all.
Here's what the Dynamic training plan looked like with workouts based on green, yellow and red recoveries:
Before the study started the participants completed a time trial or shared a recent 5K time to establish a baseline performance level.
Over the 8 weeks of the study the participants logged all their runs on Strava to check compliance and self reported any injuries. The WHOOP users also logged their daily strain, recovery and sleep data.
The participants were asked to stop any additional cardiovascular activities for the duration of the study, but were allowed to continue other activities such as Yoga or strength training if they were already a part of their regular routine.
At the end of the 8 week training programme all runners completed a 5K time trial.
So What Happened?
These results testify to the benefits of committing to a training plan, and of exercise in general.
Let's see how each of the groups fared:
As you can see all experience levels and groups improved their 5K running times.
But what's interesting is the amount of work it took to achieve those gains and the amount of injuries they had along the way.
The WHOOP Dynamic group were up to 32.4% less likely to experience an injury. Common injuries reported were shin splints, Achilles tendinopathies, muscle strains and bone stress reactions.
In addition those in the WHOOP Dynamic group trained on average 80 mins less a week than runners following the Static protocol who logged more mileage with higher effort.
This graph illustrates how the runners fitness improved over the 8 weeks:
Even though their workload was increasing by around 10% each week their bodies were recording less strain. In other words, they were better able to handle more mileage and intensity because they got fitter.
You can also see how little difference there was between the Dynamic and Static groups, even though those in the Dynamic group were running less.
Key Takeaways From This Study
Runners in the WHOOP Dynamic group experienced nearly identical gains in fitness and speed compared to the Static group, but they did less work. In other words, volume isn't always the best or only way to improve fitness and performance.
Train smarter, not harder. By measuring your recovery and adapting your training session accordingly you can get fitter and run faster with less injury. Win, win!
A personalised training plan is crucial for success. It's very easy to download a bog standard generic programme from the internet or follow a video on YouTube, but every runner's body is unique and will respond to training differently. Using a health tracker will help you identify trends so you can reduce the risk of over-training and getting injured.
What could you do with an extra 80 minutes a week?
Do you want some help with your training programme or are you worried about injury? Book onto a Power Hour call with me and let's get you moving forwards towards your desired goals. You can also email me at [email protected].
{Study data table and graphs courtesy of WHOOP]