Running Science with John Brewer | EP#80
Professor John Brewer, author of "Running Science", discusses some of the most commonly discussed topics in running and what science has shown to be true (and not) about them.
- Let's discuss this episode and the topic in general. Post any comments or questions in the comments at the bottom of the shownotes. I'll be here to reply and take an active part in the conversation, so don't be shy!
- I'm especially curious, have you done lactate or metabolic testing? If so, what did you find, and how did you use the results to improve your training?
- Join the discussion here!
In this Episode you'll learn about:
- Running form and technique
- The "best" way to train - intensity and volume distributions
- How body weight impacts running performance
- How age impacts running performance
- Recovery requirements for different kinds of runs
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About John Brewer
- Professor of Applied Sports Science at St. Mary’s University in the UK.
- He has a long and illustrious career in both academia and in the sports industry.
- Chair of the British Handball Association during the London 2012 Olympics and of the British Ski and Snowboard during the 2014 Sochi Olympics.
- A board member of UK Anti-doping.
- An experienced runner himself. He has completed the London Marathon 19 times.
What is Running Science about? How is the book structured and who should read it?
- The book encapsulates everything that I’m passionate about as both a scientist and a runner.
- This is taking the latest cutting-edge science, writing about it and translating it into terms that your everyday runner can understand.
- This book is not really a high-tech science book but it’s also not a beginner’s manual.
Running form and technique
- The human body is designed to run. We used to run many thousands of years ago to avoid being preyed upon by animals who are trying to catch us and we needed to catch our own food. Running is part of our daily lives along with walking.
- The problem for many people is that society has evolved with its cars, trains, and remote controls. We’ve actually taken running out of society.
- What I tend to say is let people run naturally. Let people run in a way that suits them because we’re all built slightly different. We have different anatomic joints, different bone lengths, and so on.
- Quite often, the person who might look the most ungainly is actually good at running. They’re very economical. They’ve evolved a running style that suits them.
- As a coach or as a scientist, it’s possible to sometimes try to unlearn some of the obvious problems like overstriding.
- But if you try and tinker too much and make finite adjustments just because something may then look more aesthetically pleasing, you’re actually doing more harm than good.
- Let people run in a way that maximizes their anatomical physique that makes them as economical as possible.
- Don’t tinker too much but if you do have an obvious problem, then, of course, go ahead and try to unlearn that.
What are some of those obvious problems that may come up?
- When you run, you move in a forward direction. Every movement that is counter to that like arms swinging across the chest is causing a momentum that is in the wrong direction.
- That means that you have to use more energy to go in the direction that you want to go. It’s about making sure that everything is aligned. The arms, legs, head, and trunk should all be moving in the same direction.
- There’s also a tendency to look at the point of impact – the foot. We know from scientific studies that 2-4 times body weight is going through the foot and the lower body every time the foot hits the ground.
- It’s quite easy to look at that by doing treadmill and gait analysis to work out the best point of impact. There are forefoot runners who tend to land on the front of the foot and rear foot runners who tend to land on the heel and then pivot forward.
- There is an increasing body of thought that we should land more in the forefoot manner as we’re running. That’s why we see barefoot running and minimalist shoes coming to the running market.
- On the other hand, there are also those who say that landing on the heel, which is the more solid and stable part of the foot and then gently pivoting forward, is the best way.
- What you need to do is look at the individual in a holistic view. If we’re looking at how they run, let’s also bear in mind the experience - how many years they have spent running, how much strength and conditioning have they developed within the bones, tendons, and ligaments to absorb different types of impact.
- Only then, perhaps, you can prescribe some changes because if you’ve got inexperienced runners and you try to prescribe changing too quickly – for example, you try to turn to them from a rear foot runner into a forefoot runner – there is always a danger that you might create an injury.
How much science is there on running form and specifically on how to hit the ground with your foot?
- It’s fairly unclear even to scientists. There are studies that suggest that forefoot running can be more economical. At the same time, there are also studies that suggest that you might be more predisposed to injury if you land on the forefoot.
- There are biomechanics studies that show that a gentle pivot forward from the heel to the forefoot is a very economical way of running and you are more protected by landing on the heel.
- The scientific evidence sways depending on what your genuine passion and point of view of them are.
- It’s really a case of working out what suits you, your experience, and your running style.
- I would never prevent somebody from trying a different type of running style but if that style starts to feel awkward and uncomfortable, it’s the body telling you that it’s not quite right.
- Although I’m a scientist, I will say strongly that it’s important that you listen to your body and you react to what your body is telling you.
- Obvious problems to try to unlearn include movements in directions countering our forward momentum (like side to side movements), as well as overstriding (you should strike the ground with your foot right underneath your centre of mass).
- How your foot hits the ground, with a forefoot, midfoot or rear foot strike is not necessarily something you need to change. The scientific evidence on this sways depending on what your genuine passion and point of view of them are. Find the way that suits you best.
The "best" way to train - intensity and volume distributions
- You must not do too much if you’re starting from scratch. There’s always a trade-off between intensity and volume.
- It’s important that people don’t get carried away in doing high volume, high-intensity training at the start of a training program.
- The science shows that building a good aerobic base is absolutely critical. That is the work that will build up your oxygen uptake – your VO2max – and develop a capacity to take more oxygen from the air that goes into the lungs and into the working muscles.
- This can come from two types of training. It can come from the longer, slower distance running. It can also come from threshold running where you’re running at the level where your body is producing lactic acid but is able to clear that lactic acid from the system at the same rate that it's being produced.
- The more you do this combination of aerobic and threshold training, the more you’re likely to increase your oxygen uptake.
- Once you’ve reached the ceiling where your oxygen uptake won’t go too much higher, you can then start to do more threshold work to improve your ability to sustain a higher percentage of maximum.
- This is the type of training where the body becomes conditioned to living with the lactic acid that it is producing.
- Don't do too much too soon, neither intensity nor volume.
- Realise the importance of building a strong aerobic base.
- Both long, slow distance running and threshold work can be useful for increasing your VO2max (which is your aerobic performance "ceiling").
Are there specific studies or evidence on the use of threshold training for that purpose as opposed to VO2max intervals?
- There are studies that show that a combination of both VO2max and threshold training really do give you the marginal gains.
- What we know from scientific studies is that the days where people thought that just doing mile upon mile is the best way of developing aerobic fitness are gone.
- We know that once you’ve done an element of that to develop an aerobic base, you can focus on the shorter, higher intensity work where you’re working at a much higher intensity, a much higher percentage of your VO2max.
- Of course, those runs aren’t easy. They require effort, cause fatigue, and a bit of pain but benefits are very great because you’re pushing your body to that threshold level and beyond.
- This means that when it comes to racing, you have pushed the boundaries. You have developed a higher oxygen uptake and capacity. You’ve also developed an ability to tolerate lactic acid.
- When it comes to tolerance, there are a lot of studies around high-intensity interval training (HIIT). In many ways, HIIT has been around for a long time.
- Polarized training is very suitable for elite athletes. It’s a type of work that they will benefit greatly from. It gives them those extra percentage improvements.
- For the less elite athletes, there are lessons that they can learn from it. It’s certainly something that they can incorporate into their training.
- For me, it’s the blend. It’s making sure that it’s one part of an overall training program and not something that you do on a regular basis.
- If you start doing polarized training, do it gradually and build it into your training rather than start to make it a major part.
- If you do too much too soon then there is always a risk of injury occurring.
- Whereas injury is an occupational hazard for many runners, it’s something that you can avoid if you structure your training carefully and properly.
- What we must not do is get hung up on the percentages. This is a case of making sure that we have a blend of training and a progression that starts to improve the intensity and the volume that you do.
- Gradually overload the body, reduce recovery periods, increase the length and intensity of the higher intensity sessions.
- Those marginal improvements in difficulty will lead to improvement in performance.
- Focus on creating a structured training program with appropriate progression, rather than trying to make your training program fit into certain percentage parameters.
How does body weight affect running performance?
- Having extra body weight means that the body needs to produce more energy to get you from point A to B. Having a lower body weight means lesser energy.
- If you’re carrying extra weight, the body will fatigue more rapidly. Your performance will suffer. Your times will be longer.
- If you have lower body weight, up to a point as long as you don’t start to lose muscle mass, the body will be lighter and your energy can be used more effectively and efficiently in getting you around a run quicker and with less fatigue.
Are there any numbers in terms of performance decrement per kilogram of body weight?
- If you look at somebody’s oxygen uptake, which is a function of their body weight, and you’ve got to run in 70 kilos, if you add a kilogram of weight, it’s likely that they’re VO2 max and oxygen uptake will decrease by around 1-1.5%.
- Depending on your body weight, every kilo of extra weight will lead to that 1-1.5% decrease in performance.
- That kilo will cost proportionately more for a lighter runner. If you’re a runner that’s around 50 kilos in weight then an extra kilo could actually result in around 2% deficit in performance. It is a small amount but it’s still significant when it comes to the ultimate time that you’ll produce.
How age impacts running performance
- There are two key areas where age affects performance.
- The first is that we have a condition called sarcopenia. This is where the body naturally loses muscle mass as we get older. This can reduce strength.
- From the age of around 25-30, we know that our oxygen uptake capacity will also reduce.
- This will inevitably result in a decrease in performance. You tend to see decreases in speed and power before you see a decline in endurance.
- What is encouraging is that with training, it is possible to offset the physiological declines that we get with age. So, there is nothing to stop somebody to perform at a high level in their 60’s, 70’s, or 80’s.
Recovery requirements for different kinds of runs
- If you do longer steady state running like running for 1-1.5 hours or even longer, then the main cause of fatigue would be a loss of energy stores and the loss of glycogen.
- This is where your post-exercise diet and hydration is critical to replace the carbohydrates and fluids that were lost.
- On the other hand, if you have done shorter, higher intensity sessions like intervals, then it’s more likely that the lactic acid accumulation and to some extent muscle soreness and damage to muscle fibres will be the key factor in terms of having to recover.
- After higher intensity sessions, it’s more of a case of proper rest and ensuring that your next session is a lower intensity session to give the body the chance to recuperate. Having a blend of carbohydrate and protein in the diet is needed to help in the muscle repair process.
- Ensure that you do a proper cool down to keep blood flow going and to dissipate the lactic acid produced during the higher intensity sessions.
More on cool-downs
- There isn’t much scientific evidence that suggests that cool-downs are absolutely critical.
- To learn more, see Cool-downs – are they necessary? | EP#36
- It is more of a psychological benefit than physiological. What I tend to do is just slow down in the last 2-3 minutes of my training session as part of the cool-down.
- There is a good opportunity to do some gentle stretching after a session because the muscles are warm.
- If you’ve done a very high-intensity session where lactic acid levels are high then there’s some benefit in gradually bringing the body back down to normal. Your heart rate slows down. Your cardiac output decreases. At the same time, you start to clear and exhale the lactic acid produced.
- If you do a track session, your cool-down could be something no more complex than picking up your gear from the side of the track and walking slowly back to the changing rooms.
- Sometimes we overemphasize the role of cool-down. Warm up is vital particularly as we get older to generate blood flow and increase muscle temperature so that the muscles are more pliable and less likely to get injured. This is to increase also the pliability of the tendons and ligaments to get the synovial fluid more lubricated and warmer.
- This is a beginner’s marathon running book that uses science to help beginners make the journey from the start to the finish of the 26.2-kilometre marathon easier.
- I’ve done lots of work around the marathon for many years advising runners before the race itself. It has always amazed me how desperate they are for information and how little some of them know about the demands of the race that they are about to enter.
- The book is designed to help people complete their first marathon. It’s a collection of chapters on the science of preparing, the science of race day, the science of nutrition and hydration.
- This is an ideal Christmas present for the person who is about to do their first marathon, who needs some excellent advice on how to make the training, the day itself, and the recovery.
Favorite book, blog, or resource related to triathlon or endurance sports:
Favorite piece of gear or equipment:
What you wish you had known or done differently at some point in your running career:
- Continued racing even when I had children
Links, resources and contact
Links and resources mentioned
Connect with John Brewer
Connect with host Mikael Eriksson
Hi! I'm your host Mikael,
I am a full-time triathlon coach and an ambitious age-group triathlete. My goal is podium at the Finnish national championships within the next few years.
I first started the website Scientific Triathlon in autumn 2015 as a passion project to share my learnings with a larger triathlon audience. Later on, in early 2017 I started the podcast That Triathlon Show.
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Let's discuss this episode and the topic in general. Post any comments or questions in the comments below. I'll be here to reply and take an active part in the conversation, so don't be shy!
I'm particularly curious about which of these points you consider most important to you. How do you consider changing your run training based on the information you learned here?