Can shoes make you faster? It seems they can – on a treadmill at least.

Last May I was struggling with lateral knee pain. For days after the Taunton half marathon I couldn’t walk down stairs. I had tried a few things and was about to spend a lot on a trip to a podiatrist. Instead I went to TriUK in Yeovil and had a go at their “Mizuno Running Solution”. They picked out some shoes for me and I haven’t looked back – I haven’t had knee pain since (I have had Achilles discomfort, lateral foot pain and posterior tibial tendonitis mind you – but nothing terrible). I’m on my third pair of Mizuno’s now. My wife and kids have pairs too.

I have been using the Wave Mujin 3 shoes over the winter. They have taken me through umpteen muddy fields and down paths as well as covered a lot of road miles. I have probably done 400-500Km in them. They have been through the washing machine umpteen times (I know…).

I thought it was time for some new shoes. The Nike app texted me last week to say that their new lightweight Epic React Flyknits were available. 5 minutes later I had ordered a pair and they arrived last Wednesday. They have a new type of foam in (“React”). It’s durable and returns energy to the runner. It’s no Zoom Vaporfly 4%, with no carbon fibre plate (as far as I know). But it’s not exorbitantly expensive and the shoes expected to be durable – 600 miles or so.

On Friday I took them for a spin. On a treadmill. My “fast” mile felt easier than ever – rather than feeling as though I was going to pass out at the end of it, I was increasing the speed and went on for 2Km.

Psychological? Possibly. I firmly believe in psychology. I have a degree in it, and my PhD was on “central fatigue” – the concept that your brain limits your exercise capacity. I spent a lot of time doing transcranial magnetic stimulation. It’s odd to see the resurgence recently in brain stimulation. There is no doubt that new kit gives you a boost. But certain parameters, such as heart rate don’t (shouldn’t) lie.

Last night I settled down for some science. I’ll need to replicate this again, probably next Sunday, but the bottom line is that the new shoes seem faster.

Some methods. I warmed up outside with a 3K run up and down our local hill. I then did 5 intervals on our treadmill: 800m at 11.3Km/h then 800m at 16.2Km/h then a brief rest (I let the treadmill run at 9Km/h for 400m – 160s). A total of 8K. That rest time allowed me to slow down, get off the treadmill and change my shoes and my footpod (Polar). I used a Polar H10 heart rate strap and recorded it on my Garmin 935. The first interval was with the Mizuno shoes. Then two intervals with the Nike’s. Then an interval with the Mizuno’s and then a final interval with the Nike’s. For reference I weighed the shoes – a single Nike weighs 234g, a single Mizuno weighs 388g – an important difference.

Note I can run “faster” on the treadmill than in real life. I have just managed a Sub 20 5K on the treadmill, but it’s still just over (by about 40s) on the local 5K park run. 11.3Km/h is the speed I target for endurance. Last year that kept my heart rate about 130-135bpm. 16.2Km/h is the fastest I can sustain for a mile. Because I wanted to see if the new shoes were faster I didn’t want to hit my maximum heart rate and plateau, so although I can go a (little) bit faster over 800m I kept it at this level.

What did it show?

Firstly, it felt way easier with the Nike’s. There is a definite squish and you can feel the shoe deforming on impact with your toes and forefoot sinking into the shoe. You don’t get that with the Mizunos. But was it physiologically easier?

It looks like it was. See figure 1. It has two traces on it. There is an actual speed (according to the treadmill) line to demonstrate the intervals and a heart rate trace. The orange intervals are when I have the Mizuno’s on. The Black intervals are when I have the Nike’s on.

Figure 1.

Nike vs. Mizuno

Firstly, from left to right there is a gradual increase in heart rate. For me, running the 5 back to back intervals was hard. I’m also in a small, hot stuffy room. So I get tired and dehydrated.

But the interesting thing for me is that my peak heart rate is higher on interval 4 than interval 5, by just over 4 beats per minute. The trend would suggest it should be the other way around. Not much – but around 3%.

The really interesting thing is the speed data from the footpod though. The next chart (figure 2) shows the actual speed (calibrated – the actual data suggested I was much faster than I was!). As far as the footpod was concerned I was running more slowly (about 2Km/h) with the Nike’s on compared with the Mizuno’s, although the treadmill speed was the same.

Figure 2.

N Vs. M 3

I’m not quite sure why this is. Running in the Nike’s changed my technique though. I felt a bit more tipped forward and a bit more on my toes. I also noticed a bounce, and I would imagine I spent more time in the air, allowing the treadmill to travel further beneath me.

I have summarised the data in the table (table 1). I can go faster on the treadmill in the Nike’s. But am I faster in real life? I’ll try to answer that soon. As soon as the weather dries up anyway and I have some time to do some intervals outside. I don’t want to get my Nike’s dirty yet, and time is a bit tight at the moment. I also need to do a long run first to see if they are comfortable enough. The toe box is a bit small, and I don’t know how my knee will stand up to things. If I can’t get on with them, back they will go. Despite the treadmill times.

Table 1.

Interval Shoe

Treadmill Speed

Footpod Speed Mean Heart Rate

Max Heart Rate

Interval 1 Mizuno

11.3

11.2 117

123

  Mizuno

16.2

18.0 144

152

Interval 2 Nike

11.3

11.0 118

125

  Nike

16.2

15.0 143

150

Interval 3 Nike

11.3

11.0 119

126

  Nike

16.2

14.8 142

148

Interval 4 Mizuno

11.3

10.9 124

130

  Mizuno

16.2

17.3 149

155

Interval 5 Nike

11.3

10.8 123

128

  Nike 16.2 15.1 146 151
Interval 1+4 Mizuno

11.3

11.1 120

127

  Mizuno

16.2

17.6 147

154

Interval 2+3+5 Nike

11.3

10.9 120

126

  Nike

16.2

15.0 144

150

Quakinghouse Lane

This morning I ran up Quakinghouse lane with the dogs and one of my kids. For about the first time in a while I enjoyed it. At the top of the hill the sun was rising, the wind had dropped, and I could see out over the vale of Taunton. There was a chance I would get home with warm, dry feet.

It’s been a long hard winter, and running up and down that hill hasn’t been pleasurable. But people who run (or cycle) are addicted to running (or cycling), and I am now a slave to it. And it is an addiction.

There is a long-running study looking at Ultra marathoners (the ULTRA study). It takes a little finding. There is a study on the treatment of fibroids known as Ultra, and project MKUltra is also known as the CIA mind control program – allegedly.

The signup for the study is here if you are interested. It’s an ambitious project to determine whether running long distances is healthy. If you are one of the many who has done an Ultra, then go and sign up.

But the interesting thing about people who do Ultras (people can enrol in the study if they have run an event of more than 50K) is that they don’t care if it’s healthy or not. Participants in the study were asked to answer “yes” or “no” to the question “If you were to learn, with absolute certainty, that ultramarathon running is bad for your health, would you stop your ultramarathon training and participation?” Of 1349 who answered the question, almost ¾ answered “no”. My guess is that this would hold true for cyclists and triathletes too. The Pubmed link is here if you want to read a bit more.

I see people with heart trouble every day of the week, that may be due to exercise. I haven’t stopped yet and won’t for as long as my health and my joints can keep going.

It absolutely p****d down as I ran down Quakinghouse lane. The shoes are on the Aga. I’ll be out again tomorrow.

Strava have lost Friends

Recently Strava’s API for getting Friends has stopped working. This hasn’t only affected Crickles: numerous other app developers are reporting the same problem. There is no information about this on the Strava developers site, which still reports the same protocol for accessing Friends data, so there is no way of knowing if it’s an unintended bug or a planned removal of functionality. Strava are not replying to Support queries on the topic.

Whether/how Friends-style comparisons will be supported if Strava don’t fix their API remains to be seen. Please let me know if you have views on its desirability.

UPDATE – Strava are not restoring this functionality hence the Friends groupings in Crickles are, for the time being, stuck with only the friends known as of the date before this was withdrawn.

Thanks, Ian

I don’t know what to call this one.

It’s been one of those weekends which haven’t been full of joy. At one stage yesterday, with the rain pouring and the wind blowing, I asked myself what I was doing out running up a muddy hill with the dogs. The answer was of course to take my mind of the Bawa-Garba case.

For those of you who don’t know, Dr Bawa-Garba was found guilty of manslaughter and struck off by the GMC after the tragic death of a child under her care. She made a mistake – that is clear – and it had terrible consequences. But there were, as there usually are with mistakes, also problems with the system in which she worked. She had just returned from maternity leave, was working in an unfamiliar environment, the IT system was playing up and she had with junior doctors supporting her with little experience. It has been reported that she was covering for absent colleagues, including the consultant as well. Is it any wonder that a mistake happened?

This winter in the NHS has left many of us rushing around, managing a much higher number of patients than usual, and consequently making hurried judgements. But what is the alternative – to say you will only see a certain number of patients, or down tools if members of the team are off with flu? The case has made many of us feel vulnerable. All doctors make errors at times. We know we make more errors when under pressure.

The practice of medicine relies on judgement and intuition – which is why it is error prone. It is not an exact science, and never will be.

It is that very lack of hard data that inspired Crickles. I was asked “how much exercise is too much”, and I couldn’t give an exact answer. Crickles draws on the wisdom of the crowds. You can look at your exercise volume and see where you are relative to others. You can look at your fitness and fatigue levels. As of this evening, I am fatigued according to my data. So, it’s a day off training tomorrow, thank God, as the weather looks crap.

 

 

Logging on to Crickles

Prominent amongst the latest batch of enhancements to Crickles is the introduction of user credentials: you now need a password to access the Navigator. The log-in screen looks something like this

save_password

On your first visit, you’ll only see the Username (Strava ID): field at first. The Strava ID that is needed is not the email address or Facebook ID that you use to log onto Strava but the number that Strava uses to key your data. In my case, for example, it’s 301194, as in the figure. To find your Strava ID, go to the Strava website and find “My Profile”. On the Strava website, it’s currently found in the pull-down menu next to your photo on the top right of the screen.

Once you have selected this, the top of the browser window will look like this:

strava address

You can see from the figure that the Strava ID (301194 in my case) is at the end of the URL in the address bar.

Once you enter your Strava ID, if you haven’t yet authorised Crickles to access your Strava data a link will appear where you can do this. Alternatively, you can do so at:

signup.crickles.org

Then, if you haven’t got a password yet, hit the Request password button. A password will be emailed to you and it should arrive more or less instantly.

If you wish, once you’ve logged on you can create your own password. As well as being potentially more memorable, this is also more secure. Although the password generated by Crickles is encrypted, it has necessarily passed through email servers en route to you, unlike a password that you choose for yourself.

You change password using this screen:

change_password

You get to it by checking the Change password? checkbox in the side panel. If you’re on the screen and decide that you don’t want to create a new password, simply uncheck the box. Once you’ve changed the password you’ll need to re-enter it to log in.

After you have logged in you should not usually need to do so again on the same device. (If, though, you have disabled all cookies in your browser you’ll need to log in every time.) The way that credentials are shared between devices, and whether and how passwords are cached, will depend upon your device, your browser and your settings.

Significantly, no one can now see your data on Crickles without logging in as you. Your Strava Friends who are also on Crickles can compare various aggregate CSS measures and compare charts of activities that have not marked as Private on Strava, but the detailed information that you can see is now just your own.

Crickles Charts now in the Navigator

Crickles Activity Charts has up until now (only) been available as a standalone app at charts.crickles.org. From today, Crickles Charts are integrated in the Navigator and the separate app has been retired. Here’s an example of how it looks now:

new_charts.png

For the time being, this functionality joins HR Zones and Regularity as a beta feature and thus requires a log-in.

Functionally, the only significant change is that the set of Athletes whose activities you can choose to chart against your own is now picked from amongst your Strava friends who are on Crickles rather than the entire Crickles population. If you need a refresher, a description of the functionality as it was before is available here.

Hopefully, now that charts are integrated with the rest of the Navigator functionality, you’ll find it more convenient.

More Good News If You Are

An elite athlete.

Shortly after writing my previous post, suggesting Tour de France riders live longer than normal people, I came across another study published in the British Journal of Sports Medicine. It was entitled “Mortality and health-related habits in 900 Finnish former elite athletes and their brothers”. The link is here.

 

They looked at male Finnish elite athletes who represented Finland between 1920 and 1965 and their age-matched brothers (not identical twin brothers necessarily). Fortunately having brothers seems common in Finland where it is often dark and cold.

They followed them from the start of their career up to 31st December 2015. 1296 of the 1800 died during the study period. The median age at death was as follows:

 

  Elite Athlete Brother
Endurance 79.9 77.5
Mixed Sports 75.9 73.7
Power Sports 72.2 72.2

Elite athletes smoked less and were more physically active in general. We don’t know why elite athletes live longer, but their overall lifestyle, which includes exercise, seems to be protective.

This is an observational study, and not an experiment. It remains possible that the difference in smoking rates or some other lifestyle factors made the difference, and the excess exercise narrowed the gap – the study does not exclude the possibility that exercise is harmful in excess. It also doesn’t tell you that endurance sports make you live longer than power sports – just that those that tended to do endurance sports came from families that tended to live longer.

But I’m still doing some triathlons this year. And I will still be advising my patients to exercise. I’ll dig out the paper, hopefully, and see if there are any more details buried within it that are important.

 

 

 

 

A New Post for 2018

I just thought I would share this question we were asked recently:

“Do you have any data on the incidence of AFib in people who say competed in the Tour de France in past years to see how the risks in this population compare with the public as a whole.”

There is no doubt that I see a lot of people with atrial fibrillation (AFib, AF). Most of the people I see are cyclists. And that makes me think that there is something about cycling that leads to AF. But, it could be a sampling error – all the people who get AF from other sports might go and see someone else. It doesn’t feel like that though. As I supervise the nurse led AF clinic. There are plenty of people who run too in Somerset – I only see a few of those.

Tour De France cyclists are an unusual breed. They may well be genetically different to you and I. Or at least me. And remember, at least (hopefully) until recent times, these riders were (probably) systematically doped. There were probably teams in France doping kids from the age of 11 (according to some of my French contacts), and many domestiques had to take drugs or be dropped. It started with amphetamines in the 1900s.

There are descriptions of arrhythmias in former cyclists (e.g. Europace. 2015 Mar;17(3):387. doi: 10.1093/europace/euu399. Epub 2015 Feb 12.); A left atrial tachycardia is often the start of AF. But, there are  no systematic studies that I am aware of. Overall, however, being a TdF cyclist seems beneficial to health however – they seem to live longer at least. See Eur Heart J. 2013 Oct;34(40):3145-50. doi: 10.1093/eurheartj/eht347. Epub 2013 Sep 3 and Int J Sports Med. 2011 Aug;32(8):644-7. doi: 10.1055/s-0031-1271711. Epub 2011 May 26. 

That doesn’t mean it’s the cycling though. It could be the diet, the genes, or even the drugs. We perceive drugs as harmful, but that doesn’t mean they are. When the stigma dies down, we should probably try them in the elderly. It might improve the quality of their life – sarcopenia (a loss of muscle) and a loss of cardiovascular fitness really hits the elderly hard in a variety of ways.

I’m afraid that endurance exercise does appear to predispose to AF – at least in men. The paradox is that those who exercise appear to live longer, which can get lost in all the concerns.

So AF may need to be reconsidered as one of those things that happens – like tendonitis, stress fractures and muscle strains (although a bit more serious, in my view).

If I don’t get AF this year, I’ll be doing the Dublin Marathon again in October.

Who does what on Crickles / Strava

You may have noticed on Strava that there is quite an extensive list of Sports into which activities can be categorised. Here, for no reason other than curiosity, is a chart showing relatively how many of each activity we have on Crickles:

count_by_sport.png

Since the number of activities in each Sport ranges from Rides, which is in six figures, down to Handcycles, for which we only have one, I’ve used a log scale.

Cardiac Stress Score can be calculated for any of these Sports in which a heart rate monitor is used (and estimated imprecisely even if one isn’t).

UPDATE: the algorithm for calculating CSS in the absence of heart rate data has been significantly enhanced since the time of writing.