Runners are getting faster, whether it’s shoe tech, altitude or something in the water there’s no denying that the times are getting fast. As we know, aerodynamic resistance increases with the cube of speed which means the impact of aerodynamics becomes important very quickly. Recently, we’ve seen an example of this.

When Josh Kerr broke the mile world record he added his name to a list of record holders that had not been changed for 27 years. Clocking 3:42.66, the British 28-year-old took 0.47 off the world record running at a speed of 25.93 km/hour.

Kerr’s attempt was planned months in advance. Rather than quietly targeting the record, he publicly committed to it, building an entire training cycle around running one mile faster than anyone in history. Every decision was made with a single objective in mind.

Training, of course, was the foundation, but the margins came from everything around it. Kerr and coach Danny Mackey leaned heavily on physiological data, monitoring sleep, recovery and heart rate variability to balance workload and reduce the risk of overtraining. Away from the track, he installed an altitude chamber in his bedroom and an oxygen-enriched training room at home, allowing him to maximise adaptation between sessions.

World records aren’t solo efforts, and Kerr’s was no exception. Two pacemakers guided him through the opening laps at precisely the speed required for a 3:42 mile split, allowing him to settle into rhythm saving energy while drafting behind them. Kerr went through the first 400 metres in 55.3 seconds and then through 800 metres in 1:51.1.

By the final lap, with the pacemakers gone and a roaring London crowd behind him, the race became a battle against history. Kerr accelerated down the back straight and pulled clear of rival Yared Nuguse. Forty-five seconds later, he crossed the line in 3:42.66, becoming the fastest miler the sport has ever seen.

Josh Kerr didn’t visit a wind tunnel once during the preparation for this attempt, as far as I can tell. Should he have? He ran just shy of 26kph, speeds more commensurate with cycling than running. Aerodynamic drag in running is worth between 10 and 15 percent of the total work done against resistive forces. Perfect drafting is worth around a quarter of a second per lap, though this was “banked” and he used the first three laps worth of energy saving to empty his anaerobic energy stores in the final lap. This is about 0.75s worth of energy saved, slightly more time than the amount he broke the record by – it’s clear drafting helped him here.

During the final lap, without drafting, Josh Kerr ran 54.9 for the final 400m, this is a speed of 26.2kph and at this pace a 5% reduction in cda would save him a 10th of a second. To put that into “time trialese”, that would mean finding a saving of around 3W, this begs the question as to whether or not Josh Kerr should be wearing aero socks and aero sleeves.

The key takeaway for normal runners here is probably headwind related. It’s pretty hard for us mortals to get up to an air speed of 26kph unless we’re running into a headwind, but the energy savings of drafting if we’re running into a headwind can be significant, in the realms of 5 to 10 seconds over the course of a 5k Parkrun.

We’ve heard through the grape vine that some runners are using myWindsock to prepare for races, do the same by clicking here.

The second race against the clock has just taken place in this year’s Tour de France and it was an interesting watch from the perspective of an amateur time trialing enthusiast. The course started in Évian-les-Bains and was relatively short at only 26.1km in length, but the terrain made it truly challenging. The first 10km was completely uphill, with riders ascending the Côte de Larringes (a 9.6km climb at an average 4.2% gradient, though in real terms it was 9km at 5% then a plateau). From there, the road went back down again into a rolling, net downhill run-in to the finish in Thonon-les-Bains.

The synopsis was simple – a hard climb, a fast descent then a flat-ish bit. Watching the riders prepare and execute their races, as well as a little bit of insider knowledge, we took away some tips from watching the pros that can help you prepare for your next time trial.

The race played out as we might expect, the hilly course proving too difficult for the time trial specialists. World champion Remco Evenepoel stormed to victory, stopping the clock in 32:19 to claim his second stage win in a row with what we think might be the best time trial performance in history.

1. The harder the effort, the harder the warm up

The club 10 is a staple in basically every single myWindsock user’s diet and, while this race was a little longer than 10 miles, it was a similar-ish duration. One thing we noticed from the images of the riders preparing is how hard they looked like they were going on the turbo.

Riders interviewed afterwards were talking about how hard they went on the climb, with one saying his plan was to do the first 10 minutes at over 550W.

The harder the race, the harder the warm up should be – especially in instances like this, with a fast start. Riders were doing around an hour in some cases, though the literature suggests this isn’t necessary. Some time in each energy system progressively with one or two 15s efforts at the end is probably all you need, but don’t be afraid to go very hard, pop a gel afterward to replenish your depleted glycogen stores.

2. Don’t pace it evenly

The hard climb at the start takes us nicely onto the fact you should not pace any time trial evenly unless it’s a dead straight line with no elevation, corners or speed changes – and even then you should ride hard at the start to accelerate yourself. In order to simulate Remco’s 32:19 on this course, we had to input some obscene numbers. The average power we estimated for him on this course is around 405W, though this is heavily weighted in the first half of the course.

If we take that same average power of 405W but just ride a flat pace over the course, with other conditions all exactly the same, the time predicted comes out as 34:15, just shy of two minutes slower!

3. Climb in the TT bars – even when going slowly

All of the top riders rode the climb hard, but stayed in the bars. There was no standing up and swinging the bike around underneath them.

4. Use myWindsock to prepare

A quick look on Strava after every stage will show you that a decent proportion of the World Tour peloton are using myWindsock. We also know that many of the teams are using it to prepare for time trials and road stages. If you want to be as the best – click here.

Every year, the heat becomes a bigger topic of the Tour de France than the year before. This year, it’s become such a problem that, friend of myWindsock, Victor Campenaerts has foregone his socks. France has always been pretty warm in July and heat has always been a problem at Le Tour, but it does feel like it’s starting to get dangerous with ever increasing temperature management protocols from participating teams.

The other factor worth bearing in mind is that France is a massive country, at least in European terms. Every Brit can recognise the vast climactic differences between Scotland and Cornwall – if you drove this distance from Calais, you wouldn’t even reach Toulouse. If the Tour spends more time in the south these days, it may appear as if it’s getting hotter than it is in ‘real terms’.

We need to investigate if France is getting hotter as well as if the route is getting hotter too. For this, we will require a very specific set of skills and a slightly odd need to investigate such issues. If only there was some kind of website that would allow us to investigate this sort of thing…

Is France actually getting hotter in July?

France’s capital city is Paris, which in Summer can get quite warm and seeing as large urban populations typically have slightly more robust historical record keeping, we will use this as our initial benchmark. The data we’re using for this graph is from the French government and you can investigate it yourself if you like.

Since 1960 we see a slight upward trend of the daily average temperature with clear signals of heatwaves. Daily highs above 25 degrees have become more common and this has been felt more clearly since 2010. The microclimate of one city’s temperature gauge is not indicative of a broader pattern but if you were to ask the question of “are riders more likely to be sprinting up the Champs Elysees while warm today or in the past?” the answer would be that today is likely to be hotter.

Is the route getting hotter?

The below weather map is from France on the 12th of July 2026 in the afternoon. You can clearly see that the temperatures are distributed quite unevenly but there’s a rather warm patch in the middle. Le Tour actually went straight through this purple patch today and they shortened the stage by 30km as a result of this. It may be the case that routes have to be written with the temperature in mind in the future.

If we were planning the Tour de France, obviously we’d think about the weather first, seeing as that’s all we ever think about at myWindsock. This year, riders have been particularly unlucky in that they’ve been racing during a “heatwave”. Meteorologists typically declare a heatwave when daily maximum temperatures exceed a location’s specific average threshold for three or more consecutive days. As the average temperatures are drifting upward, heatwaves themselves are also getting hotter.

Certain parts of France’s geography are predisposed to heat and organisers should think about avoiding sending the race there in July. The final stage is an evening lap of Paris, which isn’t usually too hot especially as the riders don’t actually race it particTularly hard until the final hour of the race.

What should organisers actually do?

France is gradually warming up, along with the rest of Europe. Heat waves are becoming more common and they’re obviously both more likely and more severe in July. It seems that the position in the calendar is part of the problem, during the pandemic of 2020, organisers had no problem moving the race – ostensibly for the safety of the public and riders. A Wikipedia dive would show you that Le Tour has always taken place in July but there’s no obvious reason as to why that is.

It seems to me the organisers have two choices, one is to move the race to September or May while the other option is to stick to the edges, north and mountains of France and ditch the heat basin in the middle if they’re going to insist on the race continuing to take place in July.

The best way to plan the Tour de France would be with a myWindsock subscription. That way organisers could check historical temperature records along the route of each stage to make sure they’re not putting riders in danger.

Stage 1 of the Tour de France this year is a 19.6km lap of Barcelona. The weird thing about this year’s tour is that riders get their own individual time on GC, rather than the entire team getting the same time as the 3rd or 4th rider across the line. This opens up a conundrum for teams of where they burn their riders. It’s likely we will see a number of pacing strategies throughout the stage, with some teams keeping more riders for longer and others having riders peel off early.

Some useful information

If you’re travelling up a 7.5% gradient, this study modelled the impact of drafting at various speeds.

Our recommended strategy for using riders

As the rules have recently changed, teams will most likely employ a wide variety of strategies during Stage 1. The forecasted wind being low added to the fact that central Barcelona is sheltered from the wind with tall buildings means the majority of our attention will go to the elevation profile rather than wind. The climbs themselves are draggy so the riders will ascend them extremely fast and drafting will play a large role on these climbs. Overall average speeds on this course will be high.

We know a team starts with eight riders and they’ll want two or three for the final climb (depending on who their GC guy is and their physiology), the second to last climb will take two to three riders doing a final full gas 45 second turn each.

A best starting point for a pacing strategy as a result of this is all eight riders sharing the work for the first 15km with two guys pulling double turns and doing a final turn each into the bottom of the penultimate climb.

That leaves 6 riders into the bottom of the second to last climb. This climb is the shallower and longer of the two and will probably be ridden between 90 seconds and 2 minutes. Using two riders there leaves you with four into the final climb.

Alternatively, for teams like UAE and Visma with proportionally stronger GC riders, they might want to use more riders pulling shorter, harder turns on that second to last climb to allow their GC rider to do a harder final effort.

A not so well kept secret is most of the teams are using myWindsock to plan their pacing strategies, you can too here.

This weekend marks the 2026 RTTC National 50 mile championships. Riders will tackle a 3 lap course near Congleton in the North West of England. View the J4/34 course forecast.

Set just two weekends ago, the course records on the new J4/34 course are 1:47:29 and and 2:11:58 for men and women respectively – though after Sunday’s national championship we suspect both of these records will fall.

The wind sheer plot shows that the course is mostly protected from the wind. The dark sections of the overlay show where wind is reduced due to surface friction (caused by hedges, hills and more). The lighter sections are more exposed so the relative wind speed is higher – though forecasted speeds for Sunday are relatively low in general.

The terrain

Although we’re expecting some fast times, the course is not flat. Each lap descends into, and climbs out of, the River Dane valley twice. Most of the climbing and descending is on moderate gradients, so it should still be a day for the big chainring. However, a significant portion of the route is above 2%, and with a maximum gradient of 6.1%, some riders may find themselves wishing they had more than a single chainring.

We can see from the elevation profile that the course rolls gently. For some riders, depending on your personal preferences and physiology, this kind of course can be an advantage as it allows recruitment of different muscles as the gradient gently changes. Riding a long, hilly, time trial is an art form – and we have a specific guide on this here.

The weather and the wind

The weather has been in the news a lot this week, it’s hot up and down the country! Sunday’s forecast is much milder than this week. Riders shouldn’t have to make heat adjustments to their pacing plan for the race. The broad forecast summary is for moderate temperatures with a chance of showers.

The wind adjusted elevation tells the story of the day – wind is forecast to be mild 3.5m/s (7.5mph) and the course is relatively sheltered. The wind will add roughly an extra 35m of elevation each lap to the ride feel.

In terms of the course obstacles, there’s a couple of roundabouts to negotiate so early riders may see a traffic advantage before the Sunday shoppers head out at 10am.

All in all, it should be a good day for some faster than expected times with moderate temperatures and extremely still conditions. That paired with a pretty decent road surface and a successful test event, Congleton CC – myWindsock is looking forward to welcoming you to the race! See you all on Sunday.

Do you want to prepare like a pro? Sign up to myWindsock here.

Have you ever Googled “How to ride my bike faster”? If you have, this one’s for you. If you were to raise your FTP by 10 Watts it might take you between 8 and 12 weeks depending on your level of experience and the quality of your training – but you can get 10 Watts faster overnight by paying more attention to your aerodynamics!

This blog is not one that’s about to tell you to simply spend £300 on uber chainwax or £1500 on a new front wheel but how you can train yourself to ride faster, not harder. This is our top 3 sessions on how to get faster at cycling, without getting fitter.

Top 3 sessions to ride faster, not harder

Session 1, the v:P maximiser

The aim of this session is to ride as fast as possible for as low an average power as you can. The goal is to maximise the ratio of v (velocity) to P (power). If you’re feeling extra fancy, you can “normalise” your score on this session by using the wImpact. In order to execute this session you take the following three steps…

1. Pick a route with as few interruptions as you can reasonably find. In order to compare sessions and show improvement, you’ll need to repeat the session on the same route.
   
2. Ride the route as fast as you possibly can, while going at a fixed average power (or choose an average speed target and try and ride as easily as possible).
   
3. Analyse your ride in myWindsock, divide the ratio of your speed to power by the wImpact score and rank your rides. Hopefully you’ll see yourself improving over time.

You can improve your speed by playing around with where you use your power, holding experimental aerodynanmic positions while you ride or try out new kit!

Session 2, the Threshold Barber Chair

Maybe it’s just me, but I find getting a haircut extremely awkward as I’m forced to stare at myself in a mirror for half an hour. That’s why I called this session the threshold barber chair – as it requires doing threshold efforts with a mirror. The aim here is to prevent lazy position slipping throughout your TT.

1. Plan to do your threshold session on the turbo and set up a mirror in front of the turbo.
   
2. Do your intervals in the aero position (or holding an aero tuck if you’re on a road bike).
   
3. Aim to keep yourself as small as possible throughout the efforts, using the mirror as a guide.

If you’re feeling extra committed, you can do this session indoors with your TT helmet on to optimise helmet and back interaction – but please keep in mind this could boil your head.

The yoga matt

This session isn’t really a session, more of a reminder. You’ll be able to hold your aero position more easily if you’re stronger. The main thing to do is, when you’re riding around in your most aerodynamic position – pay careful attention to what fatigues, aches and hurts. These are the areas you can focus on in the gym. It could be anything from hamstring flexibility to tricep strength and what to focus on will depend on your body and your position.

Getting faster and getting stronger are not the same thing. You measure your strength with your power meter but the most effective (and probably the most cost efficient) way to measure your ability to go fast is with a myWindsock subscription.

We’re into hot day season, with a heatwave arriving in the UK it feels like a good time to talk about density. The density of the air is essentially “how many air particles exist in each metre cubed of air”. This is the cause of a day feeling slower than it should be. It’s usually the culprit of a windless, perfectly temperatured and otherwise faultless evening time trial being unreasonably slow for no reason.

Pressure and density are related, and if you’ve ever been on a trip away to the mountains, you might notice it on your weather trends plot…

The maths

Density, pressure and temperature are all related to one another (and impact the power required to ride at a given speed). We’ll start with the relationship between the three…

The way to think of the difference between pressure and density is that pressure is the weight of the air above you (this changes with different weather systems and altitude) and density is the amount of air you need to push out of the way.

How does density impact our speed?

The power needed to ride at a given speed is directly proportional to the density (and thus pressure) of the air. On those days where you find your power numbers are high but speed is low for no reason, you can often blame the density. One thing you notice when you go up a mountain is how fast you start riding for low power which got me thinking, as density changes with altitude, is there a perfect altitude to maximise every speed?

It’s not that simple though

You’d think this was an argument for doing an hour record attempt on the moon (in fact, if you had a velodrome on the moon travelling at 60kph would only need about 9W) but obviously as the density of air decreases so does the oxygen available to our muscles to produce power. VO2 max doesn’t drop linearly though, it starts off decreasing slowly before a slightly faster drop (but the point at which the decrease in VO2 max breaks linearity varies from athlete to athlete).

An hour record is typically raced at around a riders’ LT2, so we’ll use that as a reference point.

Sign up to myWindsock

This week’s blog was inspired by weather trends, you can view yours by signing up to myWindsock here.

Yesterday, we predicted a winning time of 42:54 in the Giro d’Italia stage 10 time trial. Ganna, unsurprisingly, won the stage but he did so in a time of 45:53, almost 3 minutes slower than we predicted the winner would go. In his daily vlog, Victor Campenaerts said to Ganna that Visma had predicted his time as quite a bit faster than he ended up going.

On the vlog, the pair of them were discussing the rough road surface, which can lead to around double the rolling resistance as we see on a smooth surface. Ganna was almost exactly 1km/hour slower than we predicted him to be.

How does rolling resistance actually work?

Rolling resistance is the force that slows a bicycle down as the tires roll over the road. A cyclist must continuously supply power to overcome this resistance, even at a constant speed. The main cause is that bicycle tires deform when they contact the road surface and the rougher the road surface, the more deformations there are. Tires are not perfectly elastic, so some energy is lost as heat instead of being fully returned and on a warm day, rolling resistance can actually increase significantly – especially as the road surface also heats up.

Because of this, riding on rough asphalt requires more power to maintain the same speed compared with smooth asphalt. For cyclists, smoother roads generally feel “faster” because less energy is wasted overcoming rolling resistance.

The power required to overcome rolling resistance is directly proportional to the bike-rider system mass multiplied by the speed of a rider – so the bigger and faster you are, the more this impacts you.

Making excuses

The winner of Stage 10 of the Giro, Ganna, is as big and fast as pro cyclists get. As a result, the unexpectedly rough roads will have had a larger absolute impact on him compared to other riders.

If you think you can do a better job of estimating your next time trial time, which you probably can, check out myWindsock here.

We’re going to put our money where our mouth is and try to predict the winning time of the Giro d’Italia Stage 10 TT then, after the race we’ll take a look at how we did and what this means for the first Tour de France time trial. This blog will not predict who will win the race, simply how fast someone who wants to win might have to go. The second part, which we’ll write after the TT takes place, will use Jonas Vingegaard’s data to predict his time on the TT in stage 1 of the Tour de France this coming July.

One quick caveat, the GPX files available online (that we use to make the forecast) are not perfect and sometimes race day has the start ramp or finish line in a slightly different position to where the file starts and ends. This may only be a handful of seconds over the course but it can sometimes make our predictions look worse than they actually are.

A quick rundown of the course

Stage 10, which also opens the second week of racing, is the only time trial of this year’s Giro. It’s 40 kilometers from Viareggio to Massa (a good old fashioned 25 pretty much), bringing the race back toward Italy’s western coast and the Tyrrhenian Sea.

The route is pan-flat from start to finish, with no climbs at all, making it one for the specialists where the big engines should come to the fore. With a straightforward, largely non-technical coastal course, there’s nowhere to hide, and if the wind picks up along the shoreline, it could easily become a decisive factor in the overall standings.

The weather

It’s always a little bit risky talking about the weather with all forecasts subject to change, but seeing as a motorway bridge would look like a mountain on this course, it’s worth bringing up now as it’ll form the basis of our prediction. During the course of the day, the wImpact evolves from -3.9% to 1% for the final riders.

The winning time

World Tour cyclists have crazy power numbers, and those that want to are able to make themselves very aerodynamic. The question here is how fast will the fastest rider in the fastest conditions go on this course?

With an expected winning speed of around 56kph, it’ll be interesting to see what Vingegaard does and how that translates onto the Tour de France course where he’ll face up to Pogacar and Seixas on day 1 in Barclona’s ITT!

Sign up to myWindsock here.

If you’re allowed to share the work, why does a TTT feel so much harder than an individual time trial? This is, of course, dependent on the team. I’ve been in team time trials where I’m the strongest rider, and team time trials when I’ve been the weakest rider yet the hardest TTTs are always when you’re sharing the workload evenly. This is because, if you pace it right, you should come off the front of the group right on the limit of being able to get on the back, only then do you start recovering.

We can turn to academia for some insights as to why this is, though studying two or more riders in a line can be quite tricky (if you’ve ever been to a wind tunnel, you’ll know they’re not that big) so people who make these studies make these useful, but somewhat comical, little cycling figurines to make measurements.

The study we’ll use to look into the physics of a TTT, in order to try and figure out why they’re so hard, looked into where in the line drag changes, the impact on spacing between riders as well as how the number of riders can make an impact. The cyclists in the study were scaled models of a 183cm tall with a bodyweight of 72kg.

Those of you with a sharp eye will notice the rider at the front gets a slight reduction in drag force too. When two or more cyclists ride in a line, the front rider experiences a small reduction in aerodynamic drag because the riders behind slightly modify and stabilise the airflow in their wake, reducing the pressure difference behind them.

We know a rider in a 4-up TT experiences on average, 65.7% (let’s say 65% for simplicity from now) of the drag force and thus, their average cda over the ride is reduced by the same amount and, as such, they’ll travel at a much higher speed for less power. There are two moments during the TTT where every rider has to hold their speed or accelerate without any meaningful assistance though, while their on the front and while they’re drifting back.

In order to return to the back of the pace-line, it’s necessary for there to be a difference in speed between the rider peeling off and the rest of the group and that speed must be made up for with an acceleration in order to ‘get back on’ as the group passes. As you may remember from school, Isaac Newton’s second law tells us that the force required to produce an acceleration is proportional to the mass of the rider multiplied by that acceleration.

This acceleration is actually the reason team time trials feel so hard, this requires some depletion of a riders’ anaerobic capacity in order to produce enough power to make up that speed difference.

If you’re setting a forecast for your TTT, you can model how fast the team will go by using a cda that’s 65% (in the case of a 4-up TTT) of your usual value, so if your personal cda is 0.23 you can use 0.15 to calculate the speed that you might travel. If you agree the power you’ll ride on the front with your teammates beforehand, you’ll be able to use myWindsock to assess what’s possible.