Is less really more in warm-ups?

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As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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A few people have e-mailed me about this University of Calgary study, (“Less is More: Standard Warm-up Causes Fatigue and Less Warm-up Permits Greater Cycling Power Output”) which has received a bunch of press. It seems to run counter to the message from this blog post a few weeks ago, which argued that a hard effort during your warm-up could enhance performance.

The new study had cyclists perform either a “standard” long warm-up (designed in consultation with elite track cyclists and coaches), or an experimental short warm-up. Then they tested performance, and the short warm-up group had a 6.2% advantage in peak power. Okay, cool. This is valuable information. But let me add two caveats:

  1. What was the “standard” warm-up? It was “about 50 minutes with a graduated intensity that ranged from 60 to 95 per cent of maximal heart rate before ending with several all-out sprints.” That’s one heck of a warm-up. In comparison, the experimental warm-up was “about 15 minutes, and was performed at a lower intensity, ending with just a single sprint.”
  2. What was the performance test? It was a 30-second Wingate test.

Now, bear in mind what athletes are hoping to achieve with a warm-up. According to the paper, it’s:

[I]ncreased muscle temperature, accelerated oxygen uptake kinetics, increased anaerobic metabolism and postactivation potentiation (PAP) of the muscles.

In the blog post a few weeks ago about the “priming” effect of a hard warm-up effort, the focus was on accelerated oxygen uptake kinetics. But in a 30-second sprint, oxygen kinetics have nothing to do with it. We’re talking about two different animals here.

Bottom line: if you’re a track sprinter who spends nearly an hour warming up at up to 95% of max heart rate, then this study tells you something very important. But if your event is longer than 30 seconds (so that oxygen kinetics matter), and your warm-up tends to be shorter and less intense, don’t assume that this study is telling you to shorten it even more!

The priming effect: how a hard warm-up can help performance

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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Most people who do hard interval sessions will have noticed this mystery: why does the second or third interval usually feel easier than the first one? I always figured it had to do with “getting into the rhythm” or something along those lines. Whatever the reason, Pete Sherry — my main training partner for 2002-2004 — and I eventually decided that we’d run 2x400m in ~72 sec a few minutes before every workout, in the hopes of making the first interval feel easier. Our impression was that it worked, and we started doing it before races too.

It turns out there’s plenty of physiology behind this. If you suddenly start running at a hard pace, with no warm-up, it takes a while before your body can adjust to start delivering oxygen to your muscles at its maximum possible rate. That’s one of the reasons VO2max tests take 10-12 minutes, rather than simply involving a short, all-out sprint. It takes time for the blood flow to your muscles to increase, and for the enzymes that extract oxygen from the blood and oxidize fuel to ramp up their activity levels. A good warm-up gets this ramp-up process over with, allowing your body up to deliver more oxygen to muscles right from the start of the workout or race, and reducing the temporary oxygen debt.

Still, most people warm up with gentle jogging, flexibility drills, and some short sprints. But how about including a six-minute “hard” effort (above lactate threshold but below VO2max pace), about ten minutes before the start of your race or workout? Would that “prime” your oxygen kinetics even more? The challenge is as follows: a sustained burst of hard exercise (above threshold) definitely improves how quickly your body can process oxygen once the actual race starts; this effect can last for a half-hour or more. If you exercise too hard, on the other hand, you deplete your anaerobic energy stores (phosphocreatine), and metabolites build up in your muscles that may slow you down. Numerous experiments over the past decade have found conflicting results: depending on the precise details of the duration, intensity and recovery time following the “priming” burst, performance either increases, decreases, or stays the same.

A new cycling study just posted online at Medicine & Science in Sports & Exercise, from Mark Burnley’s group at Aberystwyth, adds some more data on finding the right balance. They used a six-minute priming bout, 10 minutes before the “race” — a formula that other studies have found to be effective. For intensity, they compared “heavy” (about 25% of the way between threshold and VO2max power) and “severe” (about 63%) priming bouts. The findings: “heavy” priming boosted oxygen kinetics and significantly increased time-to-exhaustion in tests ranging from ~2-10 minutes. “Severe” priming also boosted oxygen kinetics, but didn’t increase time-to-exhaustion, suggesting that the downside of depleted anaerobic reserves outweighed the benefits of more aerobic energy available early in the test.

So what does this mean in practical terms? It’s hard to know how generalizable this protocol is, but I’d say it’s worth experimenting with some sort of extended surge ~10 minutes before the end of your warm-up. If you’re doing a six-minute effort, it looks like you should aim just above your threshold. I know quite a few runners who have incorporated similar but shorter surges of ~1-2 minutes into their warm-up routine. There may be a good argument for runners to stick to shorter surges, since the impact of leg-pounding is a bigger factor than it is in cycling. In that case, you may be able to get away with a higher intensity. But so far I don’t think the research has answered that question — for now, it’s trial and error.

Cyclists: adjusting saddle height and maintaining bone density

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

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Two studies in the March issue of  the Journal of Strength and Conditioning Research that may be of interest to cyclists:

First (and simplest), another study about cyclists and bone density. Lots of previous cross-sectional studies have found that cyclists seem to have lower bone density than non-athletes and people who do impact activities like running. This one, from UC San Diego, actually followed 19 male masters cyclists and 18 matched non-athletes for seven years. Sure enough, the cyclists started with lower bone density, and declined faster during the study. By the end of the study (when both groups had an average age of 57), 17 of the cyclists had osteopenia and six had more serious osteoporosis; in the control group, 11 had osteopenia and one had osteoporosis. The message: get some impact activity, do some strength training, and get your bone density checked periodically.

Second is a study about optimizing saddle height (using “saddle” rather than “seat” makes me snicker, but that’s what they use in the paper, so I’ll stick with it!) for both performance and injury prevention. Apparently there are two standard, well-studied approaches to setting saddle height. The Hamley method, based on research in the 1960s, recommends setting the distance between pedal and saddle as 109% of inseam, measured from ischium (hip bone) to floor. That’s based on optimizing performance. The Holmes method, on the other hand, suggests setting knee angle at the bottom of the stroke to between 25 and 35 degrees to avoid injury.

A useful aside in the paper, derived from the Holmes research: pain in the front of the knee usually means the saddle is too high low, pain in the back of the knee means it’s too low high. [Update March 6: Thanks to commenter Phil for catching the fact that the journal article had it backwards!]

Anyway, the problem is that these two methods don’t always coincide, mainly because people have very different ratios of upper leg to lower leg length. In this study, setting the seat at 109% of inseam led to knee angles ranging from 19 to 44 degrees, and only three of the 11 subjects (who were well-trained cyclists) fell into the 25-35 degree injury reduction zone. So which is best?

The researchers looked at anaerobic power (30 second sprints) and economy (15-minutes at 70% VO2max) for three different settings: 109% inseam, 25 degree knee angle, and 35 degree knee angle. Surprisingly, the 25 degree knee outperformed 35 degrees AND 109%, particularly for economy. These results in well-trained cyclists echoed earlier studies by the same group in casual cyclists. So they conclude that 25 degree knee angle is the best way to set saddle height, since it’s within the “minimize injury” range and also appears to optimize performance. Obviously if you’re a Tour de France racer, you’re going to optimize bike position in a much more sophisticated way, but this seems like a useful rule of thumb for the rest of us.

Crowd support in Delhi

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

***

There were some media stories early on about the lack of crowd support at the Commonwealth Games. I think that was a bit overblown — anyone who’s ever been to the weekday morning qualifying session of a major championship meet knows the crowds can be pretty sparse. I mean, people have jobs! Admittedly, the crowds for the cycling road races today (Sunday) were almost non-existent, because the security perimeter made it virtually impossible to get anywhere near the course! Even with accreditation, it took me ages to get anywhere the start-finish area.

For a true measure of Indian sports crowds, though, I went to the India-Pakistan field hockey match tonight. It was fantastic! Great energy, a friendly guy beside me explained some of the history behind the rivalry, and only a few giant bugs attacked me. Here’s some grainy cell-phone footage that gives some idea of the energy in the stadium:

“Light visors” to beat jet-lag

THANK YOU FOR VISITING SWEATSCIENCE.COM!

As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)

***

Cyclist Tara Whitten has done a lot of travelling over the past few weeks — from the world road race championships in Australia directly to Delhi for the Commonwealth Games, 10 races in less than two weeks. I chatted with her yesterday after she picked up her third bronze medal of these Games, in the individual pursuit, about how she handled the travel.

light-visor

The cycling team — like many other Canadian national teams — has been working with Calgary sleep specialist Charles Samuels, the pre-eminent person in the field. He gave them lots of the standard advice about jet-lag, like getting as much rest as possible on the flight and then focusing on proper cycles of light and dark upon arrival.

She also used melatonin for a few days after arrival. As I mentioned a few weeks ago, I’m trying melatonin for the first time on this trip, which started in Canada, included four nights in London, two weeks in India, and then finishes in Australia. So far I’ve been very happy with it: while I’ve been tired after the flights, I haven’t had any trouble sleeping at night and staying awake during the day. That may simply be because my flights have all had morning arrivals, after which I’ve managed to stay up all day — a good way to reset your clock even without melatonin.

Anyway, the one thing Whitten mentioned that surprised me was that she (and other cyclists, I believe) are using light visors to make sure their bodies get the “daylight” signal loud and clear at the appropriate times of day (first thing in the morning if you’re flying east, late afternoon/early evening if you’re flying west). These things (which, from what I can tell, cost a couple hundred dollars) have been around for years, and are sometimes used for seasonal affective disorder, but it’s the first time I’ve heard an elite athlete mention them.