Reading Research: Maximal Strength Training Improves Cycling Economy

So far in my research reviews, I have limited myself to discussions of articles relating to the stress series I ran and then the series on sports psychology I have just finished.

However, ultimately, this site is about the best ways to go about getting stronger.  So since I’m just coming to the end of a series of cycling book reviews, what better study to look at than one investigating the effects of strength training on endurance cycling?

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What’s the study, then?  And why are we looking at it?

The study is called Maximal strength training improves cycling economy in competitive cyclists, by Sunde, Støren, Bjerkaas, Larsen and Hoff, Journal of Strength and Conditioning, 24.

I am keen to bring research like this to the attention of as many people as I can find.  While the strength and conditioning community (particularly in the US) is very much aware of this kind of idea and makes extensive use of it, your average endurance athlete (particularly in the UK) still believes that strength training is counter-productive to their goals.

You would be amazed at the kind of comments that I still see on UK cycling forums, where people will argue until they are blue in the face that adding in squats and deadlifts to their winter training will make zero difference to their racing performance come the following summer.  To me that just sounds like an allergy to hard work.

Two words: Chris Hoy.

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OK, let’s move on.  What’s the background?

By way of background, let’s start with the idea that endurance performance in road cycling is almost entirely dependent on aerobic respiration.  However, that doesn’t mean that the only factor that is important in building a great endurance athlete is developing a high VO2-max.  There are in fact three major factors, which are:

• Maximal oxygen consumption - VO2-max,
• Lactate threshold, and
• Cycling economy

Cycling economy can be defined as the steady-rate oxygen cost of a standard power output.  It’s kind of a measure of the efficiency of the cyclist as a mechanical system.  You put fuel in one end in the form of food and oxygen and cycling performance comes out of the other end.

Another similar measure is called “work efficiency”.  This is the ratio of performance to fuel, often treated as just oxygen.  It’s pretty much the same thing, really.

This study sets out to look at whether strength training can improve cycling economy (and work efficiency), without affecting maximal oxygen consumption.

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Now let’s look at the study

The purpose of the study

The purpose of the study was to investigate the effect of maximal strength training on:

• maximal strength,
• cycling economy,
• work efficiency, and
• time to exhaustion at maximal aerobic power.

The method

Sixteen competitive road cyclists were randomly assigned into either an intervention or a control group.  The intervention group performed half-squats, 4 sets of 4 repetitions maximum, three times per week for eight weeks, as a supplement to their normal endurance training.  The control group continued their normal endurance training during the same period.

What happened?

The intervention group manifested significant improvements as follows:

• maximal strength (14.2%),
• cycling economy (4.8%),
• work efficiency (4.7%), and
• time to exhaustion at pre-intervention maximal aerobic power (17.2%)

The authors noted that no changes were found in VO2-max or body weight in the intervention group.

The control group exhibited improvements as follows:

• maximal strength (none)
• cycling economy (none)
• work efficiency (1.4%)
• time to exhaustion at pre- intervention maximal aerobic power (none)

The only significant improvement was in work efficiency but this improvement was significantly smaller than that in the intervention group.

So what do the researchers conclude?

They conclude that maximal strength training for eight weeks improved cycling economy, efficiency and increased time to exhaustion at maximal aerobic power among competitive road cyclists.

So what are their recommendations for racing cyclists?

The researchers therefore advise cyclists to include maximal strength training in their training programs.

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My thoughts

While I welcome this study and am a big fan of this kind of open-minded thinking, practically speaking, I think that there are some limitations to this study.  The main two being:

• the cyclists were not previously weight-trained, i.e. they were beginners, and
• the protocol was 4 sets of 4 reps of half-squats, 3 times a week for 20 minutes per session.

While I don’t think that another set/rep protocol would have had a better response for beginners, I do think that to continue to get results they would have to tweak the volume up a little and increase the amount of time that the training sessions took. This increase in volume and time would then start to impact adversely on their other training modalities.

It would therefore be interesting to see where the point of no further benefit was reached.  I don’t really know what half-squats translate to in real squats but is the strength level a 1.5x bodyweight full squat?  Is it a 2.0x bodyweight full squat?  I don’t know but it would be interesting to find out at what point the increased training time/workload and bodyweight started to have a detrimental effect on performance.

A useful benchmark might be that Chris Hoy, as a track cyclist, has a maximal full squat of 227.5kg at a bodyweight of 93kg.  That’s 2.45x bodyweight but then he is a sprinter.  Still, it goes to show what is possible.

And on the subject of the half-squat vs. the full squat, I suspect that the lack of involvement of the glutes in the half-squat would lead to sub-optimal results.  It would be interesting to see whether a similar study done with full squats would have achieved better results.