Coach’s Blog #21 – The Myth of SFR

There is a 2012 YouTube clip that shows Ivan Basso riding up the Vorterra – a 9.8 km climb averaging 4.6% – just outside Tuscany, clad in his Liquigas winter gear. He is stuck in the saddle at less than 50 rpm, pushing a massive gear and rarely getting up out of the saddle. What the heck is he doing?

Basso is performing an SFR (slow frequency revolutions) workout, an aerobic strength training workout believed to build leg strength and overall cycling efficiency. Cycling lore says that Basso’s SFR workouts consisted of 8 reps of 3 minutes at 380 Watts and 45 rpm, or 115% of FTP – that’s an incredibly low cadence, especially at such a high power output, even for such an experienced rider. My knees hurt just thinking about that.

Despite his incredible successes, recent research shows that Basso’s SFR workouts have no real scientific basis. Countless coaches, riders, and programs have endorsed the benefits of SFR’s over the years: increased leg strength, aerobic capacity, cycling performance, and pedaling efficiency.

But while the practice makes sense, at least in theory, there is currently no scientific evidence that low cadence intervals, ‘big-gear,’ or ‘on-the-bike strength work’ will make you a faster cyclist (Hansen and Rønnestad, 2017). In fact, many studies have shown that performing intervals of the same intensity and duration, but at a freely chosen cadence instead, are “beneficial for performance and physiological adaptations.” (Kristoffersen, et al. 2014)

If anything, riding at low cadences can do more harm than good. Cadences below 70 rpm, and especially below 50 rpm, place a high amount of torque on the muscles and joints of the lower body. The knees, in particular, are in a high-risk position, as any tiny imbalances in bike fit or pedal stroke can quickly manifest into a serious overuse injury.

But where did the myth of low cadence training come from?

In the old days, cyclists didn’t go to the gym to lift weights. In fact, most cyclists nowadays don’t either. But the trend is shifting, and in the positive direction too. As more and more cyclists hit the gym, they are realizing the benefits of strength training through increased their overall strength and flexibility, improved their cycling efficiency, and prevention of chronic injuries.

The logic behind SFR intervals: you push harder on the pedals, therefore you’re legs get stronger. But evidence has been sparse. While some studies cite increased muscular strength and overall cycling efficiency as a result of SFR intervals, these improvements have been shown to be no more significant than in the control group, i.e. performing intervals at freely chosen cadences.

The science isn’t all bad, however, as one New Zealand study found support for low cadence interval training (Paton et al. 2009). However, this study consisted of only 18 total participants and contained no control group. While the differences between the low-cadence and high-cadence groups was significant, even the authors admitted that there may be more at play than the training alone, stating that, in regard to the differences in mean maximal oxygen uptake, “differences for other physiologic indices were unclear. Correlations between changes in performance and physiology were also unclear.”

Why Don’t SFR Intervals Work?

Cycling is a lot more complicated than just pushing hard on the pedals. In order to be fast, you need to produce a high Watts/kg for a long period of time, but you also you need to be smart, efficient, tactically savvy, and psychologically strong. While SFR intervals may improve your power output at 50 rpm, science has yet to prove that they would improve your ability to sprint, time trial, climb, or attack.

Pedaling slow only makes you better at one thing: pedaling slow.

As with all sports-specific training, the most successful athletes are also the best all-rounders. There is not just one thing that makes Peter Sagan great, there are many: speed, positioning, peak power, 30-second power, pedaling efficiency, cardiovascular efficiency, team support, and sport psychology, just to name a few. It is the same with recent Tour de France champions Egan Bernal and Geraint Thomas. They are good at climbing – perhaps even pushing low cadences on the steep bits – but they are also good at time trials, long and hilly stages, and riding in crosswinds.

The Ideal Cadence for Cycling

Findings suggest that there is no ideal cadence for cycling. Sorry that’s probably not the answer you wanted to hear. But, research does suggest that ideal cadence varies between individuals, so finding your ideal cadence may be easier than you think. In fact, you probably already know it.

When you go out and enjoy the perfect ride, when your head gets lost in the clouds and time just seems to fly by, what was your average cadence? When you were pedaling comfortably on the flat or up a gradual grade, you weren’t even thinking about your cadence, because it was comfortable, it came naturally to you. In that moment, how fast/slow were you pedaling? That is yourideal cadence.

Your ideal cadence works for you, and that’s all that matters. When your coach prescribes a “high-cadence intervals” session, ask them what number(s) you should shoot for. What is defined as ‘high cadence’ will vary greatly between individuals. For a novice rider in their 60s, holding 100 rpm could be considered high-cadence; for an experienced track rider, perhaps a goal of 190+ rpm is more suitable – 100 rpm is their warm-up pace, after all.

Off the Bike Strength Training

Weight lifting – and other forms of strength training such as power lifting, circuit training, and plyometrics – is safer and more effective that SFR training when it comes to improving muscular force. These structured gym workouts better isolate certain muscle groups without doing damage to others, and come with less risk for chronic injury as with doing SFR intervals on the bike.

In summary: unless the year is 1963 and you’re riding a Heylett Speciale up Alpe d’huez in the 45-tooth “little ring”…there’s no need to practice riding at 50 rpm.

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Sources

Effects of Cycling Training at Imposed Low Cadences: A Systematic Review (Hansen and Rønnestad, 2017)

Low cadence interval training at moderate intensity does not improve cycling performance in highly trained veteran cyclists (Kristoffersen et al. 2014)

Effects of low- vs. high-cadence interval training on cycling performance (Paton et al. 2009)

1963 Heylett Speciale