By Ric Stern
VO2max, nice little acronym, bandied around all the time in cycling circles. You’ve probably seen GCN mention it, and most likely every cycling magazine you’ve ever read. But what is it, what does it mean, and more importantly than the physiology if it’s so important, can you improve it?
In reverse order, as that’s the way that I roll:
Yes, yes you can improve it, at any age and at nearly all fitness levels.
It’s the volume of oxygen that can be taken up and used by the body, maximally.
The limiting factor in endurance exercise (that’s any exercise lasting more than 90 seconds, yes, 90 seconds!!) is the amount of O2 that can be utilized to provide energy for the mitochondria within your cells. This is rate-limited by your VO2max: that is, you can “operate” at various percentages of VO2max depending on the duration you’re exercising for. Of course, this isn’t to say fatigue doesn’t occur from other sources (energy availability, mental tenacity, and so on), because it does, but VO2max is the top-of-the-chain limiter.
To actually measure your VO2max, you’d need apparatus to collect your “expired respiratory gases” and measure the concentration of O2 and CO2 you breathed out, which obviously requires specialist equipment. In lieu of that, maximal aerobic power (MAP) — the power at the final stage of a ramp test to exhaustion — can be used as a proxy for VO2max. Such a test tells you the power you can produce at VO2max, and from that data you can accurately back-calculate VO2max itself. The calculator at cyclecoach.com/rbr does this for you.
The science bit (skip this if you want to know how to improve VO2max rather than understand it)
The respiratory chain works like this. We take in air via the mouth and nose (though the nose alone does not provide sufficient intake, even at low intensity), and air moves down into the lungs, where O2 is extracted via pulmonary diffusion across the alveoli sacs and bound loosely with hemoglobin in the blood to form oxyhemoglobin.
Blood is pumped around the body by the heart, and as exercise intensity increases, both your heart rate and your “stroke volume” increase. Heart rate needs no explanation — we can see it climbing on our watches and computers (it’s a proxy for intensity). Stroke volume can be thought of as the amount of blood ejected per beat.
The analogy is a sink in your bathroom: the tap being turned on or off is your heart rate, the amount of water that comes out in each “on” is your stroke volume, and the total amount of water collected in the sink is your cardiac output. At rest your cardiac output might be 5 L/min; during extreme maximal exercise it could rise to 30 or 40 L/min in elite endurance athletes.
That rise in cardiac output means more blood and oxygen is transported to the vital organs and, during exercise, to the working muscles (your legs), for cycling. (Blood goes everywhere, of course, but the harder you work, the more is directed to the muscles in demand, with minimal amounts elsewhere.) As it reaches the muscles, the O2 is “unloaded” to the mitochondria to fuel muscle contraction via ATP synthesis.
How important is VO2max?
As we’ve seen, VO2max sets the upper limit of what’s sustainable. Well-trained athletes can hold around 90% of VO2max for roughly an hour. Both the percentage you can sustain and how long you can sustain it for can be trained as can, for most people, VO2max itself.
It’s also worth noting that VO2max appears to be an excellent indicator for all-cause mortality, to which it’s inversely related. In other words, the higher your VO2max, the less likely you are to succumb to some sort of fatal disease. This isn’t just about going faster; it’s about aging better.
What’s a good VO2max?
VO2max varies with fitness level and sex. Females are typically around 15% lower than an equivalent-ability male, due to lower hemoglobin and blood volume.
Clinically, a VO2max above 60 mL/kg/min in either sex is considered elite, while around 45 mL/kg/min would be normal for a young male in his 20s who doesn’t exercise much. Research on elite military personnel such as the SAS or the Marines shows values in the upper 40s mL/kg/min, while elite male endurance athletes are above 70. Male Tour de France winners sit in the upper 80s to low 90s mL/kg/min and the highest accurately recorded human VO2max is 94 mL/kg/min.
The bit you actually want to read (jump to this if you’re short on time!)
Many different sessions of similar intensity can help you improve VO2max.
Warm up for 15 to 20 minutes (longer if you have the time) at a reasonable endurance pace, with 2–3 × 30 seconds at FTP and a couple of minutes between these brief spikes. Then ride easy for 5 minutes.
Session 1: The Classic
5 × 4 minutes at 115–125% of FTP. Cadence 80+, seated or standing, I like to do these up a hill. The 115–125% range is wide and depends on your individual physiology. Technically, you could pace these as the highest effort you can maintain across the 4 minutes, and across all the intervals, without dropping power. Cool down for 10 to 30 minutes.
Session 2: Heart Stretcher
This one’s a “fast start” effort: you ride harder than the power at VO2max for 90 seconds, settle to an easier effort (your heart rate stays elevated), then gradually ramp the effort back up. Great fun.
- 90 seconds at 115–145% of FTP (the effort you choose depends on your own physiology hard enough that you can barely maintain it)
- 2 min 30 at ~90% of FTP
- 2 min at 100% of FTP
- 2 min at 110 – 115% of FTP
- 8 minutes easy
Repeat 1 to 3 more times.
Session 3: 30:15 (or 30:30)
2 sets of 13 × 30:15 (or, if you’re like me and can’t quite manage that, 30:30). Hit the 30 seconds at around 100% of MAP (the power from the final 60 seconds of a ramp test to exhaustion), and the 15 or 30 seconds at around 50% of FTP. 10 minutes between sets. Enjoy!
Session 4: The Hills
Using a hill that’s around 3 minutes long: 5–8 efforts at the maximum you can maintain during and across the intervals. In other words, don’t start interval 1 at 300 W and finish it at 200 W. Aim for a power that’s just sustainable (say 270 W in this example), or around 115–130% of FTP. If interval 1 averages 270 W, the second 250 W, and the third 240 W, you’ve gone too hard at the start.
Conclusion
Training at efforts around the power that elicits VO2max brings both performance and health benefits. Depending on your current fitness, you could see a 5–20% increase in this power, and a similar uplift in your FTP.
The training is hard, so it’s always worth checking with a medical doctor whether it’s something you should be doing. Age itself isn’t a barrier, but ill-health could be. (For what it’s worth, there’s evidence of increased VO2max in a rider who was 100 years old. You’re almost certainly not too old for this.)
So how do you actually put this into practice?
These sessions all aim to have you exercising at around your MAP the average power from the final minute of a ramp test to exhaustion, and the intensity that drives VO2max up. Once you know your MAP, our calculator at cyclecoach.com/rbr turns it into your full set of training numbers, including your FTP (which, for most riders, lands at around 72–77% of MAP).
And if you’d rather these sessions came as a proper progressive plan fitted around the hours you’ve actually got rather than guessed at, that’s exactly what our new Bronze coaching does. It’s brand new. Normally Bronze riders are looked after by one of my coaching team, but while I iron out all the moving parts I’m taking on the first three myself. So if you’d like me coaching you directly, now’s the moment.
Find your MAP and start at cyclecoach.com/rbr.
Ric Stern is founder of CycleCoach and has coached athletes to World Championship gold, Commonwealth medals, and Paralympic podiums across 29 years.
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