Steve Trew on turbo training – part 1

Mass turbo trainer session

Steve Trew, as well as being our official link with triathlon’s Golden Years, is also a fine coach and we asked him to dust off some of his notes about turbo trainers and useful sessions. Prepare to suffer because, on a turbo, there’s no place to hide…


We are not always blessed with the greatest of weather in Great Britain, and although the majority of triathletes will far prefer to go outside in all but the most inclement weather there are occasions when it is safer to train on the cycle indoors. One advantage of the turbo trainer is that there can be no distractions when doing a quality, interval based training session.

And, despite what you may be told, turbo training isn’t just for the Winter months. There are lots of occasions when you need to do a hard workout but have limited time available and that is when the turbo can really come into its own. Indeed, just like you can always make use of a swimming pool for extra sessions even when you’re swimming open water the turbo is always there to squeeze in that extra bit of quality training.

The technology of turbo trainers has improved immensely over the last few years; it is possible to pay many hundreds of pounds for a state of the art model which measures everything that can be measured. At the other end of the spectrum, you can pay as little as £50 for a perfectly adequate model. The more expensive models will, of course, have the ‘extras’; speed, power output, cadence, calories burned, extra resistance (hills – a very worthwhile add-on) and even ‘live’ video of real races to ride along with. As with most things, you get what you pay for but don’t go out and buy the most expensive model just because you think you should, it’s often not worth it and you may never make best use of it.

A turbo trainer is a valuable training tool, use it sensibly and it will pay dividends. A big advantage of using the turbo is that it is easy to monitor progression in training. Over time you should be able to see that your fitness has improved by directly comparing the amount of effort used either in terms of a decreased heart rate or in terms of an increased power output. Using a heart rate monitor is a method of self-measuring in progression; as fitness improves, the heart rate will be lower at a corresponding effort and improvement is immediately seen.

If you don’t have a heart rate monitor, then you need to understand that each stage is a progression from the previous stage. Improvements are initiated in either time, repetitions, resistance or time of each individual repetition. Each stage may last a week or a month depending on the individual capability and standard of each triathlete. The starting point for the process will depend on individual fitness and the sessions set out in each stage should be completed before progressing to the next stage.

A word about gears

With such a huge range of gear setups available these days it is almost impossible to predict what will be on any given bike; 9-speed, 10-speed, compact, etc. However, what really matters is the fact that you can change the gears to make yourself work harder or easier against a given resistance setting on the turbo.

In order to make sense of the sessions that I will be presenting here, and in the coming weeks, I need to explain a few basics so, if you understand all this already please bear with me.

The front chain rings are the ones that are driven round by the pedals – the whole assembly is often called the ‘chainset’ – and for a road bike these will typically be supplied in either a 39 tooth inner ring and a 53 tooth outer ring (sometimes you get 42 teeth on the inner and 53 on the outer) or, if you are using a ‘compact’ chainset there will typically be 34 teeth on the inner ring and 50 on the outer. For the purposes of the sessions that follow I will describe these as the inner (or smaller) ring and the outer (or bigger) ring. In practical terms you’ll regard the inner ring as your ‘easy’ and your outer ring as your ‘hard’ efforts.

At the back of the bike there is a cluster of smaller rings, the whole thing is generally referred to as a ‘cassette’ and the individual rings are called ‘sprockets’. These transfer the chain’s driving power to the rear axle and, just to confuse you, the smaller the number of teeth on the sprocket the harder the effort will be (and, potentially, the faster you will be going). The cassette typically will have around 11 or 12 teeth on the smallest sprocket and, for a road cassette, anything from 23 to 27 teeth on the largest sprocket. Depending on the manufacturer, and the rider’s ability/road conditions it’s going to be used on, you could have an 11:21, 12:23, 12:25, 12:27 or any number of other combinations.

Given that you could have either 9-speed or 10-speed on your bike (or, perhaps, even 8-speed…) you can see that the number of possible combinations is pretty much infinite! This doesn’t help at all when you’re trying to set out a turbo programme…

So, we have to make a compromise and that means that we ignore the biggest and the smallest sprockets on a 9-speed and the two biggest and the smallest on a 10-speed. This tends to give us a pretty consistent set of gearing because the large differences are usually at the top end anyway and what you’ll have is something very close to 13 : 14 : 15 : 16 : 17 : 18 : 20 which allows us to achieve progressive steps in effort.

Monitoring yourself

It is important when training using a heart rate monitor that calculations are based on reality i.e. make sure that you know the figures you are working with. Knowing your actual maximum heart (MHR) rate and resting heart rate (RHR) are essential. One method for finding MHR by using a turbo trainer is outlined here, alternatively a ‘flat out’ 10 or 25 mile time trial should leave you at MHR.

Here are two methods for testing MHR on a turbo trainer. The first assumes a very basic mode while the second assumes that you have some form of power output reading available. Note that it is much better if you can have a friend or coach to monitor this test with you, whichever procedure you use.

Note. This test is extremely demanding and exhausting. Do not attempt it if you are unwell or very unfit and if you feel giddy, nauseous or unwell during the test then STOP!!

Self test 1

  1. Warm up until heart rate (HR) is constant.
  2. Go into big ring and bottom (easiest) gear (eg 53 x 22), and pedal at 95 rpm for 2 minutes.
    Note HR at beginning and end of the 2 minutes.
  3. Progress up through the gears every 2 minutes. Note HR at beginning and end of every 2 minutes.
  4. Eventually the HR will level out after having risen constantly (although not necessarily consistently) throughout the test.
  5. This is probably not max HR, carry on by getting out of the saddle and pedalling as hard as you can until exhaustion (this is where you need that friend or coach)
  6. Note down max HR as accurately as possible.
  7. Warm down (spin) in easy gear and note HR recovery by recording every 2 minutes.

Self test 2

  1. Warm up until heart rate (HR) is constant.
  2. Set and monitor power output at…  …what exactly? Individuals differ so much that it really is difficult to give guidelines which will be appropriate for all athletes. Let us say about half to two thirds of what you believe is your maximum; for the purposes of this example the workload is 150 watts. Note your HR.
  3. Increase the wattage load by 20 every four minutes (Opinions differ on the preferred time for each increase but the point is that the increase should be regular and consistent). Note your HR throughout, as before.
  4. Continue until exhaustion.
  5. Note down max HR as accurately as possible.
  6. Warm down (spin) in easy gear and note HR recovery as before.
Time 0 – 4 4 – 8 8 – 12 12 – 16 16 – 20 20 – 24
Watts 150 170 190 210 230 250+
Blood lactate (mmol/l) 1.18 1.32 2.01 2.35 3.49 10.2
HR 147 155 161 168 173 191
VO2 (l/min) 2.08 2.28 2.53 2.74 3.04 4.25
VO2 (ml/kg/min) 28.5 31.0 34.3 37.3 41.3 57.8

The table shows a full set of test results (this was done in a lab with all the extra equipment for lactate testing and measuring oxygen uptake) from an 18 year-old female with a personal best 25 mile time of just outside one hour. With the wealth of information provided by this test, we were able to formulate a training schedule which made best use of her strengths and attempted to address her weaknesses. Her fractional utilisation of VO2 max was approximately 65%, VO2 max 57, and max HR 191 bpm. For her cycling we used HR zones of 140-150 for base endurance and 165-170 for her threshold work. This very basic outline paid dividends with a shift upwards in fitness, an increase in fractional utilisation and a significant improvement in times over 10, 25 and 50 miles.

Coming up next

That’s probably enough to get you confused with for one week so I’ll just leave you with one session to whet your appetite for the next two instalments. As with the MHR tests above, all training sessions presuppose a warm up before, and warm down at the end of the hard work phase.

Session one: lactate tolerance

This is a ‘classic’ session which every triathlon and cycling coach I know gives to his/her athletes; it is close to a time trial on the roads. It requires great concentration from the athlete and closely relates to a race situation.

  1. Warm up steadily to 80% – 85% of MHR.
  2. Hold this % for 40 minutes with a cadence of between 90 and 110. You will almost certainly need to change gears to maintain this heart rate.