Time trials are a great test of physical and mental strength, and one of the events where training with an SRM system can give you a real advantage. You can fine tune your training as well as your race performance.

The most important thing to keep in mind is that time trials are different - each course has its own demands, and each rider has their own strengths and weaknesses. If you're targeting a specific event, you'll need to know what the course is like and train for that, because general preparation will only get you so far. For instance, Kristen Armstrong won the 2008 Olympic Games in Beijing in August, and placed 5th at the World Championships in September - was she tired from the long season, or was it just that the Worlds course didn't suit her as well, or even that she'd trained so specifically for the Olympic course that the fitness didn't transfer? Fifth in the world is still a great result, but it highlights the effect that small differences can make.

If you're training for a time trial, the first thing you'll need to do is do some field tests with your SRM on flat terrain (unless you're doing a mountain time trial, then do the tests on a mountain) to find out how much power you can sustain for a few different durations; for instance 5 minutes, 10 minutes, and 30 minutes. You don't need to be able to ride for 5 or 6 hours like road racers, you just need to be able to sustain a power just under your threshold for the duration of the race. So, you need to find out what that power is for you over different durations. Repeat each test a few times in the space of a couple of weeks, so make sure that you're getting a good, repeatable result to work with.

Keep in mind that when we talk about "threshold" powers, we're not just talking about one number that you might get from a lab test. We're talking about the highest power that you can maintain for a given time without blowing up. You'll know from experience that you can hold a higher power if you only need to ride at that pace for 4 minutes, rather than 20 minutes, for instance. You wouldn't ride an hour long time trial at the same pace that you'd ride a short prologue. It's about finding out how far into the red you can go and still maintain your performance for whatever amount of time.

So, having said that, if you're aiming at a time trial that should take about 30 minutes, on a flat course, how would you train for it? You'd take a look at the power you found you could in the field tests for 30 minutes, and you'd design your training around that. For instance, if you could hold 300W maximum, you would aim to increase that number slowly by doing efforts slightly above it (say, between 330-350) interrupted by a couple of minutes slightly below it (roughly 260-280). When you ride slightly above your threshold, you start to build up acid in your muscles and your bloodstream from your anaerobic energy system, and then when you ‘recover' (not total recovery) just below your threshold your body learns to get rid of this acid more quickly. If you let yourself rest completely between the harder efforts, you wouldn't get the training response that you're looking for.

The goal of the training should be to increase the power that you can maintain for the necessary time, not to increase your maximum power output. The carefully paced training efforts are great preparation for race day, when pacing becomes a vital component of success. Even a minor error in pacing at the beginning of the race can have a massive impact on overall performance.

In big races, it's easy to get excited at the start and go just a little bit harder than you planned to... it happens to the best of them, even at World and Olympic level. The problem is that even if you only go 10W over your threshold for the first lap or portion of the course, you are engaging your anaerobic energy system and building up acid. This can end up making you reduce your effort in the final lap or section of the course by as much as 50W, meaning that your overall average for the race is much lower than what you could have maintained if you'd paced the race more evenly from the start. This is why a number of Pro riders use their SRMs in the most important Time Trial events, because they can keep an eye on their power and make sure their pacing their effort as they planned, based on the information they gained about their capabilities during training.

Here is a file of an excellently paced time trial, by Adam Hansen at the 2008 World Championships. He started off with a solid effort, and then held a very steady pace throughout the rest of the race. His average powers for the following 10 minute blocks were 394W, 397W, 402W, 390W, and 398W, all very similar which shows that he had a good idea of what average power he was aiming to hold. His heart rate response shows us that the effort was sustainable for him, as his average heart rate for those same 10 minute blocks was 181bpm, 178bpm, 179bpm, 183bpm, and 183bpm - if his heart rate had kept increasing throughout the effort, it would have showed us that he'd gone into the red, but since his heart rate remained stable it shows us that he paced the effort well. His cadence throughout the bulk of the race (after his starting effort) was around 100rpm, and again the stability of his cadence data shows us that he paced his race intentionally, and used his SRM to maintain his desired pace within a very tight margin.