So the first thing to consider is how long it might take you to get up there. Most club cyclists will be in the range of 50 - 75 minutes (this is assuming you are going for the best time i.e. flat out). 50 minutes or less would be a Cat A or Cat 1 cyclist who excels on the hills, and 75 minutes for a recreational, but fit club cyclist who rides regularly but is not that keen on the uphill stuff! If you are not a club cyclist or a regular rider, and you just want to get up the mountain (and are not worried about the time), then my best advice to you is to get as many hours in the saddle as possible before you arrive here.
If you know your threshold power (see definition below) you can guess a time using the power calculator at the bottom of our Alpe D’Huez page and adjust the time until you get to your threshold power.
Once you have an idea of the time it might take you (and a rough estimate is fine for this), you need to work on maximising your effort or other words power output for that duration. For most people this will be the same as trying to increase their threshold power, as threshold power is generally defined as ‘the power you can maintain for one hour’. There is a lot of information available on this (try searching for ‘improve threshold power’ or ‘increase threshold power’ etc), however as with any tricky question, you’ll probably find a number of different answers!
I’m a level 3 cycling coach, and have ridden up Alpe d’Huez many times & what has worked best for me is interval training (this is assuming that you already have a good level of fitness and you are not a newcomer to cycling). As anyone riding up Alpe D’Huez will be putting in a long steady effort, shorter intervals will not really help that much. I tend to find that 6 - 8 minute intervals are long enough that you are working your top end aerobic systems hard.
If you have not done interval training before, then I’d again suggest you do a little research, but the principle is that you work as hard as you can for the defined interval duration, then rest and repeat. By resting for a sufficient amount of time you allow yourself to maintain the high effort levels during the intervals. Once you find that you are not able to maintain the same power (your perceived exertion should get higher each time) then it’s time to stop. If you don’t have a power meter then seeing how far you can repeatedly get up a climb in a fixed time works just as well. Once you just can’t get up to that road sign in a certain time any more despite you very best effort, it’s time to head home for a well deserved rest!
In addition to the interval training, once you have developed a good level of fitness, consider occasionally adding a maximum effort ride over the time you expect to take to ride up Alpe D’Huez. However be warned that this is a very tough session so only do this when well rested and allow for a few easy days afterwards (of course this is all relative to your current training load, and your ability to recover from hard efforts). As well as being a great workout, it will be excellent practice for you to be able to judge your effort when it comes to the real thing.
Get your pacing right and it will make a big difference on your time. For most people, the tendency will be to go off too hard, so make sure you relax at the start and keep some in reserve, as it’s a long climb!
In addition to this, to in order to maintain the same power output as your body gets tired, you’ll need to put in a greater perceived effort (and your heart rate will rise for the same effort over time too due to cardiac drift). All this points towards a gradual increase of effort all the way up. So the intervals should help you gain strength and the longer efforts get your body ready for the test up Alpe D’Huez.
If you’d like to discuss any aspect of riding in the Alps or any training considerations please don’t hesitate to contact me - as a coach and keen cyclist I enjoy nothing more than these types of conversations!