Ask the Experts - Legs running out of power

Ask the Experts - Legs running out of power

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Knowledge Level: Beginner

Peter recently got in touch wondering why his legs keep on failing him in the final fifth of his sportive events.

Q: “I’m new to sportive riding and I have trouble in the latter stages of 40-mile events I’ve been riding. I get to about 32 miles and I’m left with no power in my legs even on the flat.”

A: We’d look at the following key areas to try and identify where your problem lies but it’s possible it might well be a combination of all four.


Have you been training consistently, correctly and for long enough? If you’re new to cycling, our Beginner’s Training Plan allowed 25 weeks to prepare for a 100 km (60 mile) sportive and typically scheduled in 3-4 rides per week. Although your sportives have been slightly shorter, this is the sort of timescale and amount of training you should have put in. It’s also important that your training has been planned, structured and at the correct intensity. You should have factored in regular easier recovery weeks and been using a heart rate monitor and a bike computer showing cadence. If your training has been more hit and miss, this could easily be a reason for your failing legs. A good idea to get you quickly up to speed and into a structured plan would be to follow our 7-week panic plan. However, if you’re keen to progress your cycling next year, following one of our full plans over the winter would be our recommendation.


Are you setting off too fast? Learning to pace your rides correctly and monitor intensity is something you learn in training. We strongly recommend all riders to invest in a heart rate monitor, test for their Functional Threshold Heart rate (FTHR), use this to set training zones and then use these zones to pace your training rides and sportives. In general, most flat and downhill sections should be ridden in Zone 1-2 with Zone 4, where your FTHR lies, used as a “red-line” limit on climbs. Spend too much time in Zone 4 or above and you’ll soon accumulate significant fatigue in your legs which you’ll pay for later on in the ride.


Are you eating and drinking enough to fuel your ride? The key is to eat little, early, often and not to wait until you’re hungry. On rides longer than 90 minutes, it’s essential to start taking food on from 20-30 minutes in. You’re not eating for that particular moment but 10-15 miles down the road. Again, your fuelling strategy is something you should have practiced numerous times in training. Pacing and fuelling are also intrinsically linked as, if you’re riding too hard, you won’t be able to process the food you’re taking on.


Are you using your gears correctly and maintaining an optimal cadence? Many novice riders try to push too hard a gear and turn their legs over far too slowly. This can result in your legs fatiguing prematurely. Use a bike computer with a cadence sensor and, on the flat, aim for a cadence of 90-100 RPM. On steep hills this may drop but you should still aim for 80 RPM+. Are you comfortable riding in a group and working with other riders? If you’re riding entire sportives on your own, you’re making your life far more difficult than it needs to be. Sat closely behind another rider, you can save to 30% of your energy. Groups may well fragment on climbs but you should always be on the look out for a group to ride with or at least a few other riders to work with when you get back on the flat. If you’re not sure about the skills and etiquette of riding in a group, you should consider joining your local club and you should also look at our group riding content.


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