Training Tips
Carbs are a limited resource, so burn fewer of them
Carbs are a limited resource, so burn fewer of them
We hope you’ve picked a few goal events for the coming season. After all, there is no better way to stay motivated to train than by having a target or two. Whether your event is a gran fondo, gravel race or charity ride, if you want to have a good day out on the bike, you’ll need to make sure you are fuelling yourself properly.
The intensity at which you ride is linked with the type of fuel – fat or carbohydrates – used to produce that effort. In the past, insights into a rider’s fuelling requirements were only possible with an expensive metabolic machine. Now with software, such as the inscyd system used extensively in the pro peloton and more and more for amateurs, we can get a breakdown of fuelling requirements a little more easily.
What is important to keep in mind is that 1 g of fat contains 9 calories, and that our fat stores are practically unlimited. On the other hand, 1 g of carbohydrate contains 4 calories. We can store 20 g of carbohydrate per 1 kg of lean muscle mass. Fat is a high-yield resource that is always available, while carbohydrates have a lower yield with a limited burn time.
Having implemented the inscyd testing at The Cycling Gym, one thing we’ve noticed is that no one is fuelling adequately for rides. Even at the lowest endurance intensities, we are seeing carbohydrate needs of 50 g/h. Based on our experience, most people are probably ingesting around 25–40 g/h, at most. This figure means that they are not even meeting their endurance energy needs. Now take that intensity up toward your tempo zone, where you will likely spend a great deal of time at any sort of goal event, and your energy needs are likely up in the range of our maximum carbohydrate intake limit of 90 g/h.
Doing your best performance means riding your key event at the maximum intensity you can manage without running out of energy. When we say running out of energy, we really mean running out of carbohydrates. We tend to run out of carbohydrates because, for most of us, it is the primary fuel source. As we mentioned, it’s limited. Let’s look at an example of the fuelling requirements of a rider from our gym who competed at the 2019 Whistler Granfondo. You’ll see it isn’t possible to fuel enough to replace the energy being used.
The rider, who came in 75th, covered the fondo distance of 121 km in three hours and 31 minutes. His normalized power was 290 W. His power profile for the ride was 3.5 W/kg. From our testing, we determined that the rider’s carbohydrate needs were 864 g or 246 g/h. But is that a target he could hit?
The highest range of potential carbohydrate intake for a cyclist is between 70–90 g/h. Let’s suppose the rider had a generous carbohydrate intake of 90 g/h. Even with this rate, the rider still has a deficit of 548 g for the event, which is more than the total carbohydrates of 442 g in his system and available to him at the start of the race. This deficit fits with how the rider felt. He said he had felt spent with about 10 km left on the day as he ran out of sugar.
The harder you go, the more carbohydrates you use to fuel your ride. (The Carbohydrate Combustion chart shows how the rate increases with your power.) But if you can’t possibly take in enough carbs, how can you ride at intensity for longer periods of time? How can you train to perform at your key event?
Since carbohydrates are a limited fuel source, and since you’re unable to replace it quickly enough, you should aim to maximize your fat burning capabilities. Remember, fat – even in a lean athlete – is in great supply. You want your body burning as much fat as possible. Put another way, on the Carbohydrate Combustion chart, you want to see that line move to the right – illustrating less reliance on carbohydrates as you increase intensity. One way to achieve this change is to train your tempo ability by increasing the amount of long intervals you do below 84 per cent of maximum heart rate. If your tempo ability is strong, then you are likely in a decent fat-burning place.
What we see repeatedly with new clients is that most have no tempo ability. Popular training programs and philosophies tend to focus almost solely on threshold training, working at levels higher than tempo and turning everyone into sugar burners. Take the time to reassess your training. Make sure you are putting in the training time at the endurance and tempo levels to improve your fat-burning abilities. Then, you’ll really go far.