7 THINGS YOU DON’T ALREADY KNOW ABOUT GLYCOGEN
Yeah, yeah, it’s stored glucose (sugar) and carbohydrate your muscles use to make energy. Here’s what you might not realise about this precious fuel resource, according to Iñigo San Millán, PhD, director of the Exercise Physiology and Human Performance Laboratory in Boulder, Colorado.
You burn at least 1 gram a minute while riding – at low intensities. At race pace, you’ll need to triple that.
You’ve got 400 to 500 grams fully stocked. That’s about 8400 kilojoules’ worth. Eat 30 to 60 grams of carbs an hour – two PVM Energy Bars – on rides of more than three hours to stay fuelled.
It stores with water. You stash 90ml water with every 30g glycogen, which is why you may gain 1 to 2 kilograms during a taper.
Fit riders have bigger fuel tanks. Trained muscles can hold about 32 grams of glycogen per 100g of muscle tissue. The same untrained muscle holds just 13 grams. Muscles misfire without it.
Glycogen regulates muscle calcium function, which you need for muscle contraction. When levels decline, so does power output.
Recovery = prime storage.
Damaged muscles don’t store glycogen well. Failing to rest can cause you to tap into your protein stores to fuel efforts, leading to overtraining and poor performance.
You might be depleted.
San Millán’s lab found that about 30 per cent of competitive cyclists had suboptimal glycogen stores. If you’re riding more than an hour a day, get about 5.5 to 9 daily grams of carbs per kilogram of body weight.