Performance Q&AThe big cycling questions answered by our team of expert coaches, nutritionists and riders
01 WHAT’S THE SECRET BEHIND NEW YEAR WEIGHT LOSS?
You’re a few weeks into 2024 and your plans for a faster, lighter you have hit a wall. “Why am I not edging closer to racing weight?” you lament. “What am I doing wrong?” Well, you might not be doing anything wrong. You might just need a little patience, plus a dollop of reality. “It sounds simple but losing weight is all about creating an energy deficit,” says Dr Adam Collins, associate professor of nutrition at the University of Surrey. “It’s about fewer calories in and more calories out. Of course, we know it’s not that easy in practice.”
Weight loss isn’t an exact science but, roughly, a pound of fat contains around 3,500 calories. “Cool,” you ponder. “I know from my watch that I burn 500 calories an hour on most rides. I’ll just pop out for seven hours and I’ll lose a pound of fat.”
Of course, there are gaps here. This approach, beyond burying your immune system and leaving you a moody mess, doesn’t account for factors like general feeding, on-the-bike fuelling and intensity of exercise. Still, there’s good fatty news when it comes to that latter point, which can often become a zonal sea of confusion…
Fat-burning intensities
At rest and at low intensities of exercise, we burn predominantly fat for fuel. As intensity increases, the body’s increasingly reliant on carbohydrates to fuel the working muscles. It’s why all of us have a FatMax zone, which is the optimum fat-burning intensity. This is generally accepted as around 70-75% maximum heart rate for trained athletes and 60-65% max HR for less-fit athletes. “Your muscle becomes adapted to exercise because it’s under metabolic stress and running out of fuel,” says Collins. “It adapts by increasing blood supply, the number of [energy-producing] mitochondria, and improving the ability to break down fat and glucose more efficiently.”
This metabolic stress happens with low-intensity, long-endurance exercise, but it’s not the be all and end all when it comes to fat. “It can also happen through higher-intensity exercise,” says Collins. “This might not initially oxidise high levels of fat; instead, you’ll be burning through carbohydrate and creatine phosphate. But that energy crisis you’ve created needs to be paid back. How you do that is switching to more aerobic system
