RUNNING ON EMPTY

ARE THE SUPPOSED WEIGHT-LOSS AND ENDURANCE BENEFITS OF NOT MUNCHING BEFORE WE MOVE JUST EMPTY PROMISES?

- CHLOE GRAY

For some it's down to logistics - getting up early enough to digest a fuelling breakfast before an early run is a challenge. For others, it's a considered choice - heading out with the fuel tanks empty, we've been told, forces the body to turn to fat as a fuel source, boosting endurance and burning off unwanted wobble. Or does it?

The latest research suggests that forgoing that pre-run bagel might not be the boon you think it is. A recent study found motivation and energy levels before exercise were lower when participants were in a fasted state, while those doing fasted workouts performed worse and enjoyed workouts less than their fed peers. It's the latest study to challenge the value of exercising on an empty stomach; in fact, researchers have long been questioning this received wisdom.

FAST AND THE CURIOUS

First, let's be clear on the meanings. "Being 'fed' refers to your metabolic state after eating food, when the body is digesting and absorbing the nutrients," explains Renee McGregor, leading sports dietitian and RW columnist. She notes that this state typically lasts for up to four hours after eating, although it could last for up to six, depending on the speed of your metabolism and what you've eaten - high-fat or fibrous food, such as whole grains, red meat and seeds, will take longer to digest than simple carbohydrates.

As such, when you wake up in the morning after an (ideally) eight-hour slumber, you're probably in the opposite state: fasted. "What you eat the night before will always influence your energy the following day, but it won't be available as direct fuel because your body will have broken it down and used it for energy," adds McGregor, dispelling the myth that a bowl of pasta at 7pm will have fully carbo-loaded you for a morning outing.