An exercise session first thing in the morning can be tough; not least because it often requires waking up far earlier than you'd have liked to. But it can also be hard-going due to a lack of food - and therefore energy - in your system.
There's an eternal debate over whether or not it's a good idea to work out on an empty stomach. Does it really mean you burn more fat? Or could it actually just end up reducing your metabolism? We spoke to a sports dietitian to get all the answers.
"There can be some benefits exercising on an empty stomach, but it is very individual and goal dependant," Alexandra Cook, The Sports Dietitian, who's working in partnership with nutritional supplement brand Lift, told Cosmopolitan.
Here's the major pro of exercising after fasting: "As we sleep, our stored carbohydrate (glycogen) naturally depletes, a bit like a tank of petrol reducing. If you exercise as soon as you get up without eating, you would have to rely on fat stores a lot sooner than if you had readily available energy to use from breakfast," explains Alexandra.
And that's not the only plus, according to the expert. "There is evidence that, over time, fasted training can produce cellular adaptations in the muscles that can benefit endurance capacity."
So you'll burn fat quicker and eventually be able to work out for longer? I'm sold.
But it's not quite as simple as that. The Sports Dietitian notes that it's advisable to follow some extra steps if you're going to work out on an empty stomach, in order to gain benefits and to stay healthy and well. Here are the two rules you should swear by:
1. Eat a high carb and high protein meal after a fasted workout
"It is really important to follow up fasted sessions with a high carbohydrate and high protein meal," says Alexandra, because "the body requires extra nutrients post exercise to enable training adaptations to occur."
2. Don't work out on an empty stomach too often
"You should not train fasted more than twice a week, and fasted training is only appropriate for low intensity exercise," the dietitian urges. "Anything that is high intensity or working at a high heart rate should be fuelled well before hand."
Those are the rules; stick to 'em.
Alexandra Cook, aka The Sports Dietitian, is a registered clinical and sports dietitian with 13 years of experience in dietary management.