If you’re wanting to lose weight through running, you're in luck. Running torches through calories at a fast rate – one mile of running will see you burning around 100 calories, depending on your weight and height, and the pace you're running at – and, in doing so, can help you to burn fat.
But it helps if you understand the science. Read on to find out how running can help you to lose weight and burn fat and how to do so safely and effectively.
Calories in vs calories out
To lose weight, you have to burn more calories (units of energy) than you take in, so it’s a good idea to know how many you need in the first place. You can do this by working out your basal metabolic rate (BMR), which is the number of calories you’d need to keep your body ticking over if you were to stay in bed all day.
You can calculate your BMR by using your age, height and weight – there’s a calculator here. Then multiply that figure by 1.55 to account for ‘moderate’ exercise (running three to five days a week) or 1.8 if you're very active – eg exercising for an hour per day at a high intensity. This is how many calories you need to maintain your current weight. You can also use a fitness tracker which will calculate your total daily expenditure.
Aim to create a deficit of no more than 200 calories a day, so you're consuming a little less than you're burning. Reducing your energy intake by any more than this can result in injury, muscle breakdown, fatigue and other health problems caused by low energy availability, including Best wireless headphones.
Once you've done your calculations and know how much food you can roughly consume per day in order to create a calorie imbalance, you should then consider the type of running you're doing. Different sessions will affect the rate at which you burn calories – and how much of that energy is derived from your fat stores.
In the beginning
'For the first six weeks, all you need to do is run,' says sports scientist and coach Ian Mellis. 'As a new runner, exercise floods your body with adrenaline, stimulating the release of fat from your cells, which is broken down by running.'
This means that you will burn fat fast during this first month and a half. However, this golden period won’t last forever. 'Your body soon gets used to this level of stimulus,' says Mellis. 'So after this point it’s useful to start doing intervals and tempo runs a fitness tracker.'
Go long and slow
To begin with, slow low-intensity runs, generally over 30 minutes in duration, are likely to send your body into burning fat stores as fuel rather than carbohydrates. Personal trainer and Polar ambassador Nathalie Lennon says that it'll also depend on the amount of carbohydrates you’ve eaten in the 12-14 hours previously.
'The pace of this run should be one at which you can maintain a full conversation. However, running at such a low intensity for a long period of time, while it may be in the "fat-burning zone", may burn fewer calories than a shorter, higher-intensity run.'
Pass the plateau
As you become fitter, your body will require new stimuli to continue its fat-burning evolution. 'Intervals take your body into the upper echelons of its capacity and increase the amount of oxygen you use to perform and recover, resulting in more calories burned,' says Mellis.
Intervals really come into their own after you’ve finished doing them: the intensity means your body needs more oxygen than normal to return it to its pre-exercise state. For every litre of oxygen consumed, you burn five calories, so as a result, this post-exercise oxygen consumption can elevate your calorie-burning for up to 48 hours.
'Beginners should run at 80 per cent of their maximum effort for one minute, then jog for 30 seconds,' says Mellis. 'Repeat this 20 times and you’ll inhale eight litres more oxygen than if you ran for the same time at a steady pace.'
Perfect combination
For Lennon, the best way to burn fat while running is to combine both high-intensity short runs with longer, lower-intensity relaxed runs. 'The key will be ensuring you take enough rest between your sessions to recover, and also focusing on your diet. If you’re eating more calories than you're burning, you won’t burn any fat regardless of how much running you do. As the saying goes, "You can’t outrun a bad diet."'
Do fasted runs with caution
Lennon advises caution when fasted running. 'I’d only recommend doing fasted running if that's what suits your schedule better. When running fasted, while your body will tap into fat stores as fuel sooner, you'll still be burning the same number of calories as you would be if you did the same run later in the day.'
It all comes down to your total calories in vs out at the end of the day. 'Keep in mind that your body may also tap into protein as a fuel source when training fasted, in other words, your muscle mass,' adds Lennon. 'It’s important to have a high-protein meal to end the day and ensure you eat a high-protein breakfast within 30 minutes of finishing a fasted run.'
Don’t sweat the scales
When you start running you’re not only burning calories, you’re also building muscle, which weighs more than the fat you’re burning. 'It’s surprisingly common to gain weight when you start running,' says personal trainer Kim Ingleby. 'This is partly because muscle is denser than the fat it replaces, and partly because the training makes you crave a higher ratio of carbs to protein in your diet.'
As a result, keep an eye on how many carbs you eat after a run – researchers at Louisiana State University found that aerobic exercisers often eat more than their daily calorie allowance in the misplaced belief that they need to ‘refuel’ after training.
Do strength training
The two main dangers when running to burn fat are muscle-mass loss and injury risk. 'To prevent loss of muscle mass, as well as reducing the risk of injury, it’s important to do strength training alongside your runs,' says Lennon. 'Having a stronger body will only benefit your running while decreasing your risk of injury.'
Don’t over-fuel
Remember, you want your body to burn off excess fat, not just the sports drink you’ve knocked back. Some sports drinks contain a surprisingly high number of calories, so save these types of drinks for longer runs.
'Beginners need to train for over 30 minutes before thinking about sports drinks and gels,' says Harley Street sports nutritionist Drew Price.
Time your refuelling
The importance of timing your post-run meal will depend on the amount of time you spent running. For example, if you ran for 20 minutes in the evening versus two hours, it'll be more important following the long-distance run to get a recovery snack or meal soon afterwards (ideally within 30 minutes).
'The best choice of fuel is a combination of protein and carbohydrates,' says Lennon. 'Both are critical for recovery. Try to hold off on high-fat foods until after your first post-run snack or meal, as when our body works to break down fat, this can slow the digestion of protein and carbs. We want them to be digested quickly so that they can get to work to aid our recovery.'
