Can you lose weight just by exercising?
Is it possible to drop the pounds without reducing your calorie intake? We investigate how much exercise it takes to make a difference.
We’re fond of food and expect the same goes for you. Even if you cook plenty of healthy recipes, it’s likely your diet gives you more calories than you would need for a sedentary lifestyle.
Calories are incorporated into the body in various ways, depending on the nutritional content of your food. Carbohydrates give us glucose, while protein builds muscle and fats become body fat. Sometimes, we get too much of these good things.
Exercise is one way to use up a surplus, especially of fat and carbs. For those of us who enjoy working out, this is a more appetising prospect than cutting out a favourite foodstuff.
The average person burns about 400 calories in one hour of gentle jogging, which is the energy equivalent of about five chocolate biscuits. Clearly, the more exercise you do, the fewer treats you’ll need to cut out in order to maintain a healthy weight.
To find out whether you can really lose weight through exercise alone, we spoke to experts Beth Furness, a nutritionist with Nutracheck, and Rory Coleman, a running coach and founder of Coleman Coaching.
Which are the best exercises for weight loss?
Different types of exercise affect the body in various ways, so if your goal is weight loss, you should plan your workouts specifically.
Exercises that are proven to help with weight loss include:
- Long-distance running
- Cycling
- Swimming
- Skipping
- Dance (especially high-energy forms such as Zumba)
“The best exercise you can do is Nordic skiing, which is the best calorie burner at 1,100 calories per hour,” adds Coleman.
Of course, there are other important benefits to exercise. Your workout goals could also include building muscle, developing flexibility, reducing stress and improving athletic performance.
When you’ve chosen your weight-loss exercise activities, plan them into your week. You’ll need to do enough exercise to offset your calorie intake – probably at least 30 minutes per day, on average.
5 expert tips to boost the weight-loss effect of your workout
1. Stay in the ‘fat burn’ zone
The body uses different resources for fuel, depending on the intensity of exercise.
“For weight loss, we want you in the fat-burning zone,” says Coleman.
“If your heart rate is below 75% of the maximum, you’re using oxygen and body fat as fuel. If you go into the next zone up – with your heart working at 75-80% – you’re using 35% glycogen and 65% fat, so you’re burning less fat.”
To do the calculations, find out your maximum heart rate in beats per minute by subtracting your age from 220 (or get a more accurate measure via a test). Then, plan your exercise regimen around activities that keep your heart rate between 50% and 70% of your maximum.
When we phoned Coleman for his advice, he’d just burned 4,000 calories running a marathon among the sand dunes near his home. “People tend to go for a run and run too fast, but if you really want to lose weight, it’s all about slow, long-distance running,” he advises.
2. Plan a sustainable exercise regimen
When you exercise intensely – especially after a period of low exertion – there’s a heightened risk of injury or extreme fatigue, both of which can stop weight loss in its tracks. It’s far safer to plan a moderate regimen that you can sustain long-term.
“Health guidelines suggest aiming for at least 150 minutes of moderate-intensity activity each week, which works out to around 30 minutes on most days,” says Nutracheck’s Beth Furness.
“This type of movement should get your heart rate up, make you breathe a little faster and warm you up. Even a brisk walk or gentle bike ride can count towards your activity levels. The most important thing is to find activities you enjoy and can stick with consistently.”
3. Incorporate some strength training
Body strength probably isn’t the first factor you’d consider when planning for weight loss, but building some muscle plays an important role.
“Strength training helps maintain muscle mass, which is crucial for supporting your metabolism,” Furness explains.
People who have a high proportion of muscle in their body composition tend to metabolise food more efficiently than those with a high proportion of body fat. The higher your ratio of muscle to fat, the more easily you’ll use up those excess calories.
Popular forms of strength training include resistance training (whether using gym equipment or a resistance band), circuit training and CrossFit.
However, the more muscle you build, the less weight loss will be shown on your scales, as muscle does weigh more than fat.
4. Stick to healthy eating (and avoid undereating)
Focusing on exercise doesn’t give you carte blanche to eat whatever you like, however. “Also aim to prioritise whole, nutrient-dense foods where possible, such as lean proteins, healthy fats and fibre-rich carbohydrates, which can help you feel satisfied while supporting muscle recovery and overall energy levels,” says Furness.
And, even though your calorie intake should be lower than the amount of calories burned through exercise (or just keeping your body functioning) to lose weight, undereating during an exercise programme can lead to problems.
“It’s important to be mindful of your intake and ensure you’re not eating too little or allowing your net calorie intake to drop too low as a result of exercise,” says Furness.
“If your body isn’t receiving enough fuel, this can lead to fatigue and nutrient deficiencies, and even slow down your metabolism over time. Eating a few additional calories back after exercising will help to avoid dropping your net intake too low.”
5. Consider trying fasted exercise
Some studies have shown that we burn more fat when we exercise on an empty stomach. This tactic is called ‘fasted exercise’.
We wouldn’t recommend fasted exercise to everyone, especially not those who are pushing their bodies harder than usual with vigorous activity. However, it seems that for some people, this tip could speed up weight loss in the short term.
What to do when you plateau
For many people, losing weight is not a linear journey.
“Weight loss is often a series of stops and starts, and progress can fluctuate from week to week due to a variety of factors like hormones, water retention, sleep patterns and diet,” says Furness.
“A true plateau occurs when, despite consistently following your plan, the scale hasn’t shown any downward trend over several weeks.”
Adjusting non-exercise factors such as sleep and diet might help you resume weight loss when you reach a plateau. However, it’s also worth assessing the overall effects of your exercise regimen on your health and fitness. If you’re feeling great at your plateau weight, then the best bet might be to tweak your targets.
“Increased exercise can lead to a bigger appetite, which might result in eating a little more without realising it, naturally balancing out the extra calories burned,” says Furness.
“Strength training in particular can affect what you see on the scales. If you’re gaining muscle (which is fantastic for overall health and metabolism), it can sometimes make it seem like weight loss has stalled, as muscle is denser than fat.
“However, this doesn’t mean you’re not making progress! Your body composition could be improving, even if the number on the scale stays the same.”
Furness suggests looking at how your clothes fit, your energy levels and improvements in strength as alternative measures of progress.
So, can I lose weight just by exercising?
It’s possible to lose weight through exercise alone, provided you burn more calories than you consume.
However, if you’re not paying any attention to your diet, it becomes hard to predict whether exercise will use up enough calories to help you lose weight. Usually, the key to weight loss is striking an effective balance between calorie cutting and exercise.
“Diet plays the biggest role in losing weight, as it’s much easier to reduce calorie intake than to burn large amounts through exercise alone,” says Furness.
“That being said, exercise should not be overlooked. While it’s not essential for weight loss, it offers many benefits that can support long-term success.
“Cardiovascular exercise contributes to overall calorie expenditure and improves heart health. Exercise can also help regulate appetite and improve energy levels and mood, all of which can make sticking to a healthy diet easier,” she says.
Coleman agrees that diet is ultimately the most important factor in a weight loss plan.
“Exercise helps lose weight, but the best thing to do is upgrade your lifestyle, and activities like running are part of that change,” he says.
“What you need is a personal system upgrade, factoring in the types of food you eat, alcohol intake, emotional eating, and how many times per day they eat.
“If I can make people accountable for their food while doing some exercise, funnily enough they lose weight – as much as 20% in three months.”
Further reading:
How many calories should I eat?
How many calories to lose weight?
How many calories will I burn?
What are the best exercises to burn fat?
Top 5 health benefits of exercise
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