The topic of weights vs cardio has been an age-old debate, with the common misconception that lifting weights will make you big and bulky and excessive cardio will cause you to lose both fat and muscle. Yet, neither of these points are 100% true and there’s a simple reason for it. Keen to find out more about weights and cardio, and which is better for fat loss? Let’s break it down!
So, what’s the science behind weight loss?
In simple terms, your body is a machine that uses fuel, like a car. Instead of burning petrol, our body burns food as a source of energy, which is measured in calories. While many factors can contribute to either weight loss or weight gain, the science behind what determines body weight generally remains the same:
- If you eat more calories than you burn, you will store it as fat, resulting in weight gain.
- If you burn more calories than you eat, you will start to burn your stored fat, resulting in weight loss.
While many people prefer to reduce calories strictly through dieting, the healthiest and most sustainable way is to combine a healthy diet, cardio and weight training.
Love hitting the pavement for a morning run or stretching your legs on the bike after work? Whatever your go-to form of cardio is, guess what? The results are in: cardio is the calorie-burning king!
So, what is cardiovascular training (cardio)? It’s essentially any activity that raises your heart rate and keeps it elevated throughout the activity. So, technically, vigorously vacuuming your room could be classed as cardio, but the more traditional forms of cardio training incorporate activities such as jogging, rowing, swimming and cycling. Cardio is great for strengthening your heart, lungs and increasing your body’s metabolism.
When it comes to exercise and weight loss, research confirms that per session, you will burn more calories during a cardio session, compared to weight training for roughly the same amount of effort. For instance, if you weigh 73kg, you may burn approximately 250 calories per 30 minutes of jogging at a moderate pace. However, if you trained weights for the same amount of time, you are likely to only burn around 130-220 calories during that session.
How is cardio beneficial for weight loss?
- You can burn more calories during one session - During cardio, your heart rate is elevated, your blood is pumping faster, you’re breathing heavier and you’re no doubt sweating up a storm - which is a fair indicator that you’re burning calories. The harder you work and longer you train, you’ll ultimately be rewarded for it by burning more calories.
- It’s easy to adjust the intensity of your workout - Whether you’re running on the treadmill, cycling, mountain climbing or swimming, it’s easy to change the intensity of your cardio routine by simply running faster, changing the bike gears, increasing the incline, or swimming quicker to accelerate your metabolism and boost your calorie burn even more.
- You can do cardio more frequently - After an intense weight session, let’s be honest, your muscles are a little sore and require rest to recover and repair. However, as cardio is less strenuous on the body, you can essentially do a cardio routine most days of the week without the impact.
What cardio exercises should you be doing to maximise my results?
Bad news: There’s no ‘one size fits all’ approach to cardio, which means there’s no universal ‘best cardio’ exercise. Good news: There are some great forms of cardio, which will do more to get you closer to your goal, including:
- Low-impact exercises - Slower results, easier on the body. Low-impact exercises, such as cycling, elliptical machine and pilates, will burn fewer calories but can have great results if done consistently. This form of cardio is ideal for those with injury, joint pain/problems, or for those wanting to improve their balance and alignment.
- High-impact exercises - Faster results, harder on the body. Higher impact exercises, such as sprinting, burpees or jumping, will burn more calories in comparison to low-impact activities. If you’re just new to cardio and don’t have the stamina to perform a high-intensity workout, start by incorporating just a few high-intensity exercises into your routine.
- Consistency - Whether your go-to form of cardio falls into low-impact or high-impact, the most important part of any routine is consistency.
How frequently should you do cardio?
Just like any form of exercise, the frequency of the workouts will depend entirely on your fitness level and the time you’re willing to set aside for fitness. Here are the general guidelines for cardio frequency:
- Health - Incorporate moderate-intensity cardio for 30 minutes per day, five days a week.
- Weight maintenance - Try adding about 150 to 300 minutes of moderate-intensity activity per week.
- Weight loss - Try adding more than 300 minutes of moderate-intensity exercise per week.
Just when you thought you had the answer to fat loss and were ready to fill your workout schedule entirely with cardio...think again. Plot twist: Although cardio may burn more calories per session, weight training will continue to burn calories even after you’ve completed your workout. Yep, you read that correctly - you can continue burning fat from the comfort of your couch after completing a weight session!
So, what is weight training? Sometimes referred to as resistance training, weight training is the process of lifting weights (i.e. exposing your body to resistance) so that your muscles are forced to adapt to the stress and grow.
Weight training is great for building muscle and achieving a leaner and more toned physique. It helps with bone density, boosts metabolism and increases the amount of testosterone produced by your body (which benefits mood, mental alertness and energy levels). However, contrary to popular belief, weight training alone will not give you the bulky appearance that many women fear. Achieving that sort of look requires lifting extremely heavy, and having the diet to match it.
How much fat can you burn during resistance training? There’s no definitive answer to this question as it’s based on your size and age. For instance, the more muscle you have, the higher your basal metabolic rate (BMR), which also means the higher the number of calories your body will burn while resting. However, to put it into perspective: Roughly 450g of muscle may burn anywhere from 7-13 calories during 24 hours, whereas the equivalent weight in fat will only burn somewhere between 2-5 calories over the same period.
Why is weight training beneficial for fat loss?
- Post-training calorie burn - Unlike cardio, weight training allows you to continue burning calories long after your workout. Why? Well, after each strength workout, your muscles require energy to repair the damaged muscle fibres.
- It helps to reshape your body - Weight training isn’t just useful for burning fat, it also completely changes your body composition as you’re simultaneously toning your muscles.
- You won’t burn muscle - When paired with the appropriate diet and supplementation regime, resistance training will allow you to lose strictly body fat, whereas cardio may help you to lose weight, but it will likely be a combination of fat and muscle.
But, what’s best for fat loss?
*Drum roll* BOTH! Both forms of training are highly beneficial in their own ways. Cardio helps with building up the strength of your heart and lungs, and weight training will help to build more lean muscle mass. Strictly speaking, you’re going to be able to burn off more calories in a cardio session than a weights session. However, the point that most people miss, is that cardio and weight training are tools that you can use together to benefit your overall health. The number one rule to losing weight is maintaining a caloric deficit, whereby you’re consuming fewer calories than you burn. As such, combining both weight training and cardio with a healthy diet, will not only allow you to lose fat but to achieve your desired body composition too!