Weights and Cardio. Both have risen and fallen in popularity over the last few decades – but which is more effective? Personally, I like lifting, there’s nothing more satisfying than bicep curling a huge Kitkat Chunky up towards your mouth – it’s incredibly rewarding.
My own preferences aside, I looked into the science and did a little number crunching to give you an insight into our methods at The Better Body Group, and to attempt to answer a long-debated topic in the fitness industry.
Before the question is addressed, it’s important to know and understand that fat loss comes from a negative energy balance, otherwise known as a calorie deficit. Neither cardio nor weight training possess any magical properties to burn more fat than the other. So, in the context of fat loss, it would make sense to be more concerned about the number of calories burned in the session.
However, it would be short-sighted of us to look at a single workout and choose the mode of exercise that burns the most calories. If we delve into some of the pros and cons to both modes of exercise, we might see the favour shift when we start thinking long-term.
Weighing up the pros and cons
Breaking this information down, the real question is – would you rather try and wrestle a bear or outrun it? Staying on track, the biggest factor supporting cardio is the greater number of calories burned. The biggest factor supporting weight training is the increased metabolic rate and more toned physique following fat loss.
Cardio
Pros
• Burns more calories/hour than lifting weights
• Can be done more often than lifting weights (faster recovery)
• Adaptable intensity when you’re short on time (eg 15mins high intensity/1+hour lower intensity)
Cons
• Too much can interfere with strength and muscle growth; thus reducing the effectiveness of your weight training
• Too much can cause muscle wastage; thus reducing your metabolic rate
• To burn a significant amount of calories – it’s hard work
Weight training
Pros
• Promotes fat-free mass; thus increasing/ maintaining your metabolic rate long-term.
• Results in a more ‘toned’ physique following fat loss
• Still effective at burning calories
Cons
• Doesn’t burn as many calories as cardio
• Needs more recovery time between sessions.
• Less likely to outrun a bear
Scaling their significance
1) How significant is the difference in calories burned in a 1 hour cardio session?
Typically if an individual burns 600-700 calories in an hour of cardio, they are likely to burn about 400-500 calories in an hour of lifting weights. Approximately a 200 calorie difference.
200 calories isn’t bad, but when you put it into context of how many times per week that you train, you might be able to earn yourself two or three beers by the end of the week. So, would you rather increase your efforts in the gym for a small return on your calories? Or would you rather just replace a few beers with a few slimline gin and tonics instead? Which is the easier option?
Another thing to note – studies have shown that after high intensity cardio sessions, the body tries to conserve energy by moving less. Throughout the rest of the day, subconsciously you’re likely to sit down more, fidget less, and become more efficient with your movement to burn less calories as an instinctual response to survive until the next meal.
This means that your total energy expenditure by the end of the day might just be the same as if you didn’t go to the gym at all! Not a great trade deal if you ask me.
If you enjoy cardio then that’s great! It is likely to have a positive yet modest impact on your fat loss. Do what you love to do. But it might be worth taking an online mental evaluation test, there might be something wrong with you.
2) How significant is the is the difference in metabolic rate from weight training?
Unfortunately, there aren’t many long-term studies that exist. The practical implications of conducting such studies is very difficult. However, what we do know is that our basal metabolic rate (BMR, A.K.A. your metabolism) is associated with our fat-free body mass. It is essential to attempt to maintain or build muscle mass when dieting.
Studies have also shown that with prolonged bouts of dieting, resting metabolic rate can decline from up to 30%, which is the body’s way of fighting to maintain a set point for body weight. It further decreases as we age too! But weight training can mitigate this. A cardio-only approach will likely cause more muscle wastage, which is the opposite of what we want to achieve.
To reap the benefits of weight training, you also don’t have to train every day of the week. 3x/week is sufficient for most. The relative effort you have to put into weight training is also low compared to cardio when fat loss is concerned.
Conclusion
The most important factor when exercising is ultimately adherence. Every trainer at the Better Body Group understands this, and will always put your enjoyment and preferences first.
If you hate what you are doing and can’t sustain it, then you will lack consistency. Without consistency, trying to get results is futile.
That being said, from a fat loss perspective, the only role cardio plays is burning calories. The relative effort you have to put into cardio to induce extra fat loss is incredibly high, and you could get comparable results by either eating a little less, or being a little more active from day to day which requires very little effort.
The calories burned lifting weights is also accompanied by adaptations to improve our metabolism (targeting the biggest variable in our daily calorie expenditure), for greater long-term fat loss benefits.
Plus you never know when you might need to wrestle a bear!
by Sam Austin, Head of Young Athlete Development at The Better Body Group
