Training, explained
Strength training vs cardio: what burns more, and what matters more
Cardio burns more calories. For a 65 kg woman, an hour of strength training at a normal gym pace burns about 230 kcal, against about 310 kcal for brisk walking, 440 kcal on an exercise bike and 555 kcal running at 12-minute miles. But strength training has a different job: it keeps and builds your muscle, and that matters more with every year, and every diet.
Burn more calories in an hour, and build your heart, lungs and stamina.
Burns less, but builds and protects the muscle that keeps you strong, steady and you.
Why the calorie number isn't the whole story
If you only judged exercise by calories, you'd never lift anything. But the scale only tells you how much you've lost, not what.
When you eat less to lose weight, up to 40% of what you lose can be lean mass, muscle included. That's the part you want to keep: it's what lets you carry the shopping, get up off the floor and stay strong into later life.
A review of the research on keeping muscle while losing weight (Cava, Yeat and Mittendorfer, Advances in Nutrition, 2017) found that both endurance and resistance exercise help preserve muscle mass during weight loss, and that resistance exercise also improves strength. So cardio helps, but strength training does something cardio can't.
Lose the fat, keep the strength. That's the whole point of training while you lose weight.
Strength training for women: what it does that cardio can't
- Keeps muscle while you lose fat. Strength work tells your body the muscle is still needed, even when you're eating less.
- Builds strength you use every day. Stairs, lifting a suitcase, getting up from a low chair.
- Gets more important with age. Muscle tends to decline as we get older, and strength training is one of the best-supported ways to hold on to it, before, during and after menopause.
- Doesn't need a gym. Squats to a chair, lunges, press-ups against a wall or kitchen counter and resistance bands at home all count.
And no, it won't make you bulky. Building a lot of muscle takes years of hard, deliberate training and eating to gain weight. For most women, lifting means stronger and firmer, not bigger.
Your hour, side by side
Put in your weight to see roughly what an hour of each burns. Nothing is sent anywhere.
Strength trainingCardio and BJJ
Strength training vs cardio: calories burned in 60 minutes
Find your weight across the top. Each number is roughly what an hour burns, in kilocalories (kcal).
| 60 minutes of | 55 kg | 65 kg | 75 kg | 90 kg |
|---|---|---|---|---|
| Strength workout at home (body weight)Compendium code 02056 · 3.0 METs | 165 | 195 | 225 | 270 |
| Strength training, normal gym paceCompendium code 02054 · 3.5 METs | 195 | 230 | 265 | 315 |
| Brisk walking, 3.5 to 3.9 mphCompendium code 17200 · 4.8 METs | 265 | 310 | 360 | 430 |
| Strength training, hard and heavyCompendium code 02050 · 6.0 METs | 330 | 390 | 450 | 540 |
| Exercise bike, steadyCompendium code 01200 · 6.8 METs | 375 | 440 | 510 | 610 |
| BJJ class (40 min drilling, 20 min sparring)Compendium codes 15425 and 15430 | 385 | 455 | 525 | 625 |
| Running, 12-minute miles (8 km/h)Compendium code 12030 · 8.5 METs | 470 | 555 | 640 | 765 |
| BJJ sparring, the full hourCompendium code 15430 · 10.3 METs | 565 | 670 | 775 | 925 |
MET values and codes from the 2024 Adult Compendium of Physical Activities. The BJJ class adds 40 minutes of drilling (5.3 METs) to 20 minutes of sparring (10.3 METs).
Why strength training burns less
Most of a strength session is rest. You lift for 30 to 60 seconds, then rest for a minute or two so the next set counts. That rest is the point, not wasted time. Shorter rests and heavier work push the number up: a hard session is about 390 kcal at 65 kg, nearly double a normal one.
Where cardio and BJJ come in
Cardio is brilliant for your heart and lungs, and it burns more. Walking is the easiest place to start, and an exercise bike or a gentle run builds fitness fast.
Brazilian jiu-jitsu, a grappling martial art with a fast-growing number of women's classes, is one of the biggest burners in the table: a 60-minute class is about 455 kcal at 65 kg, and an hour of hard sparring about 670 kcal. It builds strength and fitness at the same time. If you're curious about learning jiu-jitsu, JitsAI is a BJJ training app from Turtle's co-founder, Scott Flear.
A week that does both
The UK Chief Medical Officers' guidelines for adults are a good shape for the week: 150 minutes of moderate activity, like brisk walking, or 75 minutes of vigorous activity, plus activities that build strength on at least two days.
- Two strength sessions of 20 to 45 minutes, at home or in the gym.
- Walking most days, building up your steps a little at a time.
- One thing you love that gets you out of breath: a class, a swim, a run, or the mat.
Pair it with enough protein, because muscle needs both the training and the building blocks.
On Mounjaro, Wegovy or another GLP-1?
On a GLP-1, appetite drops and weight can come off quickly. That makes strength training and protein more important, not less, because they are the main habits linked to protecting muscle while the fat comes off. Read how Turtle helps protect muscle on a GLP-1. This isn't medical advice: if you feel weak, dizzy, very tired or unwell, talk to your prescriber, GP or pharmacist. If it feels urgent, call NHS 111.
How the numbers are worked out
Every calorie figure here uses one simple sum: MET × body weight in kg × hours.
A MET compares an activity with sitting still. One MET is roughly 1 kcal per kg of body weight per hour. So an hour of strength training at 3.5 METs for a 65 kg woman is 3.5 × 65 × 1 = 227.5, which we round to 230 kcal.
The MET values come from the 2024 Adult Compendium of Physical Activities (Herrmann and colleagues, Journal of Sport and Health Science, 2024), the standard reference researchers use. They're averages for adults, so treat them as estimates: your real number can be higher or lower, and how hard you work and how long you rest change it a lot.
Fitness watches aren't more exact. In a Stanford study of seven wrist-worn devices, none estimated calories to within 20% (Shcherbina and colleagues, Journal of Personalized Medicine, 2017), and many people find their watch reads high, especially for strength training, where your heart rate climbs while you barely move.
Logging it in Turtle
Open Train, tap Log a workout, then choose Strength workout to build your sets and exercises, or pick a quick activity type for a walk, a run or a class. Turtle can also pull in workouts from your watch through Apple Health or Health Connect. Your training feeds your LeanShield™ muscle-protection score. Step-by-step: log a workout manually and build a strength workout.
Slow and steady, for good
Train for the muscle, not just the calories
Turtle is the women's health coach: strength workouts, food tracking with protein built in, and LeanShield™ to show whether you're protecting your muscle. 4.6★ on the App Store · 100,000+ women.
Questions women ask
Does strength training or cardio burn more calories?
Cardio, minute for minute. For a 65 kg woman, an hour of strength training at a normal gym pace burns about 230 kcal, against about 310 kcal for brisk walking, 440 kcal on an exercise bike and 555 kcal running at 12-minute miles. These are estimates from the 2024 Adult Compendium of Physical Activities.
Is strength training or cardio better for losing weight?
For the number on the scale, both help a little, and what you eat matters most. For what you lose, strength training matters more: when you eat less, some of the weight that comes off can be muscle, and strength work is one of the best ways to keep it. Most women do best with both.
How many calories does an hour of strength training burn for a woman?
It depends mostly on your weight and how long you rest. At 65 kg, a normal gym session is about 230 kcal an hour, a hard, heavy session with short rests about 390 kcal, and a body-weight workout at home about 195 kcal.
Will lifting weights make me bulky?
Very unlikely. Building a lot of muscle takes years of hard, deliberate training and eating to gain weight. For most women, strength training makes them stronger and firmer, and helps them keep the muscle they have.
How many calories does BJJ burn for women?
At 65 kg, a 60-minute BJJ class with drilling first and sparring at the end is about 455 kcal, and an hour of hard sparring about 670 kcal. Lighter women burn a little less and heavier women a little more.
Is my watch right about calories?
Treat it as a rough guide. In a Stanford study of seven wrist-worn devices, none estimated calories to within 20% (Shcherbina and colleagues, Journal of Personalized Medicine, 2017). Strength training is especially hard for a watch to read.
Educational only, not medical advice. It isn't tailored to you and doesn't replace advice from your GP, prescriber or a qualified professional. If you're pregnant, have a health condition or haven't exercised for a while, check with your GP before starting a new exercise plan. Calorie figures are estimates. Mounjaro® is a registered trademark of Eli Lilly and Company, and Wegovy® of Novo Nordisk; Turtle Method isn't affiliated with or endorsed by either company. LeanShield™ is a trademark of ParrotPal Ltd: it rates the habits linked to protecting muscle, is not a medical device and doesn't measure muscle.