Does Cardio Help you Lose Weight?

We’ve all heard it: “Gotta do your cardio!” I used to believe that too—spending hours sweating on the treadmill, chasing calorie burn in the hopes of shedding pounds. But here's the truth… it didn’t work. And honestly? It just made me exhausted and hungry.

Now I can promise you, that if you follow my advice, you can achieve your fitness goals and gain another 8 free hours this week. Yup. Eight hours wide open to spend doing something fun!

In today’s episode, we’re busting the cardio myth wide open. I’ll walk you through the real science of how your body burns energy, why excessive cardio can actually backfire—especially for midlife women—and what to do instead to protect your strength, your time, and your sanity.

If you’re sick of being told to “just move more” to lose weight, this episode is for you.

Let’s reset your relationship with movement—starting now.

Welcome to episode 19 of the Midlife Reset Podcast. I’m Cheryl Gordon Yoga Therapist. I’m on a mission to educate midlife women on how to lose weight, sleep better and feel stronger using the tools of yoga and mindfulness.

Here’s the science around cardio exercise.

Energy in and energy out works for nuclear fusion or basic electricity. But we are humans. Our system is dynamic and brilliant and considers so many complex variables that it can never be as simple as calories in and calories out. And even with mechanical things like the gas mileage on your car. It’s never exactly as advertised because there is temperature, terrain, wind, and so many variables. Your bodies are infinitely more complicated than a car.

The body is designed to be ultra efficient. The first few moments of a brisk walk, run, cycle or stair climb taxes the system as it rushes to cope with the changing load. Soon, the body compensates and shifts to maximize efficiency. For most of human existence, we have had a shortage of food. We have evolved to conserve calories at all cost. And we’re very good at making these adjustments quickly.

In fact, in episode #2 of this podcast, my colleague Sharlene Styles explained the Total Daily Energy Expenditure calculation really well. This makes it all so clear why blowing it out with cardio exercise is just not necessary to lose weight. I’ll put the link to episode #2 in the show notes. Briefly, about 70% of the calories you will burn today will be based on your Basal Metabolic Rate. This is the energy your body needs to just lie around and breathe. (Spoiler alert: we’ll talk more in a few minutes, but this is why your personal trainer is going on and on about building muscle… muscle requires more calories just to lay around than other tissue). Then you burn another 10% of your calories just processing the food you eat. So 80% of the calories you’ll burn today are just about surviving. No treadmills yet. The next 15% of the calories you’ll burn is in movement… just normal going up and down the stairs to do laundry… walking the dog… cooking dinner, etc. That’s a lot right? And finally, 5% will be related to specific exercise activities. Even elite athletes still break down to this basic percentage.

Why wouldn’t we burn a bunch more calories if we really “blew it out”? Because your body has evolved to be that super efficient machine. I can’t leave my front door right now and run a marathon. I haven’t been training for that. I don’t have the endurance.. the stamina. But (if I was super crazy) I could begin training. In other words, conditioning my body to accept greater and greater demands without a proportionate draw on my energy stores. What you consider “blowing it out” on the treadmill is actually something your body has seen before and it’s ready for you. It will shift quickly into the most efficient expenditure of energy.

This is why those calorie counters on your phone, watch or exercise machine are NEVER accurate. They rarely take into account that 15% for normal living. That’s where the real magic is. Research shows that just becoming more mobile through every day activities can up your caloric burn by 500 calories. No jogging required! The reason is the variability of the movement. The body is constantly upended in its quest to get you into an efficient rhythm.

Extending a cardio session will burn calories but there are systemic costs. Repetitive movements (long steady state cardio like cycling) can exacerbate imbalances in muscle function, potentially inviting injury. As midlife women, the drop in hormones leaves us a little more vulnerable, particularly to soft tissue damage. Think knee arthritis. So common in midlife women and maybe unnecessary???

And here’s what really freaks me out. Cardio load past 30 minutes searches for deeper fuel like proteins found in muscle tissue. Like the classic couriers that were all rope and sinew body types. You may lose all important strength pushing unnecessarily.

Muscle mass declines year by year after 30 years old. More so in women than men. Next time you are at the hospital, look around. Count the women who have fallen and broken something. They may be a little older than you now, but when they were your age they maybe pushed on the treadmill too. Thinking they were staying in shape. No one explained that they needed to prioritize muscle and strength.

When you combine the erosion of muscle mass with the hormonal changes women go through, you can see the risk of what the medical community calls sarcopenia. It’s a general weakening of strength leading to frailness and risk of falls. Number one killer of women 65+ who have had accidents.

So pushing yourself to burn more calories on the treadmill isn’t great.

But the biggest cost may be in the time necessary. Cardio workouts with weight loss as the goal require hours. This takes away from all the other joyful activities you may desire. It may leave you quite exhausted afterward.

When I was working, feeling my desk job was causing me to gain weight, I would push and go to the gym after work. I’d spend about 40 minutes on the treadmill (gotta burn 400 calories, right?) And then move on to the stair climber. That was cross training, or so I thought. Then I’d get home thinking I had burned 600 calories. I was exhausted and starving. No personal chef. And two teenagers with the classic “when’s dinner” greeting. What do you think I was thinking? Let’s just order pizza. I can afford it cause I worked out, right??? But I never lost weight. I just got more and more exhausted. And ate less and less healthy. And the 4 slices of pizza I gobbled because I was STARVING were way more than 600 calories. It doesn’t take any time at all to eat 600 calories.

But isn’t it important to get your 10,000 steps in for cardio vascular health?

Getting the “blood pumping” is excellent for overall health, but 20 - 30 minutes of the activity provides full benefit. McMaster University in Hamilton, Ontario has been a leading force in the international research around this for over 20 years.

Cardio vascular benefits can be most efficiently gained through varied activities like HIIT, dancing, varied terrain hiking, sports that require many positional changes. Three or four sessions of 30 minutes per week is enough. Compare the time invested in walking on city streets for 10,000 steps (probably 1.5 hours for most people x 7 days = 10.5 hrs per week) to the recommended guidelines of 2 hours. What could you do with a gift of 8.5 free hours this week? That’s a whole work day off!

So the answer is no. Cardio doesn’t help you lose weight. Moving is super important for all your body’s systems, your brain health, your mood, your socializing, your confidence around movement… Take the Zumba class. Go for a pack walk with your dog. Enjoy that paddle. But don’t push yourself with the thought that you will burn calories and lose weight.

Remember you can learn more about why calories in and calories out doesn’t work for midlife weight loss in episode #2. I’ll put the link in the show notes.

What about yoga? Hell YES! We’ll talk more about this on an upcoming podcast, but yoga is great for strength building in so many ways. If you are reluctant to take up a practice because you have injuries or think it might be unsafe, you’ll want to download my FREE “Essential Guide to Yoga for Women 50+”

. I explain exactly why yoga is essential and give you the safety tips you need to use this amazing movement practice for decades to come.