Jill Brown Fitness

What Leads to a Longer Life? Plenty of Exercise or a Good Diet?

You’ve probably heard this before…. and if you’ve followed me for a while, you’ve heard me say it too…

“You can’t out-exercise a bad diet”


Maybe you could in your 20’s or early 30’s, or if you have many hours to dedicate to training every day.  But trust me, it can’t be done for long.

In other words, it’s not possible to lose weight (and keep it off) solely through exercise if you don’t eat right. 

new study in the British Journal of Sports Medicine even suggests that high amounts of exercise won’t undo the effects of a poor diet when it comes to mortality risk.  Other studies have also shown that a proper diet and high levels of physical activity work synergistically to extend your life.  

So should you prioritize one over the other?

That’s a hard no.  But you can start with one, then level up the other.

Even without weight loss, exercise is one of the only ways shown to substantially improves metabolic health.

What is metabolic health?

The five measurements of metabolic health are:

  • Blood sugar
  • Waist circumference
  • Blood pressure
  • Cholesterol
  • Triglycerides

Being metabolically healthy means not being at risk for metabolic syndrome. Metabolic syndrome is a cluster of conditions that increase your risk of heart disease, type 2 diabetes and stroke.

Fact:  Excess body fat increases your risk of diseases like type 2 diabetes, certain cancers and cardiovascular disease.  Hard stop.

When I do consultations, I always ask about who in your family has these conditions.  Maybe it’s you. These are the strongest reasons to start making changes to your nutrition, your physical activity levels or both.  They’re certainly mine.  My mother died off completely preventable diseases. Looking good in a bikini for that cruise you’re taking is not the most important reason… but if it lights the fire under your butt, then it’s a good enough reason in my book.  

The point is, looking better naked is just a side effect of lower body fat.  

How it prevents the onset of preventable diseases is the jackpot.

And it gets even better. 

When you’ve taken control over whichever needs work (nutrition, exercise or both) and you see the numbers on the scale drop, other things improve too.  You will see lower levels of inflammation, better immune function, and more muscle mass, which can all extend your lifespan.  

There’s a lot of crazy information out there… sadly too much of it is BS.  For example, as we get older, we should stop doing cardio. Or the current trend of, “healthy at any weight (or, size).”

Being overweight for too long increases your risk of metabolic syndrome. I love Lizzo and thing her body positivity is awesome… but when she’s 50, some or all of her metabolic health markers will go south. My prediction is she’ll go the way of Adele sooner than later. I’m taking bets!

As for weight lifting or cardio? We need both. But as we age, we should definitely lean into the weight training more. See my next blog post about this.

Having more muscle mass is a predictor of longevity. So, it’s important to hit those weights, or bands, or do body weight exercises and not just do cardio. By “cardio,” I mean walking, light jogging, elliptical machines and the like, where most people tend stay at a steady and comfortable heart rate. I consider cardio exercise as something you can sustain and maintain for a while. Whereas exercises like weight training requires taking breaks between sets. If you’re doing HIIT workouts, you’re probably getting mix of the two…. at least your do in my classes (which you can join for 50% off right now, just use the code HALFOFF at check out).

The Take Home Message:

Exercise is super important for living a healthier and longer life. But without a good diet you may still be at an unhealthy weight or have too much body fat (particularly around the waist). Being overweight raises your risk of metabolic diseases and even certain cancers, all which can certainly cut some years off your life.

I explain more about how “diets” and “calories” actually work in the next post.