Exercise: Is It Really Less Important Than Dieting for Weight Loss?

Exercise: Is It Really Less Important Than Dieting for Weight Loss?

I've heard for a while that exercise isn't king when it comes to weight loss. Diet is of utmost importance. I mean, the NY Times said it, so it must be true.1 To be fair, they cited many reputable studies in their report that indicate exercise only goes so far in weight management. The amount you can burn in a single workout session can easily be erased by something innocent like a second helping of dinner or a favorite sweet treat. For many people, hunger also increases after training and leads to overconsumption, which erases or even worsens the desired calorie deficit. I understand it. I can see that exercise may not be the key piece in the giant weight loss puzzle.

That being said, I've always had a nagging suspicion that exercise is more important than we think. We already know that it helps with a variety of issues other than weight loss, including mood/depression, cardiovascular health/blood pressure, blood sugar regulation, hormone balance, improved immune function, etc. People who exercise are healthier overall. Period. But I still felt that exercise, at the right duration and intensity, played a key role in weight management.

Then this study popped up online2 and gave us new insight into what might be happening to our metabolism when we exercise.

Researchers at the Karolinska Institute in Sweden found mechanisms in mice through which exercise counteracts fat storage and reduces inflammation. A compound called kynurenic acid, induced by exercise, was the key.

To understand the big picture, walk me back real quick. Prior to this study, the same group originally published in 2014 that kynurenic acid in the brain, produced through exercise, supports improved brain function. Exercise produces a healthy mind, they explained.

Building on that, they conducted this recent study in which they introduced kynurenic acid orally into mice to reach all tissues, not just the brain. While these mice ate a high-fat diet that promoted obesity and elevated blood sugar, they stopped gaining weight and in turn converted more of their white fat into brown fat, which is the type that is more metabolically active. They also had improved blood sugar control despite no dietary changes.

The theory is that the kynurenic acid in the fat cells promoted this conversion from white to brown fat, while the kynurenic acid in the immune cells enhanced the anti-inflammatory properties.

These two factors, increasing metabolically active fat and reducing inflammation, support the body's ability to burn fat as energy and prevent excessive fat storage.

Sounds good! Lace up those shoes! But then the question becomes, what type of exercise should we do to get these benefits?!? What is the magic formula? Run? Easy walking? Pilates? HIIT cardio? CrossFit? Yoga?

Unfortunately, this study does not demonstrate that the kynurenic acid was administered orally and was not induced directly by exercise. A little digging and another paper provided exactly this information: endurance training.3

Ah, I knew it! I suspected that the time and intensity of training was important. Quick and dirty workouts have their place, but nothing replaces a good old workout to get your heart rate up for a longer workout.

This study showed that subjects who underwent sustained heart disease, in these cases an hour or more, produced high levels of kynurenic acid in their muscle tissue within an hour of exercise. Subjects who performed exercises with shorter bursts of energy did not see these benefits.

Here you go. Cardio for the win, right? Well, mostly I suppose. I think the key to success is remembering that cardio is important and plays an important role in weight management. However, don't let anyone convince you that muscle conditioning, muscle building, and even plyometric activities are important for overall strength and health. It is also very important to vary the routine to prevent injuries and strengthen the body overall!

Now, if you're thinking about what type of exercise is safe for you, let me post a quick disclaimer here. I am not an exercise physiologist. I work with food to help people lose weight, but exercise is such a key piece of that puzzle. I've also been an avid athlete since my early 20s, so I talk about it often with my clients. However, if you need specific advice about what is safe and appropriate for you, please consult your doctor, a physical therapist, or even a certified trainer to develop a plan. My job is to teach that movement is important. For tailored guidance, especially if you have an injury or other limitation, consult a professional! *

If you feel okay about starting something on your own, let me put out a quick plug for one of my favorite online training websites, Fitness Blender.com. For approachable, attainable and fun workouts, this site is the best. Run by a husband and wife team from Seattle, they offer FREE online workouts for whatever fitness level and time period you have available. I'll be honest. We don't always have time for sustained cardio, do we? These workouts can easily fit into your day, whether you have 15 minutes or an hour.

However, the truth is that if you are really serious about losing that weight for good, regular exercise needs to be a part of your routine.

So yes, lace up those shoes and get going, because the evidence is clear: exercise, and especially cardio, supports fat loss. Of course, you also have to pay attention to your diet.

* Always consult your doctor before starting a new exercise program. If you want to try something new, always start slowly and always pay attention to correct form. When in doubt, consult a trainer or teacher to learn the basics before increasing the intensity. Basically, start slowly and slowly to avoid injury!

Inspired by Danielle VenHuizen