5 Reasons Running May Not Help You Lose Weight:

Your Workout Is Always The Same
Your body is an amazing machine. It’s designed for efficiency, meaning if you do the same thing over and over again, the process becomes easier. This applies to your running workouts too. Not only will they start to feel more effortless (even if you’re still sweating and pumping your legs), but your metabolism literally learns and reacts so that fewer calories are burned with the same exercise output.

This is where traditional “steady state” running falls short on a long-term weight-loss plan. Research conducted at the University of Tampa found that doing steady state cardio — such as running on the treadmill for 45 minutes at a consistent pace that’s not near maximal effort (think sprinting) — helps out with weight loss… but only initially. Subjects lost a few pounds during the first week and then kaput! Nothing more. The reason? Within one week, their metabolism had adjusted and now didn’t need to work as hard to burn off the fat.

One of the biggest problems with running at a steady, moderate-intensity pace, is that the calories you burn are limited to the time you spend sweating. So once your body adapts, the benefit is limited. That’s why weight training is oftentimes viewed as better than “just” running for fat loss. Lifting weights impacts your metabolism by causing mini-micro tears that need to be repaired. That healing process requires energy, which means you’re burning more calories — a process that can sometimes last for nearly two days after your training session.

To put it more simply: With cardio, you can slog away for 30 minutes at a lower intensity and burn 200 calories — or you can just eat 200 fewer calories per day. It’s the same thing. With weight training (or as you’ll soon find out — sprints), that’s not the case. The calories you burn are not limited to what you do in the gym. So while a little variety might not seem like a big change to your routine, it will have a dramatic impact on transforming your body.

You Go Longer, But Not Faster
One of the most important variables with any type of exercise — cardio or other — is intensity. If you look at the average person who runs, they pick a pace that they can maintain for a long duration. Think about it: When you jump on a treadmill, elliptical, or bike, you’re starting with the intent to be on there for a while. Whether it’s 30 minutes or an hour, your goal is to push at a pace you can sustain, work hard, feel tired, and then go home. While this is great for endurance, it’s not so great for fat loss.

A study in the Journal of the American Medical Association followed the exercise habits of more than 34,000 women and concluded that it took about an hour a day of moderate exercise (walking at 3mph) to maintain weight. Notice, that’s not weight loss. And three miles per hour is not very fast.

Now imagine if instead of arbitrarily picking an amount of time to exercise, you focused on pushing yourself to certain level of difficulty. If the 3.0 on a treadmill would be a “four” on a difficulty scale of one to 10, what would happen if you pushed yourself at an eight or nine for a shorter period of time?

There’s no need to guess, I’ll tell you: More fat loss. Researchers at the University of Western Ontario compared short but intense exercise to long, less-intense cardio. One group performed four to six 30-second “sprints” while the other group did cardio for 30 to 60 minutes. The results were nothing short of amazing. Despite exercising for a fraction of the time, those in the sprint category burned more than twice as much body fat.

That’s because the process of sprinting causes similar internal changes to your body as those that occur during weight training. Your body needs to replenish it’s ATP (energy), convert lactic acid that’s produced during exercise into glucose, and restore your blood hormone levels after an intense workout. All of those processes mean your body works harder and burns more fat — both of which don’t happen during steady-state aerobics.

You Focus Too Much On Calories Burned
One of the most common weight-loss mistakes is believing that the majority of the calories you burn results from exercise. This is a dangerous misunderstanding. Simply being alive — sleeping, standing, eating, thinking — requires a tremendous amount of energy. The number of calories you burn at the gym actually pales in comparison to normal functioning and your daily activities that are not exercise based.

Does that mean there’s no need to hit the gym? Of course not. Exercise has many health benefits, but the type of exercise you perform in the gym will influence how many calories you burn outside of it. Running will burn calories, but sprinting or lifting weights will result in more muscle. And the more muscle you have on your body (no — not the “bulky” muscle of bodybuilders), the more calories your body burns just functioning.

You Don’t Try Other Forms Of Cardio
Now that you know muscle is important to your overall weight-loss goals, it only makes sense that you would want to do the type of training that helps this happen in the least amount of time. So if you’re a lover of slower, longer duration cardio, I have some bad news: “Endurance” running and walking (longer duration, lower intensity) impairs strength and muscle growth, according to research in the Journal of Strength and Conditioning Research. What’s more, even if you increase the intensity and run on an incline, cycling is still better for gaining muscle and burning fat, say researchers from Stephen F. Austin State University.

Again, the point here is not that “running doesn’t work” or that there aren’t any benefits. This is about finding the most efficient weight-loss strategy. And if you’re short on time, you might be better served by cycling (preferably at a high intensity) as opposed to going for a longer walk or jog.

You Run Too Much (Yes, Too Much!)
This might sound crazy, but just hang with me: The number on the scale might not be changing because you’re running too much. While this isn’t a problem for the majority of people struggling to drop a few pounds, I’ve worked with more than a few people — and seen hundreds of other case studies — where fat loss has been stunted by doing too much.

Exercise is an indisputable component of a healthy life, but it’s still stress on your body. And the demands of that stress impact your hormones, which also control your ability to lose fat. More specifically, the hormone cortisol is released when you exercise. All cortisol is not bad (despite what late-night TV and supplement ads might have you believe), but chronic stress and chronic cortisol can lead to insulin resistance which forces you to store belly fat against your best-laid plans. Research published in the journal Hormone Research found that long distance running — like that done in endurance runners — causes a sustained increase in cortisol. And this increase in cortisol for long period of times can lead to more inflammation, slower recovery, breaking down your muscle tissue, building up fat, and even harm your immune functioning.