10 Ways Your Workouts Could Actually Be Causing Weight Gain

Diet and exercise are often the main focus when the goal is weight loss. But weight loss has a lot of gray areas and does not boil down to just two components.

Besides genetics, there are several lifestyle factors that come into play in addition to diet and exercise. For example, excessive stress and lack of quality sleep can both make losing weight more difficult, as can certain stages of life, like menopause.

There is evidence that suggests that poor gut health plays a role in making weight loss more difficult.

And the typical advice to just eat less and move more to lose weight has not been proven successful.

Unfortunately, many people are still stuck on the diet and exercise hamster wheel for weight loss and end up seeing no results—or seeing their weight increase. And while exercise—including both cardio and strength training—is effective for decreasing body fat and increasing muscle, it might not show up on the scale in the way you want.

Here are 10 ways your workouts might be causing weight gain.

You May Be Consuming Extra Calories

Engaging in regular exercise may increase your appetite—especially if your body is burning more calories than it's used to. However, this is not a hard and fast rule. A 2023 review in Appetite reveals that it can go either way. Some studies show an increase in appetite and others don't—it really is an individual response.

If you find your appetite has increased since you started exercising, it may just simply be your body's way of telling you it needs more fuel. You want to make sure you're eating enough calories, including protein, so that the weight you're losing is more fat than muscle—and so you don't reduce your metabolism.

With that said, sometimes we use exercise as an excuse to eat more than we need. Instead, pay attention to your hunger and fullness cues. Eat enough to satisfy your hunger and stop eating when you start to feel full. This also requires eating slowly and mindfully so that you can pick up on your body's cues.

Some people find it helpful to track their food and exercise to get an idea of how their caloric intake compares to their calories burned. You can use a free app, like MyFitnessPal, for this purpose. Just keep in mind that it is not an exact science and many things influence weight beyond just calories used and eaten. So it's important to also incorporate more mindfulness and honoring what your body needs in addition to tracking if you decide to go that route.

You May Be Refueling With Unhealthy Snacks

There are dozens of nutrition bars, snacks and beverages geared toward athletes and gym-goers looking to refuel after a workout. Most of our staff has a favorite nutrition bar for on-the-go snacking.

These products are convenient, but many have more calories and sugar than your body may need after a long walk or elliptical session.

Drinking a 20-ounce bottle of original Gatorade will add 140 calories and 34g added sugars to your daily diet, while a chocolate chip Clif bar adds around 250 calories and 16 grams of added sugars.

Many of these products were designed for longer, more strenuous workouts that include plenty of sweating—so if that's your jam, they may be appropriate. Otherwise, you're probably better off opting for a container of plain Greek yogurt with berries, hummus with carrots and pita bread or another healthy snack that isn't so high in calories and added sugars.

You Might Not Be Properly Hydrating

While it is commonly said that our bodies confuse hydration and hunger, research does not show a clear association. And according to MedlinePlus, hunger is not a sign of dehydration. What is most likely happening when you feel hungry and drink a big glass of water is that you're filling your stomach up with water. This can temporarily take away the feeling of hunger in your belly.

With that said, if you've been on the slightly dehydrated side and you start to hydrate more with exercise, your body may initially hold onto more fluid. As you continue to hydrate, your body will eventually get rid of the extra fluid it doesn't need (and you'll be running to the bathroom more often).

There are also benefits to your weight with hydration. According to a 2021 study in Clinical Nutrition, being well-hydrated is connected with weight loss and reduced waist circumference.

While water is typically enough to hydrate during exercise, if you're engaging in higher-intensity workouts, especially in the heat, plain water might not be enough. Rehydrating your body after an intense sweat session should also include replenishing electrolytes like sodium and potassium. So if you're sweating a lot during your workout, you may want to snack on a banana or sip on coconut water afterward to get a healthy electrolyte boost—without the added sugars sports drinks offer.

You Use Your Workout As an Excuse to Be Sedentary the Rest of the Day

Sometimes we can get into the mindset that if we exercise, we don't have to do anything else for the rest of the day—and sometimes we need that. But according to a 2023 study in the Journal of Functional Morphology and Kinesiology, non-exercise physical activity (NEPA) is a simple way to burn up to 350 extra calories a day without stepping foot inside a gym. Things like taking the stairs, gardening, walking your dog and cooking—even using a stand-up desk—are all examples of sneaking in more physical activity that can boost your overall calorie burn,

If you're sore from yesterday's workout, it might be tempting to move less today. But engaging in more gentle movement—like going for a walk—helps increase blood flow to the muscles and can help relieve muscle soreness and fatigue.

You Only Do Cardio

While trying to lose weight, many people jump onto the cardio bandwagon. And cardio is important for strengthening your heart and lungs—and if you enjoy it, all the better. But many avoid strength training (which has also been shown to have heart and lung health benefits) and are missing out on a host of benefits that hitting the weights can offer.

For example, a 2022 review in Obesity Reviews suggests that resistance training increases strength and lean body mass—which includes muscles and bones. While it's more complicated than this, in simple terms, having more muscle on your frame will burn more overall calories and change your fat-to-lean tissue ratio in a positive direction.

But here's the thing: This change doesn't show up on the scale as quickly as it might when combining eating fewer calories with just cardio exercise. When you lose weight quickly, you also lose a lot of muscle mass. And while this will show up on the scale as losing weight, your fat-to-lean tissue ratio will be worse—and this ultimately is not what you want for long-term weight maintenance and health.

Another reason to add strength training to your toolbox? Maintaining and adding muscle mass to your frame can help your metabolism. This is crucial, since weight loss and eating fewer calories can actually slow your metabolism down.

You're Too Obsessed With the Scale

The scale doesn't tell the whole story regarding your body—like what percentage of your weight is made up of muscle, bones and organs versus how much is fat. Your weight can also fluctuate several pounds throughout the day from things like fluid intake, how much you've eaten (even healthy meals weigh something) and whether or not you've had a healthy poop.

Many people weigh themselves immediately following a workout, thinking the calories they just burned will show up on the scale. Unfortunately, this is not how the body works—and you might even see the number higher than before you worked out. This is because exercise—especially higher-intensity exercise—can produce a temporary inflammatory response in your body. This can also trigger temporary water retention.

Rather than depending on the scale to gauge your progress, focus on the way you feel, your energy level, the way your clothes fit, how well you're sleeping, your mood—anything other than the scale.

You're Not Getting Enough Quality Sleep

When it comes to weight loss, most people focus on diet and exercise. But there is another component we often leave out of the equation—sleep.

Getting the recommended seven to nine hours of sleep each night is essential for losing and maintaining weight because it affects certain hormones in our bodies that regulate hunger and fullness. Being well-rested gives us the energy to power through a workout and can help us make healthier food choices.

Research, like the 2023 review in Cureus, suggests that the relationship between sleep and exercise is bi-directional—meaning sleep affects how well your workouts go, and exercising can influence how well you sleep.

As far as the ideal time to exercise to help you sleep better, the research is inconclusive, according to a 2019 study in Sports Medicine, so choose a time that works best for you. If you've been working out in the evening and you're not sleeping well, consider putting more time between your workout and bedtime, as higher-intensity exercise close to bedtime has been shown to interfere with sleep.

Sometimes the lack of quality sleep is caused by a sleep disorder, such as insomnia or sleep apnea. Besides affecting weight, sleep disorders can have other negative health consequences. For example, insomnia has been linked with a 69% greater risk of heart disease—as can sleep apnea. If you suspect either of these conditions, work with your healthcare practitioner to find solutions.

You're Not Challenging Yourself Enough

There's a difference between working out for health improvements and disease prevention and working out for weight loss. It doesn't take nearly as much exercise to prevent disease and see improvements in your health compared to what it takes to improve your fitness level and see changes in your body composition and weight.

For example, there is evidence that suggests that as little as 5 minutes of exercise per day may improve heart health. And that 4 minutes of walking a day may reduce your risk of cancer. But that small amount of exercise will not be enough to healthfully lower your weight.

And if you've been working out faithfully and are no longer seeing results, it's time to switch things up. Our bodies have an amazing ability to adapt. And if you've been doing the same tired routine every time you work out, eventually your body becomes more efficient at it. And while it will maintain the status quo, you most likely won't see improvement—unless you change your routine, change the type of exercise you're doing or change the intensity of it.

You Have an Undiagnosed Health Issue

If you feel like you've got all the bases covered—you're eating a healthy diet, exercising, managing your stress and getting plenty of quality sleep—it could be possible your weight loss efforts are being thwarted due to a health condition (or maybe your body has reached its "settling point" and it's telling you it's happy where it's at).

Hormone-related conditions can lead to unwanted weight gain, even if you're engaging in healthy habits. For example, polycystic ovary syndrome (PCOS) affects about 5 million women of reproductive age per year. PCOS can cause insulin resistance, chronic inflammation and weight gain.

Issues with your thyroid can also cause weight issues—both unexplained weight loss and weight gain.

Schedule an appointment with your healthcare practitioner if you suspect something is off in your body for testing.

You're New to Exercise

If you've just started working out regularly—either for the first time or have just been out of your routine for a while—you may be experiencing what we discussed earlier regarding inflammation and fluid retention.

It's important to ease your way into a fitness routine, so your body can gradually adjust to all the changes going on. Starting with workouts that are too intense or too frequent and don't allow your body recovery time will increase the likelihood of temporary inflammation and fluid retention.

It's OK to start your fitness journey with walks around the neighborhood and simple bodyweight exercises—like modified push-ups, squats and plank. Increasing your NEPA can also help your body acclimate to increased movement in general.

The Bottom Line

Regularly exercising and being more active overall is integral for a healthy body and mind—even if you don't lose weight because of it. Be careful about allowing some of the potential temporary side-effects of exercise to be an excuse to avoid it. Keep the long-term big picture in mind, and step off the scale and use other factors to gauge your progress. Now lace up your shoes and get moving!