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According to author Robert Pozen, regular exercise increases productivity. Although you might put an emphasis on going to the gym for that reason, are you putting enough energy into arguably the most important muscle affecting your productivity — your willpower?

Studies show that our willpower is similar to other muscles. If little time is spent working on your self-control, you won’t see any improvements. However, unlike your other muscles, you only have a limited surplus of self-control: As our day progresses, our willpower depletes.

If you’re struggling with diminishing willpower, below are nine ways to improve your self-control and max out your productivity.

9 Willpower Workouts to Maximize Your Productivity

1) Eat a hearty meal.

Low glucose levels are directly correlated with to weaker willpower. In fact, a study revealed that participants who were not fed prior to starting a project gave up completing it much quicker than their fully-fed counterparts.

“To keep [your willpower] high, eat regular meals that are full of protein and good carbohydrates, like a sandwich of lean meat and cheese packed between two slices of whole-wheat bread,” Stephanie Booth writes in Real Simple. “And never start a challenging task on an empty stomach.”

Starting each morning with a hearty meal kickstarts your willpower. During the day, snack on almonds, cashews, and yogurt to maintain high energy levels. If you’re unsure of what to eat, HubSpot’s Lindsay Kolowich put together an infographic detailing the ideal diet for maximum productivity.

2) Find the right balance.

Your willpower is a limited resource, meaning you run out of it during the day. Therefore, it’s important to not use all of your willpower too early.

“Because on any given day we have a finite amount of willpower, it’s important that we don’t deplete the well too soon,” Laura Entis writes in Entrepreneur. “Instead of simply writing down obligations on your calendar, rank them in terms of the energy or self-control they will require.”

If you’re struggling to determine which of your tasks requires the most attention, prioritize your to-do list with an impact versus effort analysis.

Here’s how it works: Write down your tasks and rank each one based on how much impact it will have on your productivity and how much effort it will require. Once you finish ranking your tasks, begin working on your low effort, high impact goals to build up steam, then transition to your high effort, high impact goals.

3) Commit to an outcome before starting.

Instead of allowing yourself to duck out of your commitment, make a “down payment” to ensure you’re going to follow through. In other words, give yourself a reason to complete a task before starting it.

“Make it inconvenient to give into your temptation,” Emily Co writes in PopSugar. “It won’t stop you, but it will make it harder to go against your goals. For example, schedule a session with a personal trainer, or bring a set amount of cash with you when you’re on a budget, and leave your credit cards at home.”

For example, a colleague of mine felt she was commuting to work with Uber too frequently. To counteract that, she purchased a monthly subway pass. By spending the $75 dollars for the pass, she’s committing to riding the MBTA. Otherwise, it’s just a waste of money.

4) Meditate every morning.

Although it looks simple, sitting still with perfect posture and balancing your thoughts is difficult.

But the benefits of meditating go beyond 15 minutes of quiet every morning. In fact, quite a few successful executives, including HubSpot’s Chief Technology Officer Dharmesh Shah. say meditating keeps them calm.

According to Headspace, an eight-week 2012 U.S. study found that employees who meditated experienced improved willpower and focus. After conducting three studies, the researchers discovered that “those trained in meditation stayed on tasks longer and made fewer task switches, as well as reporting less negative feedback after task performance.”

Instead of reaching for your cell phone first thing in the morning and checking email, try spending 10 minutes meditating and reap the willpower benefits. 

5) Exercise regularly.

According to author and willpower expert Kelly McGonigal, regular exercise — whether it’s light yoga or an intense physical workout — is linked to improved willpower.

In fact, a Netherlands study revealed that a quick workout correlated with better self control, among other significant benefits.

“The researchers suspect that exercise may improve self-control by increasing the flow of blood and oxygen to the part of the brain—the prefrontal cortex—that controls higher brain functions,” Shawn Radcliffe explains.

Going to the gym not only strengthens your willpower, but also improves your overall health. If you’re struggling to find time for the gym, try out these 10 tips for exercising without leaving your desk.

6) Get a good night’s rest.

A good night’s rest supplies you with both the mental and physical energy to make it through the following day. If you miss out on sleep, you’ll feel tired and your willpower is likely to drop to an all-time low. In fact, a lack of sleep can result in lower reaction speed and an inability to think clearly. One study found that this fatigue-impaired state is equivalent to being drunk.

“Adequate rest improves our self-control and provides an optimal environment for the brain to function,” Ryan Clements writes. “Rest reduces the body’s need for glucose, and it allows the body to make better use of what we have.”

A good night’s rest normally means getting seven to eight hours of shut-eye for an adult. If you’re struggling to fall asleep, studies suggest getting away from screens and reading a paperback book. The light from device screens messes with our circadian rhythm, making our bodies believe it’s daytime when it’s really time for bed.

7) Practice what you’re trying to do.

Yep, we talkin’ about practice. If you want to run a marathon, you can’t just jog a few times to get in shape — you have to train your body for distance running. Your willpower works the same way.

“Just like lifting a barbell strengthens your arms, pushing through a problem will bolster your willpower,” Nathaniel Eliason of Zapier writes. “The cool thing is that this doesn’t have to be huge, arduous tasks: Any amount of stress on your willpower will strengthen it.”

If you’re struggling with a certain technique or skill, make sure you set aside time to practice it. Try Jerry Seinfeld’s “don’t break the chain” technique: Mark a red X on your calendar every day you practice a task, then focus on not breaking the chain of red X’s. This mentality ensures you’ll practice every day.

8) Smile often.

Studies show smiling — even faking one — improves your mood.

And this is important for willpower: The happier you are, the more likely you can resist temptation and complete your goals. Researchers had volunteers resist temptation to deplete their willpower.

Afterwards, “participants who watched a comedy video or received a surprise gift self-regulated on various tasks as well as non-depleted participants and significantly better than participants who experienced a sad mood induction, a neutral mood stimulus, or a brief rest period,” the researchers write.

In the event you become overwhelmed with stress or feel a little blue, remember to smile. It’ll boost your mood, your willpower, and likely put you on a path towards productivity.

9) Hold yourself accountable.

If you’re struggling to build up your willpower, being hard on yourself when things go wrong can be effective. For example, if author Chrisoula Andreou doesn’t exercise five times a week, she can’t eat out on Friday night.

For some people, punishing themselves for lack of willpower isn’t the best way to build up strength, but for others it can be incredibly effective. If you’re struggling to find self-control, establish a set of rules and hold yourself accountable when you break them. For example, if you commit to spending three hours prospecting each day, but only follow through on one hour, don’t let yourself indulge in your favorite leisure activity that night. Instead, spend the time searching for potential fits.

Getting through the day can be draining. For some, a lack of willpower and an overwhelming to-do list can join forces to kill productivity. While willpower is a unique “muscle,” you still can work it out and build up strength. Use these nine tips to build your willpower when you’re productivity is plateauing.