When you're under pressure and feeling stressed, you might feel irresponsible taking time off from work. And there's plenty of stress to go around, from high inflation and market volatility to global conflicts and talk of a looming recession.

Ironically, experts say that's exactly when it's most important for you to take a mental health day.

People are reaching such high levels of exhaustion that many are quitting their jobs — 47 million in the last year, to be exact. Now more than ever, you should be taking at least one mental health day a month to recharge, says Michele Nealon, a clinical psychologist and president of The Chicago School of Professional Psychology.

But using your mental health days to de-stress goes beyond simply sleeping in and ignoring your work email — and if inflation can come for your gas and grocery prices, it can certainly come for your local spa or yoga studio.

Luckily, you have plenty of inexpensive options — even if you don't know it yet. "You don't have to spend a lot of money to relax," Nealon tells CNBC Make It, adding that mental health days can be more beneficial for your workplace productivity than you may think.

Here are four inflation-proof tips from experts for using your mental health days to actually de-stress and recharge:

1. Move your body

Whether you take a walk around your neighborhood or do a 10-minute high-intensity interval training routine, make sure to move your body at some point during the day.

Physical activity is commonly linked to better mental health. One recent study in academic journal Elsevier found that early-pandemic lockdowns tangibly decreased people's physical activity, leading to higher levels of anxiety and depression.

"Carving out some time, even modestly, to move your body can really be rejuvenating," says Dr. Kimberly A. Yonkers, professor and chair of psychiatry at UMass Chan Medical School, "Just move your body in joyful ways."

Yonkers defines "joyful ways" as whatever feels comfortable and exciting for you. She advises sticking to your own time frame: If 30 minutes is your sweet spot, don't pressure yourself to move around for a full hour.

The important part, Yonkers says, is finding activities that you look forward to doing. Here are some options:

• Try a new exercise
• Practice yoga at home
• Stretch at random moments of the day
• Walk outside for a few minutes
• Go on a hike
• Dance

2. Eat a nutritious meal and hydrate

During busy workweeks, making balanced meals may be your last priority. But not eating healthily could negatively impact your mood, Nealon says. Healthy eating patterns are commonly associated with positive mental health, especially when compared to unhealthy diets, according to a 2020 study published in BMJ, a medical trade journal.

"Spend time reflecting on 'What can I eat today?' and treat yourself to healthy foods," Nealon says, "Whatever a healthy diet is for you on a given day, spend time nourishing your body that day with something healthy for you."

To save money, you can make yourself a healthy meal at home on a budget: Earlier this month, celebrity chef Guy Fieri told CNBC that whole chickens and Brussel sprouts are great options, since they can each be cooked in many different ways. Your mind will also thank you for drinking lots of water, Nealon adds.

"Remember these three staples: sleep, what we eat and then how we move our bodies," Nealon says, "Those are three staples for keeping us in this marathon of life for the long run."

3. Get some rest

Having a good night's rest can do wonders for your brain, says Dr. Kristin Francis, an assistant professor of psychiatry at the University of Utah's Huntsman Mental Health Institute.

If you've been having trouble getting enough sleep during the workweek, you should absolutely sleep in, Nealon says. Otherwise, Francis recommends going to sleep early at the end of your mental health day, so you can wake up early the next morning and start your day — especially if it's a workday — with an episode of your favorite TV show, or some other method of self-care.

People with full-time jobs often don't get a full night's rest. In fact, 32.6% of working adults surveyed by the Centers for Disease Control and Prevention claimed they slept six or fewer hours a night from 2017 to 2018.

"Most people underestimate the importance of sleep and how important it is for us to be alert and efficient at work," Francis says, "I really recommend taking that day if you need to get caught up on sleep. Your body can get caught up with some extra hours."

Mindfulness apps may help you get better sleep, says Francis, and many of them are free. "The whole goal is to refuel your mental state and energy," she adds.

4. Be productive with your hobby and find balance

Doing nothing might sound like a dream, in theory — but it's actually a bad idea for using your mental health days effectively.

Francis says stress and productivity exist on a bell curve: Too much stress reduces productivity, while too little stress makes you complacent. She says you can find balance by working on hobbies while you're away from your office.

On mental health days, Francis recommends a one to four ratio of getting things done and doing pleasurable activities. Getting one thing off of your to-do list will give you satisfaction and help you feel productive, but spending the remainder of your day doing what you enjoy will help you to unwind, she says. 

"You'll feel a sense of accomplishment for getting that thing off of your list, but then the majority of your day will be spent doing fun and refueling activities," Francis says.

Sign up now: Get smarter about your money and career with our weekly newsletter

Don't miss:

• Do these 4 things every day to be happier and more resilient, according to mental health experts
• Avoid this crucial mistake when taking a mental health break, says a top psychologist