There is no wealth without health. It's an ancient principle, but it's truer than ever for today's full-time students. Staying healthy in school can be challenging, especially when you're pressed for time.

But with a little knowledge, you can make maintaining your health a little easier. A well-rounded approach to staying healthy in school—one founded in setting fitness routines, developing healthier food habits, and tracking your sleep patterns—can help you keep your body and mind sharp.

Fitness: Maintaining and maximizing your routine.

The most common reason people give for not exercising is that they're too busy for it, Lifehack writes. The U.S. Department of Health and Human Services recommends that adults engage in at least 150 minutes of moderately intense exercise each week. That seems like a lot—but if you break that 150 minutes down to just 30 minutes a day, five days a week, it's much more manageable.

But setting strong habits means more than just breaking your workouts out into half-hour blocks. Here's how you can get the most out of your fitness.

• Look beyond the typical gym setting. The gym isn't the only place to get a workout. You could take a brisk walk (between 2.5 and 4 mph), play doubles tennis, or rake your yard. You could also add more vigorous activities to your routine, such as jogging, running, or fitness classes. (Just talk to your doctor before starting anything strenuous.)
• Establish a routine. The best time to exercise, according to CNet, is "the time you can stick with for days, weeks, and months." Morning and evening exercise have unique benefits and pitfalls, so finding the time that works best for your schedule will help you set a routine—and stick to it.
• Hold yourself accountable. Fitness apps and wearables can help you stay on track and monitor things like your steps and heart rate. Signing up for team sports can add a level of accountability—and a healthy dose of fun—to your fitness regimen, too.

Nutrition: What's on your plate?

As a college student used to a fast-paced environment, you might understandably rely on eating quick meals between the end of your workday and the beginning of your coursework. But before you reach for your next meal or snack, keep the following tips in mind.

• Eat brain foods. Brain foods, such as fish, raw nuts and seeds, fruits and dark vegetables, are linked to better brain power, the Harvard Medical School says. These foods can boost your brain health and give you more sustainable energy throughout the day—which could help you get better grades.
• Eat healthier snacks. The dietary guidelines for adults from the U.S. Department of Health and Human Services recommend sticking to a 2,000-calorie-a-day diet and getting no more than 15% of your calories from less healthy categories like added sugars and saturated fats. If you're looking for a healthy snack, try unbuttered popcorn, dried fruit, rice cakes, or pumpkin seeds.
• Eat right and stay hydrated. Conventional wisdom has generally held that you should consume three meals per day, with breakfast, not dinner, being the biggest one. But many people are exploring new eating patterns like intermittent fasting and finding positive results. Whatever you do, make sure you do it consistently and that it's making you feel good. Always listen to your body! And don't forget to include at least five full glasses of water.

You can use an app to help you to keep track of your food choices, water intake, and calorie count throughout the day.

Sleep: Why it's important.

One of the biggest components of staying healthy in school is getting enough sleep.

"Sleep is just as important as food, water, and oxygen," says Mary Carney, Western Governors University's director of prelicensure nursing for Indiana.

Here are a few tips that can move you toward a better sleeping schedule.

• Get the full recommended hours of sleep. According to the National Sleep Foundation, you should get between seven to nine hours of sleep per night. Six hours is the absolute minimum. And if you can only get six or seven hours during the night, a 15-minute daytime power nap can fill the gap.
• Limit your caffeine intake before bed. That extra caffeine bump can help you power through your day—but it can keep you up at night, too, so consider avoiding anything with caffeine within four hours of bedtime.
• Set a routine. Try to go to sleep at the same time every night. This will get your body and mind into the habit of slowing down at a specific time.
• Put your smartphone away. Answering emails and scrolling through social media on your phone isn't an ideal pre-sleep habit, and the blue light from the screen makes it harder to fall asleep, the Cleveland Clinic says. (But your smartphone could help in other ways—you could use it to set an alarm reminding you to stop drinking coffee at a specific time, for instance.)

Fitness, nutrition, sleep—these are key pieces of the puzzle of staying healthy in school. By establishing the proper routines and sticking to them, you'll be more alert and energized to tackle your schoolwork.