Science and experts alike say high-intensity interval workouts reign as fitness royalty. Touted as a top-notch method for weight loss, improving your VO2 max and even helping you run faster, it’s no wonder this approach to exercise holds such high wellness honors.

Of course, just like any workout you do over and over, the routine can get stale. That is, until you learn the foundation of HIIT workouts and then switch it up every time you go to break a sweat. Allow trainer Adam Rosante, creator of Two Week Transformation and author of Super Smoothie Revolution, to break down the basics so you can turn up the benefits.

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HIIT Workout: What You Need to Make It Work

“The foundation [of HIIT] is a series of intervals of intense activity, coupled with intervals of less-intense activity or complete rest,” says Rosante. “Beyond buzz, it’s popularity can largely be attributed to its efficiency. HIIT’s a great way to get fit in a short amount of time. But the key is to ensure that the high-intensity intervals are truly performed at your highest intensity.”

How do you know if you’re HIIT-ing it hard enough? Rosante says to go at 80 to 95 percent of your maximum heart rate during the work intervals, and 60 to 65 percent during your rest periods. (To find your max heart rate, just subtract your age from 220. Then take the percentages from there.) If you don’t have a heart rate monitor, push hard enough through the work intervals that you’re sucking wind. You shouldn’t be able to hold a convo, Rosante says.

You can do a HIIT workout with almost any exercise, from plank hip dips to jumping jacks to everyone’s favorite: burpees. That’s because it’s more about intensity than the specific movements, Rosante explains. But to help you narrow down what to do, Rosante says he prefers a mix of moves that force the glutes, quads and hamstrings (the body’s biggest muscles) to work explosively. Some of his go-to’s include jump squats, plyo lunges and sprints.

But don’t stop there. Rosante often alternates between a lower body and upper body move, or a lower body and total body exercise. “The alternation forces your heart to pump blood out to the muscles in a much higher volume, which, naturally, means your heart rate is significantly elevated,” Rosante explains. “When you boost your heart rate like this, you disrupt your metabolic pathways in such a way that they’re scrambling to return to normal long after the workout has ended.” This concept of burning calories even after you stop busting a move — known as excess post-exercise oxygen consumption or EPOC — will blast fat and calories, fast.

RELATED: How to Beast Box Jumps and Other Plyometric Exercises

Choose Your Own HIIT Workout Adventure

Spike your heart rate, tone your body and break through plateaus with this HIIT formula from Rosante…

Getting a new pair of shoes has always been a bittersweet occasion for me. Once the joy of finding that perfect pair—and the tiny, happy rush of the purchase—has worn off, I’m left to grapple with the comfort conundrum: those awful initial wears before your new shoes are broken in (or is it your feet that need breaking in?). Whether it’s the highest heels or the lowest flats, I’ve yet to find a pair that doesn’t literally rub me the wrong way, from the common heel blister, to the painful chafing on the tops of my toes, to those more unexpected issues like booties that bite at the ankle.

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That all changed after I hobbled into the office after a full day of running around New York City to different Fashion Week shows—in heels, of course (it’s a hazard of the job). Our kind associate fashion editor, Flavia Nunez, took pity on my poor feet, dug into her bag, and produced a small miracle.

A seasoned marathon runner, Flavia knows a thing or two about blisters (and shoes) and, thankfully, how to prevent and treat them. The product she handed over is from a brand called Compeed, that, unlike other bandage companies, focuses almost exclusively on blisters. At $9 for a pack of six, they’re a little more expensive than a traditional pack of self-adhesive strips, but hear me out—they’re well worth it. According to their website, the products “use hyrdrocolloid technology that fits like a second skin and stays on all day long.” They’re not kidding. The blister cushions certainly do feel like a second skin, are waterproof, adhere smoothly, do not budge, roll, or wrinkle, and will stay on for days, until you pull them off yourself. You’d probably spend the same amount on bandages that wind up needing to be constantly replaced.

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I now keep the conveniently-sized packs in my purse at all times. I'll pop one on at the first sign of chafing or rubbing, but the tiny pads also prevent blisters from happening in the first place—and instantly make the shoe in question wearable. Taking more unorthodox measures, I’ve also used the larger size on the balls of my feet for shoes that don’t have enough padding, put on a double layer to cushion an already-existing blister (immediate relief), and cut the cushions to size to fit an oddly shaped contour or wrap more neatly around a tormented toe.

They can be a little tricky to find in stores, but luckily we have Amazon for that—and yes, they are qualify for Prime.

Evidence keeps mounting that exercise is good for the brain. It can lower a person’s risk for Alzheimer’s disease and may even slow brain aging by about 10 years. Now, new research helps illuminate how, exactly, working out improves brain health.

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In one research review published in the British Journal of Sports Medicine, researchers examined 39 studies that looked at the link between exercise and cognitive abilities among people over age 50. They found that aerobic exercise appears to improve a person’s cognitive function and resistance training can enhance a person’s executive function and memory. Other exercises like tai chi were also linked to improvements in cognition, though there wasn’t as much available evidence. Ultimately, the researchers concluded that 45 minutes to an hour of moderate-to-vigorous exercise was good for the brain.

“There is now a wide body of research showing that the benefits to the body with exercise also exist for the brain,” says study author Joe Northey, a PhD candidate at the University of Canberra Research Institute for Sport and Exercise in Australia. “When older adults undertake aerobic or resistance exercise, we see changes to the structure and function of areas of the brain responsible for complex mental tasks and memory function.”

RELATED: Here's What Playing an Instrument Can Do for Your Brain

But how does exercise have these effects? Another new study presented at the American Physiological Society’s annual meeting in Chicago explored one possible way. In the study, researchers from New Mexico Highlands University found that when people walk, the pressure of making impact with the ground sends waves through the arteries, which increase blood flow to the brain (also called cerebral blood flow). Getting enough blood to the brain is important for healthy brain function, since blood flow brings the brain oxygen and nutrients.

In the small study—which has not yet been published—researchers used ultrasounds to assess arteries and changes in cerebral blood flow in 12 healthy young adults while they were standing, walking and running. The increases in blood flow were greater when the men and women ran, but walking was enough to spur the effect. “[Increased cerebral blood flow] gives the brain more to work with,” says study author Ernest R. Greene, a professor of engineering and biology at New Mexico Highlands University. “It’s another positive aspect of exercise.”

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Scientists are still exploring multiple ways by which fitness improves the brain. But blood flow is a promising path, since it can also help create new brain cells. The protein BDNF (brain-derived neurotrophic factor) also seems to play a role because it helps repair and protect brain cells from degeneration. Exercise can also boost mood by triggering the release of feel-good hormones and chemicals, like endorphins, which can improve brain health…