Amy Schlinger is a National Academy of Sports Medicine Certified Personal Trainer (NASM-CPT) and freelance journalist with over 12 years of experience. She regularly covers health, fitness, wellness, and lifestyle topics for Shape, Health Magazine, Self, Women's Health, Men's Health, The New York Post, Business Insider, Livestrong, Well + Good, MSN, and more. Her work has also appeared in Glamour, Cosmopolitan, Outside Magazine, Runner's World, Pilates Style, and more. She has held staff positions at Shape Magazine, DailyBurn, Self Magazine, Hearst, and PopSugar. She earned a BA in Media Arts and Design from James Madison University and is currently based in New York City. Amy has run six half marathons, completed two triathlons, biked two century rides, finished two Tough Mudder races, and four Spartan races.

There's no denying that 2022 is the summer of the "hot girl walk," at least according to TikTok, where the low-impact exercise has become a viral sensation thanks to nearly 400 million views on videos with the #hotgirlwalk hashtag. Plus, walking is also a beneficial, low-impact way to get in some cardio. "Walking is a great form of low-intensity steady state [LISS] cardio, or cardio training at a low intensity that you do anywhere from 45 minutes to an hour," says Noam Tamir, C.S.C.S., strength coach and founder of TS Fitness in New York, NY.

Walking is an important daily physical activity with research backing its many benefits, suchas improving cardiovascular fitness, increasing energy levels, and even improving mood and boosting immune function. Of course, taking a walk just for fun or to get your vitamin D-fix is reason enough to get outdoors, so not every stroll needs to turn into a heart-pumping workout. But for those days when you're craving a bit of a challenge, increasing the difficultyof your walk can do just that. Here, top trainers share tips on how to level up your daily steps and add intensity to your jaunts.

Your walking workout might be on the treadmill or outside, with you moving at a comfortable pace, but is it feeling a bit too easy? "You should be moving at a challenging steady pace, one where you can keep it moving, but you're also not too comfortable," says Mathew Forzaglia, an NFPT-certified personal trainer and the owner of Forzag Fitness in New York, NY. "You want to be at about 65 to 75 percent of your max heart rate, which, if you have access to a heart rate monitor or a watch with built-in heart rate reading, you can use to help you track."

Don't have a heart rate monitor? Use the "talk test" as a way to measure intensity. You want to be moving at a pace where you can speak but can't sing; you can talk in full sentences, but you're slightly out of breath.

By adding some extra weight to your walk, you're adding resistance. "Weights can mimic the resistance of the levels on an elliptical," explains Tamir. "By adding resistance, you're increasing your heart rate and improving overall cardiovascular health." While you can use handheld weights, wrist weights, or ankle weights, Tamir suggests a weighted vest. "It distributes the weight more evenly, where something like ankle weights can change your overall gait, which you don't want to do," since an altered gait can strain your ankle joint and increase your risk of injury.

There's no doubt that walking has benefits including improved endurance, less stress placed on the body, and increased cardiac efficiency. However, adding some speed intervals into your walk brings different benefits to the otherwise chill cardio workout. "By incorporating some faster intervals, you'll work on heart rate variability, improve your cardiovascular health, and also burn more calories," explains Tamir. "Not only will you burn more calories in less time, but you'll also increase the excess post-exercise oxygen consumption, or EPOC, which allows the body to keep burning calories even after you're done exercising." Or put another way, the workout may be over, but your metabolism remains elevated for a period of time afterward.

If you live at or near elevation (defined by a study in Respiratory Research as 5,000 feet or higher), try taking your walk to new heights. "Exercising at [a higher] altitude can increase the flow of oxygen to your muscles so that they fatigue slower," explains Tamir. That's because as a 2016 study found, altitude training can increase erythropoietin (EPO) production, and EPO is a hormone that makes red blood cells, which deliver oxygen throughout your body.

Altitude training also improves your VO2max, or the amount of oxygen your body consumes during exercise, which improves endurance, explains Tamir. Research backs up these claims: A study in the Journal of Exercise Nutrition and Biochemistry showed that exercising at altitude was more effective than sea-level training in delivering oxygen to athletes' blood and muscles. Another study in the European Journal of Applied Physiology found that training at altitude improved VO2max in elite distance runners.

TL;DR: If there's a hike you've been meaning to try or you live near some hilly trails, consider changing up the setting for your usual walk. That way, you can enjoy the benefits of elevation and exercise in nature at the same time.

For advanced walkers, changing the way you breathe during your miles can also increase the intensity. "Keep your mouth closed and breathe [in and out] through your nose while you find a steady pace that's hard, but [a pace] that you can keep," says Forzaglia. "Not only are you challenging your nervous system [by concentrating on a new breathing method], but you're also lowering your respiratory rate or the number of breaths you're taking during exercise." Translation: You're putting in more work to consume the same amount of oxygen that you would by breathingin and out through your mouth. As a study in the International Journal of Kinesiology and Sports Science shows, this type of nasally restricted breathing pattern doesn't result in a lower level of cardio fitness. Nasal breathing is challenging at first and may feel uncomfortable, but over time, studies show that it gets easier and your breathing will become lighter and more efficient.

If you live near the water, consider a sandy beach walk vs. a stroll on the solid pavement. "I suggest doing this barefoot," says Tamir. "The sand provides an unstable resistance, forcing your body and especially your feet to work harder. You'll not only get cardiovascular benefits from the walk itself, but you'll strengthen your feet, too." That's because when you're walking in sand, "your nervous system has to recruit additional muscle fibers in your legs, hips, and trunk in response," as Rocco Bergin, a trainer for the Sports Center at Chelsea Piers in New York City who often leads workouts in the club's sandpit, previously told Shape.

Not lucky enough to leave near the beach? Try mimicking the resistance of sand walking with pool walking; the water adds resistance to your walking without impacting your joints, as Shape previously reported. You can also experiment with walking on a variety of surfaces, such as grass or dirt trails, to help strengthen your feet

Walking may be a cardio workout, but you can still incorporate strength exercises into your conditioning. "Along your route, stop to do some bodyweight exercises like squats, lunges, skaters, or even bench hops," says Tamir. "You'll work other areas of the body, while still keeping your heart rate raised."

Having a variety of options to add intensity to your walking workout can make your usual walking routine feel fresh. Try adding these progressions to your next few walking workouts and see which variations help you stay motivated to move.