Published December 13, 2025 03:02AM<\/p>\n
To me, there\u2019s nothing better than embarking on a long hike with my dog Ollie. But I work full-time and live in a city, which means that climbing a mountain every day isn\u2019t possible. If I want to get my exercise fix during the work week, I need to jump on my Peloton or head to the gym.<\/p>\n
I genuinely love running on the treadmill, but for most of my life, I\u2019ve stuck to the same routine: a three- to five-mile jog at roughly 9 miles per hour (mph). But a recent trend caught my eye: the 12-3-30 walking workout, which involves setting your treadmill to a 12 percent incline and walking at 3 mph for 30 minutes.<\/p>\n
The 12-3-30 workout was created by health and beauty influencer Lauren Giraldo<\/a>, who claims<\/a> it helped her reach her goal of losing 30 pounds. (Watch her fitness journey in the video below.)<\/p>\n I was curious whether this workout would be as effective as my treadmill runs and, if so, how often I\u2019d need to do it to build strength and maintain my cardiovascular fitness. Here\u2019s what I learned.<\/p>\n Just How Effective Is the 12-3-30 Walking Workout?<\/p>\n Dr. Constance Chu<\/a>, a sports medicine physician at Stanford Medicine, told me the 12-3-30 workout is a great idea, especially for people who don\u2019t enjoy running or can\u2019t run due to an injury. Why? Weight-bearing exercises, or activities where you work against gravity, are known to improve physical and mental health, she says.<\/p>\n Even better: the 12-3-30 workout is low-impact, so you aren\u2019t going to pound your joints as you would while running on a hard surface, making it an effective workout for beginners and seasoned athletes alike, says Joe Hribick<\/a>, a physical therapist and clinical assistant professor of physical therapy at Lebanon Valley College.<\/p>\n When you walk uphill<\/a>, your body experiences a broader range of motion, increased joint movement, and greater lower-limb muscle activity<\/a>. Your lower extremities\u2014specifically, your quadriceps, hamstrings, and triceps surae muscles (a group of muscles located in your calf)\u2014light up<\/a>, which is why incline treadmill walking can be an effective<\/a> way to strengthen your lower limb muscles.\u00a0\u201cThe steeper the incline, the more that these muscles have to work to propel you forward,\u201d says Hribick, adding that these muscles are often undertrained and could benefit from the special attention.<\/p>\n To fully reap the benefits, proper posture<\/a> is key. By leaning forward, your abdominal muscles will work harder to keep you stable, according to Hribick. \u201cWith good form, this increases core activation and helps improve postural control,\u201d he says. Then, swinging your arms will propel you into forward motion.<\/p>\n How Often Should You Do the 12-3-30 Workout for Maximum Benefits?<\/p>\n As is the case with all things, there isn\u2019t a one-size-fits-all solution. In general, most people should aim for roughly 150 minutes<\/a> of moderate-intensity exercise\u2014meaning you\u2019re breathing harder, your heart\u2019s beating faster than usual, and you\u2019re sweating\u2014a week, and the 12-3-30 workout can certainly contribute to that effort, says Hribrick.<\/p>\n To boost leg endurance, muscular strength, and cardiovascular capacity, Hribick recommends that beginners start with one or two sessions a week, and intermediate exercisers can go with three to four sessions a week. If you\u2019re new to the gym, start at a pace and incline at which you can carry out a conversation without becoming breathless, advises Chu. As your cardiovascular fitness improves, you can gradually increase the speed, duration, and incline on the treadmill until you reach the 12-3-30 ratio, she adds.<\/p>\n Finally, don\u2019t forget to carve out time to rest. Recovery days are crucial because posterior chain muscles\u2014your glutes, hamstrings, and calves\u2014can fatigue quickly at higher inclines, says Hribick.<\/p>\n Can the 12-3-30 Workout Replace More Traditional Cardio?<\/p>\n The truth: it depends. Chu explains, the 12-3-30 workout will definitely boost their heart rate enough to count as cardio. \u201cBut for more fit people, it won\u2019t.\u201d Even if it gets your heart pumping, it\u2019s worth doing other types of cardio\u2014like cycling, swimming, the elliptical, or brisk outdoor walking\u2014as well to avoid overuse injuries and achieve well-rounded fitness, says Hribick.<\/p>\n In a recent study<\/a>, 16 participants completed both the 12-3-30 workout and a self-paced run. To accurately compare the two workouts, the duration of the 12-3-30 workout was adjusted to match the energy expenditure<\/a>\u2014the amount of energy it takes your body to move\u2014of the self-paced run. This meant that participants had to extend\u00a0their 12-3-30 workout past the 30 minutes to match the number of calories burned from their self-paced run.<\/p>\n This means that\u00a0to burn the same amount of calories, you would need to do the 12-3-30 workout longer than a self-paced run, which isn\u2019t the best option if you want to burn a lot of calories and don\u2019t want to be in the gym for longer than 30 minutes. Keep in mind that burning calories isn\u2019t the end-all be-all of workout, sometimes it just feels good to get body moving.<\/p>\n If you have a knee injury, ankle pain, low back issues, or struggle with sustained uphill walking, walking on a flat surface or a lower incline may be a better plan, says Hribick.<\/p>\n Those with knee issues who can tackle inclines can make a few adjustments. Here\u2019s what Hribick suggests:<\/p>\n Lower the incline to below 3 percent Also, if your hips or ankles are tight, make a point of regularly stretching your calves and hip flexors before and after working out. The reason: having a limited range of motion in these areas can put even more stress on your knees and lower back, which can lead to an injury, warns Hribick.<\/p>\n Overall, Hribick likens the 12-3-30 to a half-hour hike. \u201cYou get a strong training effect without the repetitive impact forces that occur with running,\u201d he says. To me, the 12-3-30 is a win-win: I still get to squeeze in some hiking even if I can\u2019t get to an actual mountain.<\/p>\n Want more\u00a0Outside\u00a0health stories?\u00a0Sign up for the Bodywork newsletter<\/a>. Ready to push yourself? Enter MapMyRun\u2019s\u00a0You vs. the Year 2025<\/a> running challenge.<\/p>\n
\nDecrease the speed to less than 3 mph
\nShorten your stride length so you\u2019re taking more steps
\nBreak up the workout into intervals (do 3 to 5 minutes at an incline, for example, then 3 to 5 minutes of flat recovery)<\/p>\n