Does Running Give You Abs? What Actually Works

Does running give you abs? Running works your abs but rarely reveals them on its own. Your abdominal and lower-back muscles switch on with every stride to hold your trunk steady. They work harder as you pick up speed. Whether a six-pack shows depends mostly on how much fat covers those muscles. That comes down to diet, overall training and genetics.

So if you're asking "does running work your abs," the answer is yes, mostly by holding your trunk steady. Running won't build the muscle you see the way direct core work does, and it won't burn belly fat in a targeted way.

The plan below adds three things to a normal running week: one short speed session, two strength sessions and a 10- to 15-minute core routine two or three times a week. The diet section covers the calorie and protein numbers, which largely decide whether any of it shows.

Quick Answer: Does Running Work Your Abs?

Yes. Running works your abs, mostly as stabilizers. In lab recordings, your core muscles switch on around each foot strike, and abdominal activity rises as you run faster (Saunders et al., 2005). That builds endurance in your core. Seeing your abs is a separate question, and body fat is the main factor.

Research hasn't pinned down a body fat percentage at which abs appear. For reference, the American Council on Exercise (ACE) lists 6 to 13 percent body fat for male athletes and 14 to 20 percent for female athletes (ACE body-fat categories). Those are athlete categories, not a six-pack threshold.

Where your body stores fat is partly inherited (Shungin et al., 2015), so two runners at the same body fat can look quite different around the middle. Running still helps by burning calories and, at faster speeds, by asking more of your core. It works best alongside the strength, core and diet changes below.

Why Faster Running Works Your Abs Harder

Your core doesn't do the same job at every pace. In one lab study, researchers recorded the trunk muscles of seven people walking and running on a treadmill at speeds up to 5 meters per second, about a 5:22-per-mile pace. Activity in the abdominal muscles and the lower back increased with speed, and the deep transverse abdominis stayed active the whole time (Saunders et al., 2005).

That doesn't turn each stride into a crunch. When triathletes and active nonrunners ran on a treadmill for 30 minutes at moderate and fairly hard efforts, their external obliques worked less than during a set of curl-ups, while their lower-back muscles worked more than in a back-extension exercise (Behm et al., 2009). Running is good endurance work for core stability, but it doesn't replace direct work on the muscle you see.

Speedwork may also help a little with fat loss. In a 2019 meta-analysis, interval training and steady moderate exercise lowered body fat percentage by about the same amount, roughly 1.5 percentage points, though interval training cut about 28.5 percent more total fat mass (Viana et al., 2019). That's a small edge, not a reason to drop your easy runs.

Which Kind of Runner Are You?

Your current training changes what to add first. Your starting point is in the table below.

For your running, neither type beats the other. If you're chasing visible abs, it just changes where your time is best spent.

A Weekly Plan for Stronger, More Visible Abs

No need to do it all every day. Here's how speedwork, strength training and core work fit around a normal running week.

• One short speed session a week, ideally after an easy day rather than another hard one. If fast running is new, start with strides. Add 4 to 6 relaxed accelerations of about 20 seconds each after an easy run. Build to a quick but controlled pace before walking back to recover. After a few weeks of comfortable strides, swap in hill sprints. Keep them short, 6 to 8 seconds, and hard but not all-out, with a full walk back down between reps. Warm up before any of it. Stop if anything hurts or a hamstring starts to tighten.
• Two short strength sessions a week built around compound lifts, not sit-ups alone. Think squats, deadlifts, presses and rows. Your trunk braces under the weight to hold you steady. Everything else gets stronger too. New to lifting? Nail the form with light weights before adding more. Runner's legs covers the same compound-lift approach for your lower body. Combine both into one strength routine if you want.
• A short core routine 2 to 3 times a week (see below), after an easy run or on an easy day.

If you're a steady-state runner, add all three (see the table above). Your speed session is covered if you already do regular intervals or hill work. Keep the strength and core work, and skip the extra speed day.

A Simple Core Routine for Runners

Expect two or three rounds to take about 10 to 15 minutes. You need just a mat and one dumbbell or kettlebell. Four of the moves train what your core does on a run. They keep your torso steady while your arms and legs move or a weight pulls you to one side. The fifth, the reverse crunch, works the muscle you see.

Begin with one round twice a week. Build to two or three rounds over a few weeks. Switch to the harder options once the full routine feels easy. Keep each move slow and breathe normally throughout.

Short on time? Do just the dead bug and the side plank. For the dead bug, lie on your back. Bend your hips and knees to 90 degrees. Reach both arms toward the ceiling. Lower one arm and the opposite leg slowly toward the floor. Don't let your lower back arch. Then switch sides. Start the side plank by propping yourself on one forearm. Push your hips up until your body forms a straight line from head to feet. If you're starting out, rest on your knees instead of your feet.

The Diet Math: Calories and Protein for Visible Abs

Training builds and strengthens the muscle, but losing fat is what lets it show, and food drives fat loss more than mileage does. In the American College of Sports Medicine's review, 150 to 250 minutes a week of moderate exercise produced only modest weight loss (ACSM position stand).

Calories. Aim for a small, steady deficit rather than a crash diet. The CDC notes that people who lose about 1 to 2 pounds a week are more likely to keep it off. For athletes, slower can be better: in a study of elite athletes who also lifted weights, those losing about 0.7 percent of body weight a week gained lean mass, while those losing about 1.4 percent a week didn't (Garthe et al., 2011). For a 160-pound runner, 0.7 percent is about 1.1 pounds a week.

You may have heard that a 3,500-calorie deficit equals one pound of fat. Treat it as a rough shortcut. Researchers who tested it against real weight-loss studies found that it overestimates how much people actually lose (Thomas et al., 2013), so expect slower progress than the math suggests.

Protein. The Recommended Dietary Allowance (RDA) of 0.8 grams per kilogram of body weight isn't enough for people in training, according to the International Society of Sports Nutrition (ISSN). Its position stand recommends 1.4 to 2.0 grams per kilogram a day for most people who exercise, and notes that lifters may need 2.3 to 3.1 grams per kilogram to hold on to muscle while cutting calories (ISSN position stand). For a 150-pound (68 kg) runner, 1.4 to 2.0 grams per kilogram works out to about 95 to 136 grams a day.

As a rough guide, each of these counts as about 7 grams of protein: 1 ounce of meat, fish or poultry; one large egg; a quarter cup of tofu; or half a cup of cooked beans or lentils (MedlinePlus). Don't cut carbohydrates to make room for more protein. The same ISSN statement advises endurance athletes to focus on getting enough carbohydrate for performance. Does running build muscle? covers protein for runners in more detail.

Don't underfuel. Eating too little for the training you do can harm health and performance in women and men alike, a problem sports medicine calls Relative Energy Deficiency in Sport, or REDs (IOC consensus statement, 2023). Chasing very low body fat raises that risk. For context, ACE puts essential fat, the fat your body needs for basic functions, at 10 to 13 percent for women and 2 to 5 percent for men. If your energy, sleep or race times start slipping, ease off the deficit. Talk to a doctor or registered dietitian if things don't improve. Don't wait to get checked if your periods become irregular or stop, or if you get repeated stress fractures. Cleveland Clinic lists both as possible signs of REDs.

Spot reduction. Ab exercises are a poor way to burn belly fat. In a six-week trial, sedentary adults doing seven ab exercises five days a week improved their muscular endurance but showed no significant drop in abdominal fat (Vispute et al., 2011). One small 2023 trial in overweight men found slightly more trunk fat loss when nearly an hour of weighted ab work was added to a shorter treadmill run, four days a week, than with treadmill running alone (Brobakken et al., 2023), so the question isn't fully settled. For most runners, overall fat loss is still what reveals the abs. Does running burn fat? explains how running fits in, and why runners tend to be lean covers the bigger picture of how running reshapes body composition over time.

How Long Until You See Results?

Core strength and endurance usually improve before anything changes in the mirror. In one trial, athletes who added three core sessions a week held a plank-style test about 25 percent longer after eight weeks (Hung et al., 2019). In the six-week ab trial above, the exercise group also beat the control group on a curl-up test.

Visible change depends on how much fat you need to lose. ACE offers a simple formula: goal weight = lean body weight ÷ (1 − goal body fat percentage), assuming all the weight you lose is fat. For example, a 170-pound male runner at 20 percent body fat has 136 pounds of lean mass. Reaching 12 percent means weighing about 154.5 pounds, or losing roughly 15 pounds of fat. At about 1 pound a week, that's close to four months. Women should use a higher target: 12 percent falls inside ACE's essential-fat range for women, and its athlete range for women starts at 14 percent.

Progress is rarely that tidy in real life. ACE notes that most experts consider losing about 1 percent body fat a month safe and doable. That would stretch the same example to around eight months. Readings from calipers and body-fat scales carry enough error that small changes can be noise. ACE suggests waiting a couple of months between checks. Think in months, not weeks. Cutting calories harder isn't a shortcut. In the athlete study above, the faster weight loss came without the lean-mass gain the slower group saw.

A Strong Core Isn't the Same as a Visible One

Strength and visibility don't share the same cause. Treating them as separate goals helps.

What you see as a six-pack is your rectus abdominis. It's a long muscle that runs down the front of your stomach. The external obliques frame it along your sides. The deep transverse abdominis and the muscles along your spine do much of the stabilizing on a run. They aren't part of the six-pack you see. You can have visible abs from low body fat with an undertrained deep core, or a strong core with no visible definition at all.

For running, strength is what counts, though the evidence that core training improves running is modest. Running form can change as you tire: in one fatigue test, novice runners' peak forward lean increased by about 4 degrees (Koblbauer et al., 2014). Small trials have linked core training to faster 5,000-meter (5K) times in recreational runners (Sato and Mokha, 2009) and to slightly better running economy in college athletes (Hung et al., 2019), but neither showed exactly why. Core work is quick and may help your running, even if it never shows in the mirror.

Where to begin? The runner-type table above has your answer. Steady-state runners can start by adding the weekly speed session. Runners already doing speedwork will likely see the biggest return from the diet changes.

Frequently asked questions

Why don't I have visible abs even though I run a lot?

The usual reason is body fat rather than effort. Running trains your core and burns calories. Abs show up only once the fat layer over them is thin enough. Where your body stores fat is also influenced by genetics. There's no proven cutoff. ACE lists 6 to 13 percent body fat for male athletes and 14 to 20 percent for female athletes. Extra miles alone move that number less than diet and overall training do.

Do I need to do ab exercises if I already run?

They're not strictly needed, but they help. Running trains your trunk muscles mainly as stabilizers. One study found it works the obliques less than curl-ups do. Two to three times a week, do a short core routine. That adds direct work on the muscle you see. It can improve core endurance within six to eight weeks. Ab work does little to burn the fat over those muscles, though.

Does running flatten your stomach?

Running can help flatten your stomach by lowering overall body fat. It works especially well alongside diet changes. A visible six-pack is a different goal. A flatter stomach mostly comes from less fat on your midsection. Visible abs also need enough muscle underneath to show up. Running helps more with the first than the second.

Is sprinting or steady running better for building abs?

Faster running asks more of your abs because abdominal muscle activity rises with speed. Interval training may also trim slightly more fat than steady running. Both lower body fat percentage by similar amounts, though. Neither replaces direct core work. Start with relaxed strides before sprints if fast running is new to you.

How many days a week should I do core work as a runner?

Most runners do fine with two to three short sessions a week. Start with one round of each exercise. As the routine gets easier, build to two or three rounds. Adding more days isn't the goal. Short regular sessions are easier to keep up than one long session every so often.

Can I get visible abs from running without changing my diet?

It's unlikely for most runners. The American College of Sports Medicine's review found only modest weight loss from 150 to 250 minutes a week of moderate exercise. Running burns calories and core work builds the muscle, but what you eat is usually the bigger lever for making abs visible.

Is it safe to run in a calorie deficit while training for a race?

A small deficit is usually manageable during easy or base training. A large one during hard race training can hurt performance. It can also hurt recovery and health. Take weight loss slowly. Athletes losing about 0.7 percent of body weight a week kept and even gained lean mass in one study. Keep your carbohydrate intake up for hard sessions. Ease off the deficit if your energy, sleep or times start slipping. See a doctor or registered dietitian if that doesn't help. Don't delay if your periods become irregular or stop, or if you get repeated stress fractures.

Alex Gorovenko

I completed my first 10K on a dare. In a year, I ran a half-marathon. Another year later, I finished a marathon race. Today I run 4 marathons a year and a half-marathon every week. I learned everything about running the hard way. So, I help runners achieve better results easier.