Work out smarter, not necessarily harder.

That’s the logic behind metabolic assessments.

Common among elite and Olympic athletes, the cardio-based test is becoming more accessible to everyday gym-goers looking to lose a few stubborn pounds or improve their performance.

A metabolic assessment can help create a personalized workout routine based on your own body chemistry. It typically measures your resting, or basal, metabolic rate (how many calories you burn at rest) and your active metabolic rate (how many you burn in a day). Based on your heart rate, it can pinpoint at which zone you stop burning the most calories from fat (good for weight loss) and start burning more calories from carbohydrates (bad for weight loss) — as well as tell you how many calories you should eat in a day to maintain, lose or gain weight.

“We have a really predictable, scientific way of telling you when that four pounds will be gone, and when you’ll see that six-pack, or fit into the dress, or lose a belt size, whatever it is,” said David Barton, of David Barton Gym fame. “We can really pinpoint the date at which you’ll have achieved that result. I think that’s something that’s really valuable for people.”

At TMPL, Barton’s newest gym, members can get a digital metabolic profile that, through various technology, can also measure their body fat and lean muscle, provide weekly 3D images of their body, stimulate fat loss and more. The assessment also includes a questionnaire developed with wellness expert Jim LaValle, the “father of the metabolic assessment,” Barton said, that can help identify issues with their metabolism. From there, members can also elect for personal training sessions based on their results and goals.

The assessment, which starts at $149, has been so popular there’s a waiting list, and the 6-month-old Hell’s Kitchen gym is training more people to answer the demand.

“What we’re doing is a service that, up until now, was really available only to elite athletes,” Barton said. “Being able to create programs for exercise and nutrition that coincide with the person’s individual metabolism is something that’s been really hard to come by until now.”

The 2-month-old luxe gym Life Time Athletic at the Sky residential building in Hell’s Kitchen offers metabolic assessments done by a team of nutritionists and trainers.

“One size doesn’t fit for everybody’s body,” said Allyse Mickol, nutrition coordinator for Life Time Athletic at Sky. “We like to run different assessments to see what’s going on internally. You can’t give a blanket statement to everyone.”

Life Time’s assessment uses a machine to measure a person’s resting metabolic rate, and then you’re running on a treadmill so it can look at your different heart rate zones, see at which point your body is burning fat or carbs and determine what heart rate you want to reach during a workout.

“It’s finding that specific zone for each person,” Mickol said. “You’re always using a heart rate monitor so you’re getting the most efficient workout possible. You want to train smarter, you don’t have to necessarily train harder.”

Kate Edmundson decided to get the metabolic assessment done at Life Time to try to lose a few pounds and get leaner.

“I didn’t really have a program before,” said Edmundson, 28, a fashion designer who lives in the Sky. “I actually found out that my heart rate needs to be lower than I thought it would be to burn more fat.”

After following a four-week cardio program, as well as adjusting her diet to limit carbs and alcohol and eat more lean protein, she lost seven pounds.

“For the first time in probably three years I actually lost weight. ... I have a lot more energy,” Edmundson said. “For anyone looking to tone down or lose weight, I think the metabolic assessment is great, just so you know where you should start.”

Life Time’s service is open to members and nonmembers and costs $259 for the active metabolic assessment and $144 for the resting metabolic assessment.

“It can really be for anybody,” Mickol said. “I use it a lot on my weight-loss clients. It’s also good for people who are trying to improve their time or reach a marathon goal. Everyone I find has a place for it.”