It’s January. Which may mean virtually everyone you know has embarked on an intense fitness or nutrition routine that they’ll probably abandon by February — if they haven’t already. Kim Kardashian, predictably, is no exception. Earlier this month, she shared that she and sister Khloe were embarking on a “sister bootcamp”: 30 days of intense twice-daily workouts, and a structured plant-based diet.

Of course, Kim has the benefit of an army of trainers, chefs, nutritionists, and assistants to help her stick with her plan. Still, when faced with her intense routine, it’s easy to start feeling lazy for working out just once a day (or not at all). If you’re in that boat, read on, because experts say for most people, two-a-day workouts are simply not necessary. And if you’re feeling stressed or tired? Multiple intense workouts in a day are an extra-bad idea.

What are two-a-day workouts?

Well, exactly what they sound like: doing two workouts in a day, usually separated by a number of hours. And we’re not talking about going for two brisk walks in a day. Often, one workout in a two-a-day is a strength-focused session, while the other is a cardio or conditioning workout. Other times, they might both be strength sessions focused on different parts of the body, for instance, upper body and lower body.

There are a couple reasons people adopt this workout style. “People who chose to train two-a-day workouts are typically trying to look a certain way by a certain date or are looking to be in optimal shape for peak performance,” explains Kristina Jennings, CFSC, a performance coach with Future.

In other words, it’s usually people who get paid to look or perform a certain way who benefit from this workout schedule. Think: Professional athletes, bodybuilders, celebrities, and models. School sports teams often use this strategy as well, points out Pamela Geisel, MS, CSCS, exercise physiologist at HSS. Thing is, in all of these scenarios, two-a-days are done under the supervision of coaches, clinicians, and/or physical therapists. It’s their job to ensure their athletes or clients don’t get hurt or exhausted.

Umm… why do people do this to themselves?

The main reason is to get results in a shorter period of time, says Andrew Watkins, a performance enhancement specialist and head of strength and conditioning at Sports Performance Lab. For an athlete, that might mean developing baseline cardiovascular fitness faster when they come back from their off-season. For a celebrity, it could mean they only have to spend eight weeks preparing for a movie role instead of 12.

For the average person who wants to get fitter, that might sound appealing. Problem is...

There are some downsides to two-a-days.

Some cons of working out at a high intensity twice a day, according to Watkins, include increased risk of overtraining, injury, workout burnout, poor sleep, and inadequate recovery. You might even run down your immune system if you really overdo it, he adds.

That’s why, in general, Geisel doesn’t recommend hardcore two-a-days for the average person looking to improve their fitness. “Any bout of exercise is a dose of stress on the body,” she explains. Usually, the stress we experience from workouts is actually a positive thing that helps us get stronger. “However, too much exercise or too many other stressors (work hours, personal distress, new baby, new puppy, financial struggles, an upcoming move, etc.) tip the scale the other way and result in burnout or injury,” she says. Especially considering the times we’re living in, more stress is often not a good thing.

Instead of working out twice a day, Geisel prefers her clients focus on getting in one quality workout that makes sense for their life, rather than exercising more frequently to burn more calories or earn active minutes.

What to keep in mind before you try two-a-days:

Of course, there are always exceptions. If you’re really intent on doing two-a-day workouts, there are some scenarios where it might make sense, and some ways to make it safer.

“If someone works a desk job for 10 hours a day, they could benefit from an AM strength session and a PM cardio or mobility session, since they may simply not be moving enough during the day,” Geisel says. If that sounds like you, here’s what to know before you get started.

Be honest with yourself. “Have you maximized your current training program?” Watkins asks. If you’re not working out consistently already, increasing to two workouts per day probably doesn’t make much sense. Forty-five to 60 minutes once a day is more than enough time to have a great workout, Watkins says.

Start with just one day a week, and keep it low-key. Pick a moderate- to high-intensity workout earlier in the day, and then perform a lower intensity workout later in the day, Geisel advises. For example, you could do a bootcamp workout in the morning, and a restorative yoga class or 30-minute walk in the evening. “In between, be sure to refuel and hydrate appropriately.” In other words, drink some water and eat a lunch that makes you feel satiated.

Make sure you’re recovering. “One reason celebrities and athletes can maintain this lifestyle is because they have more opportunity and resources to recover properly,” Watkins says. “When you work a 9-to-5 and have family responsibilities, it can be a slippery slope. Eventually, something is going to break, and in most scenarios, it’s our minds that break down before our bodies.” His advice? If you really want to work out twice a day, make sure you consistently get eight hours of sleep, and consider consulting a nutrition professional to ensure you’re getting adequate nutrients.

Know your “why.” “Oftentimes, people are just doing workouts that they find fun without any structure or program in place,” Geisel says. That’s fine, but if you’re serious enough to be working out twice a day, you want to be clear on what purpose you hope to achieve with your workouts and how you’ll get there.

Consider working with a qualified coach. This can help with understanding your goal and developing a solid plan to get there safely.

Don’t use celeb social media for workout inspo. We all know that what we present on social media is usually an edited version of what’s really happening in our lives. Celebrity and fitness posts are no exception. “Anyone can portray themselves as knowledgeable on the internet as long as they look good in spandex,” Geisel points out. “You never know what else is going on ‘behind the scenes.'”