Whether you’re a seasoned gym-goer or just getting started, there’s a good chance you’ve picked up a habit or two that’s working against you. Personal trainers spend their days watching people work out, which means they’ve seen it all and know what’s inadvisable. “As a certified personal trainer, there are several habits I consciously avoid both for my own well-being and also out of respect for other gym-goers and overall safety,” Mallory Fox, a National Academy of Sports Medicine master trainer and wellness coach, told HuffPost.From skipping warm-ups to mindlessly scrolling between sets, there are many ways people can better work toward their long-term fitness goals and create a positive environment while doing it. Below, find 15 things personal trainers never do at the gym.1. They don’t skip the warm-up.“Many people like to just jump right into their workouts,” said Denise Chakoian, a certified fitness trainer and owner of Core Cycle and Fitness LaGree. “They walk in, grab the heaviest weight they can find and start swinging away. Or they hop on the treadmill and crank the speed dial to 10. Sure, there’s something to be said about getting your heart rate up, but warming up properly is so important.”She recommended five to 10 minutes of dynamic movement before jumping into your regular workouts to help activate your muscles, improve mobility and reduce injury risk.“I would never skip my warm-up, especially as a woman approaching midlife,” said certified personal trainer Tara De Leon. “I see this constantly, and it’s an easy way to get injured, particularly during a phase of life where the body starts playing by different rules. Longevity in training, and being consistent, matters way more than any single session.”2. They don’t hog gym equipment. “I would never monopolize equipment,” Fox said. “Whether it’s sitting on a bench while not using it or claiming multiple pieces of equipment, I’m very aware of sharing space. Gyms are communal environments, and consideration for that shared space goes a long way.”Show respect for people’s time and avoid hogging equipment, especially when the gym is crowded. “I would never take up multiple machines at the same time,” said Kelsey Holgate, a personal training leader and nutrition lead at Life Time Savage. “There are only limited amounts of machines, and that doesn’t allow people to use those machines.”3. They don’t judge others or offer unsolicited advice. “I would never judge someone else for how they train, what they lift, or where they are in their fitness journey,” Fox said. “Everyone starts somewhere, and the gym should be a space that feels supportive. As a certified personal trainer, I see how confidence impacts consistency, and negative or judgmental energy can discourage people from showing up at all.”She added that she also does not offer unsolicited advice and only intervenes if someone visibly needs help with something like a bench press or if they’re going against gym rules. She emphasized that respect and inclusivity go a long way toward building a positive gym culture. “I would never comment on someone’s body shape or size, even as a compliment,” De Leon said. “The gym can already feel like a vulnerable space for a lot of people and unsolicited body comments can reinforce the idea that bodies are there to be evaluated. I want people to feel strong, not judged.” 4. They don’t ignore pain.“There’s a big difference between the discomfort that comes with challenging yourself and actual pain that signals something isn’t right,” said WalkFit certified personal trainer David J. Sautter. “It’s very common to see people try to get back into the gym too soon while they’re still recovering or dealing with pain, and it rarely works out the way they hope. Pushing through an injury can set your progress back by weeks or even months.”The bottom line: Listen to your body and prioritize consistency rather than intensity.“I’m sure we’ve all heard the saying ‘no pain, no gain,’” Chakoian said. “I’m here to tell you that’s false. Muscles get tired, and they may burn a bit when you work out, but hurting yourself is not the way to achieve your goals. If you feel a sharp pain or pain that comes on suddenly, stop what you’re doing.”5. They don’t compare themselves to others. “Everyone has different goals, fitness levels, and life circumstances, so comparing yourself to others isn’t helpful,” Sautter said. “It’s important to focus on your own progress because what works for someone else may not be right for you. Comparing yourself to others often leads to frustration rather than improvement.”He noted that some people are focused on increasing daily step counts or cardio, with gym-based strength training as a way to support that goal.“I’d never compare my chapter one to someone else’s chapter 20,” said April Medrano, vice president of programming, education and experience at STRIDE Fitness. “The person next to you has their own history and their own path. Your only competition is who you were yesterday.” Frazao Studio Latino via Getty ImagesIt's important to listen to your body rather than work through sharp pain. Antonietta Vicario, chief training officer at PVOLVE, emphasized training progressively to slowly build on goals over time and consider what your individual body needs in your particular season of life. “Each person is on their own unique journey, and strength looks and feels different from person to person,” she said. “A one-size-fits-all approach at the gym just doesn’t take into account the myriad of factors that should influence how we show up at the gym and what types of movement we should prioritize.”6. They don’t work out without a plan. “I never work out without a plan,” said Joshua King, training lead at Life Time Gainesville. “If you don’t know what you’re trying to accomplish, it’s hard to measure progress.”You don’t want to go on autopilot and spend months doing the exact same thing with the exact same weights. Think about things like hitting different muscle groups and working strategically to hit failure. “Going to the gym without a plan is like getting in the car to go somewhere you’ve never been without a GPS. We need a clear path and structure to see results,” Vicario said. “We should ideally be hitting muscle failure three times per major muscle group in a session, and aiming to hit each major muscle group two times per week.”The body adapts, so you need to challenge yourself if you want results. “I wouldn’t do random workouts without intention,” Fox said. “I aim for every session I do to have a purpose, even if it’s active recovery or whether it’s strength, hypertrophy, conditioning or mood. Random programming leads to random results. Keep in mind, though, sometimes just moving the body to get into a better mindset also counts as an intention.”7. They don’t forget to wipe down and return equipment. “I’d never leave my weights scattered or benches sweaty,” Medrano said. “Re-rack, wipe down, reset. Basic respect for the people training around you.”These practices are not just good etiquette but good safety protocol as well. “In consideration of staff and members alike, I return equipment as I finish using it and wipe down everything as I go,” said Kat Pasle-Green, a health and fitness coach with Bay Club. “Gyms work best when we respect the shared environment and the people within it.”8. They don’t sacrifice form for weight.“I never sacrifice form to lift more weight,” said trainer and Karen Lord Pilates founder Karen Lord. “Progress isn’t measured by how much weight you move ― it’s measured by how well you move it. Poor mechanics might feed the ego today, but they often catch up with you later through injury or compensation.”Indeed, many trainers refer to using poor form to chase heavier weights as “ego lifting.”“It is one of the fastest ways to stall progress or get hurt,” Fox said. “I prioritize technique and control over load. Quality reps always beat sloppy ones.”Your body may pay the price for this bad habit. “Lifting heavier weights is great, but not at the cost of your health,” Chakoian said. “If you’re swinging the weights around, using too much momentum, rounding your back or sacrificing form in any way just to lift heavier, you’re only cheating yourself. Not only will you not get the results you’re hoping for, but you’re putting yourself at risk for injury.”9. They don’t talk on the phone.“I would never talk on my cell phone while sitting on a piece of equipment,” Holgate said. “It’s loud and annoying to a lot of people. We don’t need to hear about your drama or business meetings.”Even worse than chatting on the phone is broadcasting both sides of the conversation. “Don’t talk on speakerphone in the gym,” King said. “Nobody came to listen to your conversation.”10. They don’t push themselves if it doesn’t feel right. “You don’t have to force progressive overload every single week,” said certified personal trainer Josh Schlottman. “If you wake up feeling off or have a slight pain in your shoulder, then it’s best to back down the weight or change the exercise instead of forcing a heavy set just to try and beat last week’s numbers.”He stressed that forcing progression when your body isn’t ready is a solid way to get injured. “I would never treat every workout like a competition,” said Thomas Banicky, senior district fitness manager at 24 Hour Fitness. “Not every day is meant to be a personal-record day. Some days your body needs a lighter session, more mobility work or active recovery. Listening to your body is a key part of long-term fitness success.”AzmanL via Getty ImagesRest and recovery are as important as the actual working out. It’s all about being realistic and doing the things that allow you to be consistent, not at max intensity at all times. “Your body gets stronger during recovery, not just during training,” Lord said. “Some days should be about building capacity, others about maintaining it. Consistency beats intensity over time.”This mindset allows you to build a genuine love of exercise as a lifelong practice.“I would never treat a workout like a punishment,” De Leon said. “Exercise shouldn’t be a payment for eating food or penance for having a treat. The people who are successful at staying active for decades are the ones who find ways to enjoy the movement.”11. They don’t skip or restrict rest between sets. “I would never restrict my rest intervals just to get a ‘pump,‘” Schlottman said. “Traditional bodybuilding wisdom says to rest 60-90 seconds to maximize ‘metabolic stress’ and chase the pump. But science has debunked this.”He noted that metabolic stress doesn’t inherently cause muscle growth ― rather, mechanical tension does.“Resting longer, like three minutes, lets your neuromuscular system recover, lets you lift more weight for more reps,” Schlottman said. “This will create more total mechanical tension and will lead to way greater muscle growth and strength development.”12. They don’t lift heavy on unstable surfaces.“I would never lift heavy weights on unstable surfaces like Bosu balls,” Schlottman said. “Unstable surface training especially when lifting heavy weights is ineffective and potentially puts you at risk for an injury.”He added that unstable surfaces can also limit how much force you produce because your balance becomes the overriding factor. “If you want to build muscle, then you need high mechanical tension, and you can’t get that if you’re wobbling around on a rubber half-ball,” Schlottman explained. 13. They don’t mindlessly scroll between sets.“I see so many people mindlessly scrolling their phone between sets while others are waiting, and it often ends in a confrontation or bad vibes,” Fox said. “Rest is important, but being glued to the phone disrupts focus and flow, extends workouts unnecessarily, and can make equipment inaccessible for others.”She recommended keeping rest intentional and time-conscious. “During workouts I stay aware of the space I’m occupying and how movement flows around me, gladly letting someone work in when it’s practical,” Pasle-Green said. Consider your gym time a well-earned break from screens and chance to connect with your body in a communal space. “We all want to stay connected, but spending your whole workout texting isn’t good for your workout,” Chakoian said. “Take yourself away from your phone between sets and you’ll be surprised at how much more focused you are during your workout.”14. They don’t take fitness advice from just anyone. “I would never take advice just because someone has the biggest muscles,” King said. “Size doesn’t always equal knowledge. I value experience, education, and proven results. And don’t believe every fitness influencer. Social media rewards entertainment.”He touted the value of evidence and lived understanding of what consistently works. “I would never chase fitness trends without understanding the fundamentals,” Thomas Banicky said. “Social media can be a great source of inspiration, but consistency with basic movement patterns, strength training and cardiovascular exercise will always outperform the latest fitness fad.”15. They don’t forget to recover.“When most people think about working out, they think about how they can sweat the hardest or lift the most weight. But what most people don’t realize is that recovery is where the magic happens,” Chakoian said. “Getting enough sleep, staying hydrated, eating a nutrient-dense diet and taking rest days allows your body to rest and repair itself so you can see the results you’re looking for.”That’s why it’s important to not skip recovery work as part of your training process. Things like stretching and foam rolling can go a long way. “We need to be intentional about our recovery in order to see results,” Vicario said. “Your muscles need to rest and repair to build stronger, especially when you are incorporating training for hypertrophy. If hitting muscle failure, I give those muscle groups at least two days off before hitting them again as it is in the repair phase where they are actually build stronger. To this end, I alternate body focuses strategically to get the most of my workouts.”