17 most common workout mistakes that may be derailing your fitness gains

Seven PT's share the simplest ways to make the most of your sweat sessions.

Workout mistakes: Exhausted black athlete watching video
(Image credit: Getty Images/Cavan Images RF)

Seven PT's share the simplest ways to make the most of your sweat sessions.

The start of the new year means a return to working out or a new fitness routine for many. Not been to a gym class for yonks or just keen to avoid the basic no-no's that'll slow down your progress? We've asked seven experts - think PT's and run coaches - to share the most common workout mistakes they see on the gym floor and in training day-to-day.

Why? Not to put you off or highlight your errors, but to educate you on the simple tweaks you could make to your routine that'll make all the difference to your fitness gains. 

If you're experiencing gym anxiety or feeling your exercise motivation dwindling already, don't worry: that's totally normal after nearly two years of restrictions and home workouts. Many took the time to slow down, embrace self love and mindfulness tools like meditation to help deal with the stress of the pandemic - which also may mean that heading back to the gym now might feel like starting from scratch.

To help you on your way, keep reading as the experts outline the most common workout mistakes people make when exercising.

Workout mistakes: 17 easy to make mistakes

1. Not having a specific goal in mind

According to Martena David, personal trainer at Gymbox, having no goal in mind means you have no real structure to your workout or training.

"Get very clear and very specific about what you want to achieve," she recommends. "If you want to lose weight - how much? Or if you're keen to get strong - what does strong look like to you? Achieving a pull up, a push up, or lifting a certain amount of weight?"

A bit like life goals, having a specific workout goal in mind that’s realistic for you, and setting a specific time frame to achieve it in allows you to structure your workouts. "It'll also help keep you motivated and focused on your goal and training," the PT shares.

Workout mistakes: Side view of Young Asian women athlete running or jogging on treadmill in a hotel sport club

2. Training without a plan

Similarly, going on a run or to the gym without a plan leaves too much room for you to talk yourself out of it. Gym motivation can be hard at the best of times, so physically booking yourself onto a workout class where an instructor tells you what to do, or downloading a fitness app that logs your week-by-week progress may be the structure you need to keep focused, shares David.

"The gym can already be an intimidating space, so going in with no plan only adds fuel to the fire," she explains. "Following a plan or booking specific workouts eliminates any stress and pressure, and helps you to stay focused, too."

Got it?

3. Doing too much, too soon

Personal trainer and run coach Lillie Bleasdale of PASSA reckons that trying to make up for lost time in the gym is a recipe for disaster. Sure, our deep dive into the world of celebrity workouts found out that Adele loves an intense pilates sesh and J-Lo's a sucker for a high-intensity intervals circuit, but what works for others (read: the A-list) doesn't necessarily have to work for you.

"Don't try and bash out a workout every day on your first week back," she warns. "Instead, focus on quality rather than quantity to ensure that you gain results from the workouts you're doing." If you skip workout recovery, you'll only end up with delayed onset muscle soreness, aka stiff, achey legs from overuse.

Wondering how often you should be training? According to the PT, it's dependant on your goal, but you should be looking to train between three and five times, building up from a few times if you haven't been for a while.

Workout mistakes: Mixed Race woman sitting on bed meditating

4. Not taking enough rest days

Sounds counterintuitive, right? Taking more rest days to get your fitness levels back up again? But seriously: you have to rest to be able to push.

"Pushing through lethargy and not listening to your body is a no-no," shares Bleasdale. "Day-to-day life is a stressor on the body, and if your body is telling you you need some R&R, it's important to do so to stay injury-free and allow you to push your body further."

5. Practicing incorrect form

Sure, nailing the right exercise technique might seem daunting, but trust the experts here: you'll want to get it right to avoid risk of injury in the long term.

"Technique, form and posture are key to pretty much all forms of exercise," explains Lisa-Jane Holmes, Boom Cycle and Apex Instructor. "Technique is absolutely key to maximise effectiveness and see results over time, as once you're engaging the correct muscles, you can start to perform them to a higher intensity, or with more weight, which in turn will help you progress on your fitness journey," she explains.

Try this: either attend a workout class - there, the PT teaching will correct your form and help you learn the need-to-knows - book a PT session (or just ask a PT in your gym, if you can't afford one), or check out the many form videos on YouTube. While these aren't a replacement from learning from someone IRL, they're a great way to cover the basics.

6. Forgetting to mix it up

Consistency is great when it comes to fitness, but doing the same thing every single time you workout will eventually mean you plateau and stop seeing the results, explains Holmes.

"An ideal exercise regime will combine cardio, resistance and flexibility work so that you can improve cardiovascular endurance, build strength, change your body composition (reducing fat but gaining muscle) and improve range of movement," she shares.

Young woman folding yoga mat after class end

7. Aiming for quantity over quality

Barrecore head teacher Emily King again reinforces that everyone makes workout mistakes, but that one of the worst is trying to do too much, rather than focusing on the quality of your workouts.

"We often think the more we do something the better, but when it comes to fitness, this isn’t always true," she explains. As above, aim for three to five workouts a week but make sure that you go into them ready to give your all. You're all set.

8. Forgetting to warm up

We get it - warming up isn't exactly exciting, but as KOBOX trainer Maria Binns explains, if you're going to do a tough workout, you absolutely have to prep your body.

"Warm-ups are important not only to warm your muscles and prevent injury, but also to activate them in order to get the most out of your session," she shares.

New Balance run coach Johnny Mellor agrees, sharing that he often sees runners skipping a warm-up. "Take time to ease into runs and, if you have time, perform some basic dynamic stretching and mobility exercises prior to heading out of the door," he advises.

9. Ignoring pain

We’re all guilty of ignoring pain when working out - for some, the whole point of working out is pushing yourself and your body. However, it’s super important to learn the difference between workout pain, a small niggle, and something more serious, stresses Mellor.

"One of the biggest workout mistakes you can make is not listening to your body and only resting when you feel sore," he shares.

Exercise errors: Over the shoulder view of a young woman wearing smart watch, using fitness app to check her training progress

10. Forgetting to refuel

Workout mistakes are easy to make, but this one's especially important for runners.

"It’s important to refuel within the 30-minute glycemic window to replenish glycogen stores and help kick start the recovery process," explains Mellor.

Similarly, if you're weight training, consuming a portion of protein post-session can be a good way to repair your muscles and prevent DOMs. Our guides to the best protein powders for women and what to eat after a workout should help.

11. Not applying progressive overload

This is a big one, or so says David. "If you're weight training, you'll need to be progressively overloading your lifts and exercises," she shares.

Try this: aim for small progressions each week, whether that’s adding a little extra weight, trying an extra set, nailing an extra rep, reducing your rest periods or intensifying your training.

"Once you are comfortable with an exercise or movement, make sure you challenge yourself by progressing, too," she shares.

12. Not tracking your workouts

A lot of us forget what we ate for breakfast let alone what we did last week in the gym. Right? A great way to make sure you stay on track with your training is by tracking your sessions, shares David.

"Without a record, you’re essentially just guessing and limiting your own progress," she explains.

Exercise mistakes: Woman holding small dumbbells at gym

13. Not getting enough sleep

FYI, sleep is one of the most productive things you can do with your time both physically and mentally.

"When we sleep, we recover and grow," Mellor explains,. Try this: hit the hay 15 minutes early every day. Going to bed just that little bit earlier each night soon adds up.

Or, read our guides to insomnia treatment and how to get to sleep for more expert tips on getting enough zzz.

14. Comparing yourself to others

Finding yourself getting caught up in Strava and social media and worrying about what other people might be thinking?

Remember this: you don’t know what journey they’re on. "It’s important to control what you can control - that being yourself," stresses Mellor.

15. Don't lift weights that are too heavy

Ever tried to pick up a dumbbell that's, like, 5kg too heavy for you and nearly strained your back in the process? Yep, you're not alone. VAHA personal trainer Allie Williams' top gym mistake to avoid is opting for weights that are too heavy for you.

"Sure, it's great to push yourself to new limits, but lifting weights that are too heavy, too early, can do more damage than good," she explains.

Try this: Increase your weights slowly and consult experts for advice on hitting your goals. Our expert-led guide to weight training for ladies might help.

Workout mistakes: Women relaxing together in gym

16. Remember to activate your glutes and hamstrings

This links back to our point about making sure you're practicing correct form. "Making sure you're engaging your muscles correctly will allow a more effective workout overall," she explains.

Try this: Williams recommends thinking about exactly what muscle group you're working on before practicing any workout move, and always remembering to tuck your pelvis under before carrying out any glute movements.

17. Always ask for help, if you're unsure

Last but by no means least, it's important to remember that PTs and instructors are there for a reason.

"From teaching you how to weight train properly, to correcting your downward dog technique, to perfecting your glute bridges, they're experts at what they do and will have all the tips and advice to help you meet your goals," Williams explains.

Ally Head
Senior Health, Sustainability and Relationships Editor

Ally Head is Marie Claire UK's Senior Health, Sustainability, and Relationships Editor, nine-time marathoner, and Boston Qualifying runner. Day-to-day, she works across site strategy, features, and e-commerce, reporting on the latest health updates, writing the must-read health and wellness content, and rounding up the genuinely sustainable and squat-proof gym leggings worth *adding to basket*. She's won a BSME for her sustainability work, regularly hosts panels and presents for events like the Sustainability Awards, and is a stickler for a strong stat, too, seeing over nine million total impressions on the January 2023 Wellness Issue she oversaw. Follow Ally on Instagram for more or get in touch.