Striving for abs? 15 things a PT wants you to know before you waste your time on the wrong things

For millennia, having visible abs has long been treated as the ultimate holy grail of fitness – and for some, an impossible-to-achieve beauty standard. But here in the modern wellness world, we know that looking shredded does not automatically equate to being healthy and that working out offers a myriad of incredible benefits that are worth your time too (from boosting your mental health to protecting your joints). Y'know, stuff that goes beyond getting a lean midsection.

However, that doesn’t mean you shouldn’t strive for defined abs if that’s your goal... but it does mean understanding what’s truly required, what’s realistic and what’s worth prioritising.

To help you get there safely, sustainably and ideally without losing your mind, we overhauled the advice of fitness expert and PT James Stirling (aka London Fitness Guy).

Here’s what to know before you set your sights on a six-pack…

1. There’s no shortcut (sorry)

Spoiler alert: there is no magic tea or complicated biohacking routine that can give you the abs of your dreams. According to Stirling, building core definition comes down to a very simple trio:

• Strength training: To build the muscle itself.
• Core-specific exercises: To target and strengthen the abdominal wall.
• A calorie deficit: To reduce overall body fat so the muscle underneath actually shows.

2. You need to build muscle – not just ‘tone’

The saying ‘abs are made in the kitchen’ is only half the story, says Stirling. Yes, body fat needs to be low enough for definition to show, but you also need actual muscle underneath. Without that, you’re just becoming a smaller version of your current shape.

Treat your core like you would your glutes or biceps: use progressive overload (gradually increasing the weight or difficulty) to make those abdominal muscles grow.

3. Core exercises still matter

Planks, crunches and leg raises won’t magically give you visible abs, but they are essential for building strength and muscle in your core. Oh, and they don’t get easier (sorry). A strong core will always be challenged by well-executed basics! "If I did 50 crunches now I would still feel it in my core like I did before years of training" laughs Stirling.

4. Compound movements are key

While you might think of crunches as the ultimate ab workout, heavy compound movements, like squats, deadlifts, and even the leg press, also demand intense core stability. "You need to control and contract your core during those compound and dynamic movements," Stirling advises.

Note: Always seek the advice of a qualified PT if you're new to lifting heavy weights!

5. Your living room is a totally valid gym

Gym anxiety? No problem. The core is one of the easiest muscle groups to train from the comfort of your own home. You don't need fancy cable machines; a yoga mat and your own body weight are more than enough. As long as you are actively focusing on contracting the muscles during the movement, you'll see progress.

6. You can't out-crunch a calorie surplus

You could have the strongest, most developed abdominal muscles in the world, but if your overall body fat percentage is too high, they simply won't be visible. To see definition, you have to be in a gentle calorie deficit (meaning you burn more than you consume). Once your overall body fat reduces, the muscles you've built underneath will start to peek through.

7. Calorie counting doesn't have to be obsessive

Being in a calorie deficit requires an awareness of what you're eating, but it absolutely doesn't mean you have to log every single leaf of spinach into an app for the rest of your life. Stirling often advises clients to track their food for just one week as an educational exercise. Once you understand your baseline, you can focus on building balanced plates (protein, complex carbs, healthy fats, and veggies) intuitively.

Stirling says he recommends that some clients just track for a week as more of an educational exercise, so they're aware of what they are eating in their daily meals, and whether they're getting the right amount of protein, carbohydrates and fats for their goals, then tweaking the diet accordingly. He advises structuring each meal as a healthy balance of proteins, carbohydrates, vegetables and fats, as a way to gage if you're eating for abs.

8. Please, do not cut carbs

Let’s leave the intense anti-carb rhetoric in the past where it belongs. "Low carb only really works because you are taking carbs off the plate and reducing the total amount of calories," says Stirling. If you're strength training, carbohydrates are essential for fueling your workouts and helping your muscles recover. You can absolutely eat pasta and still hit your goals.

9. Margaritas and biscuits can still stay

If a fitness plan requires you to cancel all your dinner plans and never look at a biscuit again, it's not a sustainable plan. The trick is moderation, people! Aim for a really solid, nutrient-dense routine Monday through Friday so you can genuinely enjoy your weekend without guilt.

You don't have to quit drinking, but be mindful of the frequency and the calories in your mixers. Equally, sugar is fine in moderation; one Krispy Kreme won't derail your progress, just as one salad won't give you a six-pack. Consistency is what matters.

10. Cardio is optional – not mandatory

You don’t need endless cardio sessions to get abs. It can help create a calorie deficit, Stirling points out, but it’s just one tool. Overdoing it often leads to burnout rather than results. “For me personally, I would only add cardio if I had started to see a plateau, and then maybe tweak the diet – otherwise you don’t have a lot to play with, and you end up in a position where you aren’t seeing the results you want because you hammered everything too soon."

11. But doing your daily steps is a non-negotiable

While intense cardio isn't strictly necessary, NEAT (Non-Exercise Activity Thermogenesis) aka your daily movement, is massively underrated for fat loss. Simply walking more, getting off the bus one stop early, or pacing while on the phone burns a significant amount of energy over the course of a week.

12. Stressed out? Your workouts could be backfiring

"Fat loss is so strange," says Stirling. "There are so many factors that can contribute to it stopping, mainly stress and cortisol levels. So if you're over-training or you aren't getting enough sleep, it can hinder your fat loss." The PT monitors his sleep quality and length using his Fitbit app to make sure he's rested enough, but says there are other signs you might need to take a break too.

"If you're feeling burnt out and demotivated and physically not performing how you think you can, you are probably doing too much, so should be sensibly reining it in and give yourself a rest day or even a rest week or a break from your diet – this is when your muscle growth happens – and helps with your performance too."

Stirling adds that it's better to spend a shorter time in the gym, but be efficient and work to the max in your sessions. "I changed my philosophy [a few years ago], rather than spending an hour, or 90 minutes in the gym, I now spend 45 minutes but have a really good workout."

13. Maintaining abs isn’t always realistic

Achieving visible abs is one thing; staying that lean year-round is another. For many women, dropping to the low body fat percentage required to maintain a visible six-pack can negatively impact hormonal health and even stop your menstrual cycle. “If your fat loss mission is starting to negatively impact your life and plans to see your friends, it's becoming a dark place to be in and you need to reassess your goals,” says Stirling. Focus on how energized and strong you feel, rather than obsessing over staying at a specific body fat percentage forever.

14. Abs aren’t a measure of health

If your pursuit of fat loss is making you miserable, causing you to isolate yourself from friends, or triggering obsessive thoughts about food, it is time to immediately reassess. Visible abs are just one tiny fraction of the fitness picture. Shift your goals toward getting stronger, improving your endurance, or simply moving for the joy of it.

15. There’s no fixed timeline

Forget ‘six-week abs' promises. How long it takes depends on your starting point, your lifestyle, and how aggressive you’re willing (or able) to be. Faster isn’t always better, or sustainable.

This article is not intended to be a substitute for professional medical advice or diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Lauren Smith

Head of Social

Lauren Smith is Cosmopolitan UK's Head of Social, and looks after the site's social media accounts, as well as occasionally covering fitness, health,  lifestyle, and travel on the site. She lives in London, and likes fitness, porridge, peanut butter and her cat Theo.