Kayla Itsines’ BBG workouts transformed my body — here’s how they work

a photo of kayla itsines and fitness editor jane mcguire
(Image credit: Instagram/KaylaItsines/Janecmcguire)

I’m not exaggerating when I said Kayla Itsines’ BBG workouts changed my life. I discovered them when I was in my early twenties, fresh out of college and I was unhappy with my body. I’d suffered from an eating disorder for most of my teens and had spent the past few years like many students do — eating and drinking what I wanted, without much concern about my health. I followed Australian trainer, Kayla on Instagram, and, at the time, it seemed like all of the girls in my work gym were following her Bikini Body Guide (BBG) workouts, so I bought the 12-week course, downloaded the PDF (welcome to the world of fitness before the best workout apps were invented), and got going. 

What happened next was incredible. Not only did I completely transform my body — I don’t weigh myself since my eating disorder and still don’t to this day, but I still have the ‘transformation’ photos on my phone, and I definitely dropped a dress size and shaped up, but the BBG workouts gave me confidence. I felt better about myself, and stronger in the gym. I didn’t just spend hours running on the treadmill, I followed a schedule of 2-3 resistance workouts a week, a couple of 30-minute LISS workouts (low-intensity steady state: think walking or cycling), and as the weeks progressed, a couple of HIIT sessions (Kayla recommended interval sprints on a treadmill, bike, or rower). On paper, it looked like a lot, but the 28-minute workouts were short and snappy, and it didn’t take long for me to see results. 

Nearly ten years later, I still have that PDF saved to my phone, and I still turn to the 28-minute workouts when I’m looking to mix up my routine. We’ve both changed — Kayla rebranded her BBG workouts when the fitness industry started to shy away from terms like ‘bikini body’, and rebranded as Sweat in 2017 (here’s my review of her Sweat app). I’ve now run four marathons, and work as a fitness editor, and while it would be a bit of an over-exaggeration to thank Kayla for the aforementioned, her workouts definitely made me fall in love with fitness all those years ago.  

Here’s what I learned from nearly 10 years of BBG workouts

The workouts work

There’s a reason why an Instagram account named ‘bbg.inspos’ has nearly 40,000 followers, and a hashtag #bbgtransformations has hundreds of thousands of posts — the workout program works.

On paper, it looks like a lot, but the 28-minute workouts are fast. You do two 7-minute circuits twice, with a 30-90 second break between each circuit if you need it. The number and intensity of the workouts increase the further you get into the program, but the idea is, the entire workout can be done in 30 minutes.

Plus, while we’re talking about transformations, it’s important to note that according to Kayla herself, a ‘bikini body’ isn’t a certain weight or size, it’s when a woman feels comfortable and confident. 

I’d probably have noticed more of a transformation if I’d also followed the eating plan

As I mentioned above, I’ve always had a funny relationship with food. For the past 10 years, I’ve never allowed myself to restrict any food groups, although I do follow a gluten-free, vegetarian diet. I don’t follow strict meal plans, but I do generally eat healthy foods. 

There are no ifs or buts about it — you can’t out-exercise a bad diet, and you won’t get visible abs unless you have a low body fat percentage (here’s how to calculate your body fat percentage, and why it matters). The BBG program comes with a meal plan, and you’ll be able to find the same on the Sweat app today. I’m sure I’d have had better results following a high-protein diet, but for the reasons already mentioned, I didn’t use this part of the program. 

The variety makes it interesting

I was a complete beginner when I started this program, yet I have returned to it many times since, with a lot more experience in the gym. In fact, I re-started the program from scratch in lockdown, when I was forced to do most of my exercise at home. The variety of workouts helps keep you motivated and prevents you from having too much time to get bored in the gym. 

Things have come a long way, and the Sweat app now has loads of different workouts to follow, including those suited to those working out at home, with zero equipment, or those who prefer to be in a gym. Either way, it’s worth mentioning that if you are completely new to exercise, it’s a good idea to ask a personal trainer to check your form, to avoid putting yourself at risk of injury. 

How to try a BBG workout 

Ready to give it a go? The easiest way to do so is to download the Sweat app, which is cleverly designed to time your workouts for you — no more setting 7-minute timers on your phone. But if you’re looking for a free taster, here’s an equipment-free BBG-style workout Kayla did with Women’s Health: 

Looking for more workout inspiration? Read what happened when this fitness writer did 80 sprawls every day, a 25-minute workout that targets your glutes with zero equipment, plus this 10-minute kettlebell ab workout.   

Jane McGuire
Fitness editor

Jane McGuire is Tom's Guide's Fitness editor, which means she looks after everything fitness related - from running gear to yoga mats. An avid runner, Jane has tested and reviewed fitness products for the past five years, so knows what to look for when finding a good running watch or a pair of shorts with pockets big enough for your smartphone. When she's not pounding the pavements, you'll find Jane striding round the Surrey Hills, taking far too many photos of her puppy.