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Student Loses 15KG While Increasing Strength in 90-Day Challenge

Student Loses 15KG While Increasing Strength in 90-Day Challenge
Emily Wilcock
Writer and expert1 year ago
View Emily Wilcock's profile

YouTuber and Myprotein ambassador Stan Browney is arguably best known for his challenge videos. He takes normal people and puts them through a 90-day fitness programme, usually with impressive results. It's no wonder how he got 2m YouTube subscribers.

Stan’s latest project is 18-year-old student Koos. He’s big, strong and tall. He’s also extremely nice and a little bit clumsy. Koos originally got super-fit during the Covid pandemic but has had ups and downs with his weight since.

Sensing an opportunity to work his magic, Stan hatched a plot to get Koos over to his place and challenged him to take on the 90-day programme. Koos accepted with barely a second’s hesitation.

Two years ago, Koos was inspired to start working out by one of Browney’s transformation videos. He started the 90-day challenge and got way fitter but didn’t keep it up. After a year of little exercise, he went on a seven-month bulk, gaining 23kg (50.7lb).

He began doing only bodyweight exercises but put on so much weight it became too difficult. He feels strong but constantly tired and is no way near as fit as he once was. Now he wants to change.

Koos’s goals

Pre-challenge Koos weighed in at 112.7kg (248.5lb). His goal for the 90-day challenge was to weigh in under 100kg, meaning he’d need to lose around 13kg (28.7lb). Some quick maths revealed that after 30 days Koos would need to lose 5kg (11lb) to be on target, putting him at 108kg (238lb) after 30 days.

Aside from losing weight, Koos had a few other objectives. The first was to get better at bodyweight exercises. His original transformation was based predominantly on this form of exercise, but his weight gain had made it far more difficult to do.

Koos’s other and perhaps most important goal was to get fitter and feel healthier. He no longer wanted to struggle with cardio-based activity and be out of breath in seconds.

The stats (day one)


Shoulders 130cm
Chest 113cm
Waist 96cm
Belly 101cm
Thighs R: 71cm L: 72cm
Upper arms R: 38cm L: 37cm

Strength test

Pull-ups 7 reps
Push-ups 35 reps
Triceps dips 8 reps
Burn 20 calories on the assault bike 8 seconds

The challenge

Koos tracked his journey through self-recorded videos and recorded progress using an Apple watch given to him by Stan, who said he would be able to keep it if he met all his goals at the end of the challenge. He’d also be fuelled throughout by plenty of Myprotein goodies.

For the first nine days, Koos was absolutely killing it, completing all his workouts, eating his protein and burning his target calories. But after 10 days, he was beginning to feel a little run down. He tried to power through but quickly realised training when not feeling 100% isn’t the best idea. Sometimes you just need to listen to your body. After some advice from Stan, he decided to focus on recovering on day 11.

On day 12, feeling rested and ready to go again, he got back in the gym and hit a new PB — three reps of a 180kg deadlift.

Day 15

Although the challenge was going mostly well — aside from a few bad workouts and days of illness — Koos didn’t get the numbers he hoped for by day 15. At the midpoint weigh-in, he was 111.9kg (246.7lb). But he still believed he’d hit the 108kg target by day 30, and his bodyweight strength was definitely improving.

But there were a few more snags to come. On day 22, after suffering an injury and generally feeling exhausted, Koos headed to Stan’s for a deep dive into what was going on. A quick look into the Apple watch stats revealed Koos was not getting proper rest. His sleep quality was only 57% — far from ideal. To fix things, Stan gave him an evening routine for the rest of the challenge in the hope it would help him wind down and get a better night’s sleep.

Day 30 stats

And just like that, it was already the 30-day check in. Koos had his fair share of obstacles over the course of the challenge. Poor sleep, a relentless schedule, injury and illness to name a few.

But the hurdles clearly didn’t stop him. Despite seemingly being unable to lose any weight 15 days in, on the 30th day he’d hit his goal of 108kg.


Day zero Day 30
Shoulders 130cm 128cm
Chest 113cm 112cm
Waist 96cm 91cm
Belly 101cm 95cm
Thighs R: 71cm L: 72cm R: 71cm L: 71cm
Upper arms R: 38cm L: 37cm R: 38cm L: 37cm

Strength test

Day zero Day 30
Pull-ups 7 reps 10 reps
Push-ups 35 reps 45 reps
Triceps dips 8 reps 15 reps
Burn 20 calories on the assault bike 8 seconds 8 seconds

The next 30 days

After the 30-day check-in, Koos was as motivated as ever. Hitting his 30-day goals spurred him on to achieve more. To celebrate the 30-day milestone, Koos joined Stan and co on a week-long holiday. But that wasn't an excuse to let loose. He stuck to his eating plan. Instead of ice cream he had 0% fat Greek yoghurt. One evening he did tuck into pizza but stayed on track with his macros. And the lads got in all their workouts and played plenty of football — so their cardio was through the roof.

But the rest of the challenge wasn’t without its hurdles. Koos was still feeling some of the aftereffects of the back injury he sustained during the first 30 days, and it was hindering his workouts. This meant he had to avoid certain exercises, deadlifts among them.

By day 52, Koos felt compelled to visit the physio to make sure he’d not suffered any serious damage. Fortunately, there was good news: all he had was an irritated spine and recovery wouldn’t be a problem.

Day 60 check in

Good news and not so good news. Koos hit his weight goals but made no further progress in the strength tests. His disappointment was visible.

Strength test results

Day zero Day 30 Day 60
Pull-ups 7 reps 10 reps 10 reps
Push-ups 35 reps 45 reps 39 reps
Triceps dips 8 reps 15 reps -
Burn 20 calories on the assault bike 8 seconds 8 seconds 10 seconds

The next 30 days

The final push. With just 30 days left, Koos wanted to improve his strength test results. He was saying no to all his cravings.

Koos went on a carb cycle for the final eight days of the challenge. For seven days he ate minimal carbs and then loads on the day before the weigh-in. Pasta, bread, tortillas, bananas. In one day he ate 7,000g of carbs — about 4,000 calories. That’s how you go out with a bang.

Day 90 check in

Koos’s initial goal was to lose 12.7kg so he’d weigh less than 100kg. By the time of the weigh-in he wanted to lose at least 15kg in total. And he did it. Over 90 days he managed to lose 15.3kg, weighing in at 97.4kg. Incredible.


Day zero Day 30 Day 90
Shoulders 130cm 128cm 126cm
Chest 113cm 112cm 110cm
Waist 96cm 91cm 81cm
Belly 101cm 95cm 87cm
Thighs R: 71cm L: 72cm R: 71cm L: 71cm R: 69cm L:69cm
Upper arms R: 38cm L: 37cm R: 38cm L: 37cm R: 36cm L:35cm

Strength test results

Day zero Day 30 Day 60 Day 90
Pull-ups 7 reps 10 reps 10 reps 13 reps
Push-ups 35 reps 45 reps 39 reps 53 reps
Triceps dips 8 reps 15 reps - 20 reps
Burn 20 calories on the assault bike 8 seconds 8 seconds 10 seconds 10 seconds

And his strength test results were just as impressive. Across the board, Koos posted improved results and beat his targets.

Take home message

Koos is almost unrecognisable from the beginning of the challenge. He’s met all his targets, losing body weight while getting stronger at the same time. He can now do almost twice as many reps for every bodyweight exercise. It wasn’t easy, and there were many challenges on the way, but he smashed it. Well done, Koos.


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Emily Wilcock
Writer and expert
View Emily Wilcock's profile
Emily is studying Business Management & Marketing at the University of Birmingham and is currently on her intern year. She has a keen interest in both writing and fitness, so is happy she can now combine the two. She likes to spend time with her friends, both in & out of the gym.