Cyclist Brennan King has completed an astonishing feat of gastric endurance, eating over 11kg of oats in a single week, suffering innumerable “horrific” bathroom breaks while cycling over 1,000km in a challenge that, by his own admission, offered no insight beyond what not to do.
Posting videos detailing his ordeal, and with almost 4 million views on his Instagram original post, King has captivated and disgusted a huge audience over the past seven gut-toiling days.
Posting on the final day, King said he “set oat [sic] to answer a question absolutely nobody was asking”.
Speaking to BikeRadar, King explained his decision to undertake the brutal challenge: “My family buys our oat supply in 25lbs (11kg) bags, and we go through them pretty quickly. So, naturally, I had to wonder how quickly I could make it through one on my own.”
King said he ran the numbers, weighed out the portions, “and it seemed to me like it might (just might) be possible to do it in a week”.
“If I had known how much of a challenge it would be, then I would probably have thought about it a little harder,” he said, admitting he “wouldn’t be able to get the idea out of my head without giving it a go.”
A keen long-distance rider since 2019, King's latest two-month 10,000km adventure took him from his home in Vancouver, Canada, to Banff. He then tackled the legendary Tour Divide from Banff to the Mexico/US border, before riding back to Montreal for the start of the school year.
Other challenges of epic proportions include riding for 24 hours straight on Zwift for his 23rd birthday, when he averaged 268W for 960km (he hopes to crack the 1,000km mark for his 25th birthday).
However, all of these challenges pale in comparison to the gastric mountain he has just summited.
Brennan King’s 10kg week of oats challenge in 5 horrifying numbers
- 1.4kg (20 cups) of oats per day
- 6,000 calories per day
- 59,931 calories total consumed
- 36 hours cycling, 4 hours running, 4 hours hiking and 30 minutes swimming
- Innumerable trips to the toilet
20 cups of oats per day
King says he calculated that a cup of dry oats contains about 300 calories, and to complete this challenge, he had to eat 20 cups each day.
This means 1.4kg of oats per day, which equates to 6,000 calories or 42,000 calories for the week.
For context, Tour de France pros burn in the region of 8,000 calories on the toughest stages.
Mixing things up with a range of recipes pushed his overall calorific intake beyond oats alone. He says: “I was also eating other foods that I was adding to the oat-based meals that I was making. My calculations say that I ate 59,931 calories over the course of the week.”
Though he peppered in a bit of running, hiking and swimming, King rode with a power meter throughout the week, and estimates he burned 52,979 calories.
He adds that “despite the roughly 7,000 calories in excess, I weighed 0.4lbs lighter at the end of the week”.
“Having the bathroom close by was critical”
His weight loss can probably be attributed to the other obvious physical challenges the monotrophic diet presented.
King is unflinching in his description of the trials he faced: “It was horrific. So much diarrhoea.”
Falling behind his required schedule towards the end of the challenge forced King to up his intake on the final day: “I had to up my consumption to 2.4kg of oats on the last day to finish the challenge."
Waking at 4.30am, King said that to “develop the appetite of a horse, I’d need to exercise like a horse”.
Riding laps around a local park, King explains that he “fell into an easy rhythm of stopping every 4 laps to eat my oats and shit my guts out
“Having the bathroom close by was critical to the mission – I had to stop off at a bathroom nearly once per hour during my 12-hour ride.”
Though his resolve wobbled towards the end, King says there was only one thing for it: “Keep on biking, and keep on eating oats.”
So, “in a state of delirium and utter gut discomfort”, King finished the challenge having cycled 335km – and eating more oats than he cares to recount.
King admits the gastric challenge extended beyond the obvious: “It was tricky to come up with tasty recipes because I was trying to use as many oats as possible without too many additives. The trick was to add as little as possible while still making it palatable”
Highlights included a banana oat loaf, classic oats paired with Greek yoghurt, and oat borscht.
However, not every recipe was a hit: “By far my most horrific creation was after a long day when I was tired and just wanted to get some hydration in, so I put a chicken bouillon cube in a bunch of hot water and added oats to that to make a soup. That was despicable.”
On the last day, he was also forced to pair a simple granola with Red Bull: “This was a dark day for oat lovers everywhere.”
What did he learn?
So what did King learn from his monumental challenge? “I can’t say that I gained all that much insight from the challenge – at least not anything valuable about what you should be doing," he admits.
“The on-bike nutrition was really the main hurdle. I think oats and their fibre content are great fuel for off the bike, but trying to ride for 12 hours by eating 2.4kg of them was never a good idea.”
Regardless, he says he “still needed to give it a try”, and that he expected to be in top form having “come off possibly the craziest block of gut training that any cyclist has ever undergone”.
Looking ahead, although his expectations are modest, King is targeting the Canadian National road championships. While he admits he’s come to racing late in life, his dream is to race on a WorldTour team, or on the American gravel circuit.
And what about his taste for porridge, granola and other oaty delights? “I’ll need some time away from oats for a bit," he says. "I still love oats, but this past week has put some strain on our relationship, so I don’t want to rush anything.”
