The Goggins Challenge: Could you run four miles every four hours for two days?

How much punishment can you take in 48 hours? Could you run four miles every four hours for two days? Our reporter loaded up on carbs and set off to find out if she could complete the Goggins challenge

Emily Crowley, journalist, finding her love again with walking and jogging, in Killarney National Park. Photo: Valerie O'Sullivan

WITH job titles including former US Navy SEAL, triathlete, ultra-runner, public speaker, and author, David Goggins has a lot on his CV.

Famed for his mental resilience and motivational words, he boasts 12m followers on Instagram, while the #davidgoggins tag has nearly 480,000 hits on TikTok and 531,000 on Instagram. He also once held a Guinness World Record for completing 4,030 push-ups in 17 hours.

In his 2018 book Can’t Hurt Me, Goggins theorises that humans only tap into 40% of our capabilities, something he coined as the “40% Rule”. It is no surprise that he pioneered the 4x4x48 challenge in 2020 — which stands for four miles every four hours for 48 hours. It is an opportunity for athletes to dip their toes into the world of ultramarathon, and is lauded for its accessibility as there is no registration or “leaderboard”; you go at a time that suits you and at a pace you can manage. 

It totals 48 miles (77.25km), but the incentive is that after every four-mile lap, you get a break until the next four-hour mark. But trust me, that doesn’t make it easy.

With a free weekend in my diary, I set myself the task of attempting the challenge. As a somewhat seasoned runner, I wasn’t going to be fooled — I knew this required more than just lacing up the shoes and heading out the door.

Ideally, I would have contacted dietitian and performance nutritionist Evan Lynch three months before the challenge date to ensure adequate preparation and fueling. But time is not on my side (this is my version of ‘living life on the edge’), so we must look at what we can do. In the run-up to the challenge, Lynch recommends a 24-hour carb load at a rate of 12g of carbohydrates for every kilogram of body weight.

Intra-challenge nutrition is different. “You might take a gel in the middle of each of those [runs] to meet your total carbohydrate requirement. As soon as you finish each four-mile stage, you’d want to get about 70g to 80g of fairly high-GI (glycemic index) carbs. Mix it up: white bagels with jam, Mooju chocolate milk, dried fruits, even a bowl of Coco Pops.”

Hydration is also a huge factor heading into the 4x4x48. Lynch recommends a sweat test — weighing yourself before and after an hour of running to determine water loss — to help calculate hydration requirements.

“Hydration is gonna kick you in the arse after about four or five of those reps, the average sweat rate is 1.2l per hour, and your fluid requirements at a baseline is about 2.7l per day before we factor in exercise,” he explains.

“The only thing that would catch you is you could become complacent in those [breaks] and you could say ‘I have three hours, I’ll have a big meal’. If it’s every four hours, you won’t have time to digest something high in fibre or fat, so you have to be careful in that respect.”

As for recovery fueling? “The day after it’s done, just eat whatever you can — but you might feel a bit ropey”.

Emily Crowley, journalist, in Killarney National Park. Photo: Valerie O'Sullivan

Lower expectations

Physiotherapist Claire O’Sullivan recommends strength training regardless of whether you are setting out to do an ultra challenge.

“If you were a few months out, the focus would be some strength training to get you strong; it would be a focus on lower body,” she says. “You don’t neglect areas of your body and not train the upper body, but it would be more of a focus on the lower body.

“You’d be focusing on quads, glutes, hamstrings, groins, calves, IT bands — preventing the common running injuries.

“The other thing would just be time on the feet,” she adds, referring to how much time you spend training rather than the distance you cover.

O’Sullivan says that running fatigued and at a slower-than-usual pace is another helpful exercise to prepare for the 4x4x48.

“A mistake that people make with this challenge is trying to get the first few runs done fast so that they have more recovery in between [runs], but it’s going to take a lot more out of your body if you [go fast].”

She recommends dynamic stretching (movement-based stretching) before a run and some static stretching (stretches that involve holding a position for 20-30 seconds) post-run.

“Maybe a bit of foam rolling could also be thrown in if you’re running by the pier and going in for a few cold dips.

“The thing with the stop-start nature of this is that after a few runs is that you’ll probably be stiff and you’ll probably be sore heading into the next one, so doing whatever you can to help recover in between and feel a little bit more limber would be good.”

Emily Crowley, journalist, in Killarney National Park. Photo: Valerie O'Sullivan

Running on empty

How did I fare?

I anticipated that my cognitive function and mental capacity would probably diminish as this challenge went on, so I kept a diary in the notes section of my phone to document the experience. It went a little something like this:

Run 1: 5pm: I feel as though I might have overshot the runway with the carb load; I can feel bagels and rice cakes in my oesophagus. After the run, my legs are fresh. I do a few stretches and rest up.

Run 2: 9pm: I can sense the fatigue, but I can move at a light pace. I run past a friend and recruit him to join me for the 1am slot.

Run 3: 1am: Having some company makes the run faster. Running through town as people go home from their night out is weird and we pass by some interesting characters.

Run 4: 5am: Sleeping after the 1am run was hard. A few niggles begin to flare, but I feel smug about seeing the sunrise on this run.

Run 5: 9am: I return home intact, but the lack of sleep is beginning to set in already. Food isn’t digesting fully between the runs.

Run 6: 1pm: Motivation drops, and I have decided to walk some lengths in this one. The niggles are now more intense. Inflammation in the glute now makes this challenge officially a pain in the ass. I phone my brother for access to a massage gun.

Run 7: 5pm: I use the massage gun and it hurts. It gives a brief respite. The will to complete this challenge is depleting faster than I am moving. Neighbours are beginning to look concerned, having seen me jog by for the third or fourth time in 24 hours.

Run 8: 9pm: My body is not cooperating, so I slow completely down to a walk for this one, and my mum joins me. I use it instead to enjoy the fine evening and chat with friends and family I meet along the way; it’s my favourite four-miler. There is no point in acting the hero by continuing and potentially injuring myself. I officially DNF and call time of death to my 4x4x48 challenge after 29 hours.

The thought of heading into another night shift of four-mile runs hurt me mentally and emotionally. I can only imagine that for anyone who has managed to complete the challenge, it would have been one of the more demanding stages of the event. And yes, it can be disappointing and disheartening to “fail” a challenge like this. Still, it can also be encouraging: I can prepare and train to be a more efficient athlete and return to reach a new goal of simply completing it.

• Readers interested in attempting the 4x4x48 challenge should seek advice from the appropriate professionals

Expert tips

Lynch and O'Sullivan offer advice for athletes participating in a challenge such as the 4x4x48 or a similar one:

VO2 max: Your VO2 max, in simple terms, is the amount of oxygen your body uses while you exercise. Two weeks before the first run, Lynch advises: “Start taking beetroot juice shots, two of them a day between now and whenever you’re finished. It will improve your VO2 max and make you a bit more efficient as a runner.”

Oxidative stress: Taking a high-dose vitamin C and zinc supplement will help prevent oxidative stress, which would, in turn, lead to a lactate build-up, causing cramps. Another supplement also gets a shoutout from Lynch, beta alanine. “That’s a lactic acid buffer, 5g a day. It will probably come into effect when you get absolutely snookered, it will slow down the rate at which lactic acid accumulates.”

Cramps: Cramping is a frequent and common issue for most athletes, no matter what the sport. If you suffer from cramps, Lynch says that pickle juice is your friend. “If you feel muscle cramp coming on, having a mouthful of pickle juice actually stops it. It short circuits your nervous system by interacting with something called the ‘TRP channel’ in your oesophagus, it will stop a cramp almost in its tracks.”

Blisters: O’Sullivan recommends taking preventative steps. “Have stuff prepared—plenty of fresh socks, maybe some different shoes as well.”

Grab a pal: Doing runs over and over will eventually become monotonous. ““This is going to be a mental challenge as much as anything, as you do a few runs, as you’re tired, if you have a few friends who run, try and schedule them in for different lengths of it for a bit of company,” O’Sullivan says.