I experience nausea during every ultra marathon I run. It typically kicks in around mile thirty-five and remains with me well after the race has finished, sometimes for up to twelve hours afterwards.
Nausea is surprisingly common among ultra runners. In fact, Rod Bien writes in Training for the Uphill Athlete that he has thrown up in every single one of his eighteen 100 mile races, sometimes as many as ten or twenty times per race... apparently he has become so used to it that he can throw up without breaking stride!
After two disappointing races in 2019, I really tried to get on top of my nausea issue in 2020: I ran four, forty mile efforts in a row, trying out different fuelling strategies with mixed results each time. In late 2021, I was diagnosed with Diverticular disease, which might explain some of my nausea woes but after yet another disappointing day out recently, I resolved to find a solution... or learn how to throw up without breaking stride!
There's a lot of information out there... this is my attempt to compile, and to some degree, annotate a list of resources that I've found helpful.
tl;dr
- Nausea is very common
- Train like you're racing: put as much effort into training your gut as you do everything else
Podcasts
Koopcast
GI Issues in Ultrarunning with Kyle Smith
Interview with Kyle Smith, the lead author of the paper entitled Gastrointestinal pathophysiology during endurance exercise: endocrine, microbiome, and nutritional influences.
- 00:16:03 Main causes of GI distress: mechanical damage to gut lining (jostling), blood flow restriction (redirection of blood to skin and muscles), psychological (anxiety) and nutritional factors (leading up to the race)
- 00:29:18 Prevention of GI distress: train the gut with fluid and carbohydrate intake during training, increase tolerance over time, customise nutrition in the days leading up to a race
- 00:38:34 Low FODMAP diet: avoiding high fibre foods, lactose and dairy twenty-four hours before a race may help
- 00:43:03 On race day, when GI distress strikes, slow the pace and calorie intake, the place of medication as an intervention including proton-pump inhibitors
GI Issues in Ultrarunning. Problems and Solutions with Jamie Pugh PhD
- 00:13:40 Consider diet and train the gut from eight to ten weeks out, also avoid fatty and high fibre foods for forty-eight to twenty-four hours before a race
- 00:17:35 The low FODMAP diet
- 00:29:15 Training the gut
- 00:45:02 Probiotics
Ultramarathon Nutrition for Training and Racing with Nick Tiller
A superb three hour, ten minute deep dive! This podcast is split into two halves: the first half deals with nutritional requirements for training and the second half covers race day nutrition (including a lot of information about GI distress and how to combat it). Nick Tiller (MRes, Ph.D.) is an ultra runner and a senior researcher in exercise physiology at Harbor-UCLA... he certainly knows his stuff and he is the author of Nutritional Considerations for Single-stage Ultra-marathon Training and Racing, the paper which this conversation is based around.
Training
- 00:14:25 Strategies for determining calorific requirements
- 00:30:40 Macronutrient distribution of carbohydrate and fat
- 01:02:40 Macronutrient distribution of protein, 20~30 grams every three to four hours
- 01:14:55 Hydration
Racing
- 01:20:09 Energy expenditure during racing, carbohydrates and calories
- 01:24:50 Limitations of the gut… up to 90% of ultra runners experience upper GI distress, how many calories can you absorb? Sixty to ninety grams of carbohydrates per hour (for marathon distance), glucose and fructose but for ultra distances, ninety grams per hour is going to cause GI distress
- 01:42:40 Aim for 240 to 260 calories per hour (sixty grams of carbohydrates) and train for four to six months, even twelve months out
- 01:46:20 Fat intake during an ultra
- 01:57:55 Protein, getting in some protein during the race, ten to twenty grams every two to three hours
- 02:12:50 Hydration
- 02:44:10 GI distress
- 02:56:26 Supplements
The Ultrarunner's Gut with Patrick Wilson PhD RD
Billy Yang Podcast
Jason Koop
A listener call in (beginning at 01:01:30) about mild nausea onset at mile thirty of ultra marathons... advice from Jason Koop:
- Train like you're racing: take in more calories on long training runs than you anticipate doing during a race
- Keep experimenting with different fuelling strategies during training runs
- Heat and altitude will increase the chances of experiencing GI distress
- Even elite runners experience GI distress
- Slow down and cool off to allow blood to redirect towards the stomach to aid digestion
Trail Runner Nation
EP 583: TRAINING PRINCIPLES – Nutrition
EP 579: Keep Your Gut and Brain Happy
EP 517 Eat to Train
EP 471: Running 100 Miles Without Food?
Ep 422 – Sunny Blende Returns! 5 Pre-Race Nutrition Mistakes to Avoid
The Science of Nutrition
How to Avoid Stomach Distress
Starts at 00:20:00
Tea and Trails
Episode 3 - Elsey Davis
Brew with the coaches section beginning at 00:22:43 - discussion on carbohydrates and calories
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