A Flexible Nutrition Strategy for Long-Distance Endurance Adventures

Why I’m choosing a hybrid, fat-adapted approach rather than a strict diet --- and why the underlying ideas might be useful for others too.

Disclaimer

This article describes my personal strategy for a long, self-supported endurance expedition. It is not medical advice, not a prescription, and not a claim that this approach is right for everyone. Individual needs vary widely depending on health, training history, genetics, and context. If you have medical conditions or specific concerns, seek personalised professional advice.

When you start planning a long, self-supported endurance journey — whether by kayak, bike, or on foot — nutrition stops being theory and becomes a practical problem. In my case, that journey is Britain by Kayak: a solo, multi-month circumnavigation of mainland Britain, landing on remote beaches and resupplying wherever I can — from tiny village shops to ferry terminals and the occasional supermarket. Some days I’ll eat well; many days I won’t.

After a lot of reflection and real-world thinking, I’ve settled on a hybrid, fat-adapted nutrition strategy. It’s not keto. It’s not high-carb. It’s designed to be robust, flexible, and sustainable.

What follows is my personal framework, shaped by my goals, physiology, and the realities of long, self-supported travel — not a universal prescription.

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The Problem With Extreme Diets

The endurance world is full of strong opinions.

On one side:

“You must eat carbs constantly or you’ll bonk.”

On the other:

“Carbs are unnecessary — fat is all you need.”

Both views have merit, but both can be fragile in the real world. Much of the guidance comes from short races or training blocks — not multi-day or multi-week expeditions where food access is uncertain and conditions vary.

So let’s look at the pros and cons of two common approaches.

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Always High-Carb: Pros and Cons

Pros • Rapid glycogen replenishment • Supports high-intensity efforts • Strong evidence base for racing and intervals • Easy to implement using common foods

Cons • Dependency on frequent refuelling • Energy swings and hunger crashes • Increased logistical pressure • Less efficient for steady, low-intensity movement

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Strict Keto or Very Low-Carb: Pros and Cons

Pros • Increased fat oxidation • Stable energy for long, steady efforts • Reduced reliance on constant feeding • Higher energy density per gram • Reported mental clarity (highly individual)

Cons • High-intensity performance often suffers • Harder to access quick power • Narrower food choices • Difficult to sustain long-term

The obvious question becomes: can I get the benefits of both approaches without their weaknesses?

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What I Mean by “Hybrid, Fat-Adapted”

This approach sits between the extremes.

For me, it means: • Fat as the primary everyday fuel • Carbohydrate as a strategic tool • Protein prioritised for recovery • Preserving the ability to perform when intensity rises • Staying flexible when real life intervenes

Instead of asking “Is this keto?” or “Is this high-carb?”, I ask:

What does my body need today — given what I did yesterday and what I face now?

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Metabolic Flexibility: The Real Goal (For Me)

Metabolic flexibility means switching smoothly between fat and carbohydrate as fuel, depending on the day [6].

In practice: • I can move for hours without constant snacking • Missing a meal isn’t a crisis • I can still produce power when needed • Recovery stays consistent

This matters most for long, steady Zone 1–2 work, where fat can be an effective fuel if the body is adapted to use it well.

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Where Fasting Fits In

I use time-restricted eating or short daily fasts as a tool, not a rule. At home, I often delay breakfast until late morning or lunchtime (typically a 15–18-hour fast). Occasionally, I’ll eat just one meal in a day.

Used sensibly, this may: • Support fat adaptation and metabolic flexibility [6] • Reduce reliance on constant feeding • Make early starts simpler

Fasting should never compromise recovery, warmth, or safety. Hard days need fuel.

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Real-World Awareness

On expedition, food won’t always be ideal.

Sometimes it’s: • A village or seaside café • A ferry-terminal sandwich • A small shop with limited options • Whatever a kind stranger or host offers

That’s fine. A strategy that only works in perfect conditions isn’t much use.

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What This Looks Like in Practice (My Personal Strategy)

This approach is built for real coastal life — Spars, Co-ops, petrol stations — not perfect kitchens.

Fat as a Base Fuel (My Default)

I prioritise calorie-dense, widely available foods: • Olive oil • Nuts and seeds • Tinned oily fish • Nut butters • Cheese and full-fat dairy • Olives • Chorizo

I aim for sufficient calories, typically 4,000–4,500 kcal per day, and sometimes more.

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Protein Is Non-Negotiable (For Me)

Recovery matters, especially as I get older (I’m in my late fifties at the time of writing).

Based on my body mass (~90 kg), I aim for around 120–150 g of protein per day to support recovery, tissue repair, and immune function [8].

Where possible, I also try to distribute protein intake across the day, rather than consuming most of it in one large meal. Repeated moderate protein doses appear to stimulate muscle protein synthesis more effectively than a single large bolus, particularly in older adults and during prolonged training blocks [12–14].

In practice, this suits expedition life anyway — small, regular protein hits from: • Eggs • Tinned fish • Dairy • Jerky or dried/cured meat • Yoghurt • Beans and lentils • Milk-based shakes

I actively try to avoid relying on one large, protein-heavy evening meal.

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Carbohydrates Are Strategic

Carbs aren’t banned — they’re aimed.

Fast carbs are most useful during or immediately after exercise, where they: • Support higher intensity output • Reduce perceived effort and fatigue • Help moderate stress-hormone responses and immune disturbance during prolonged work [3,4]

Outside of exercise, large amounts of fast carbs tend to increase energy swings and hunger — which is counter-productive on long trips.

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Sugar, Confectionery, and Chocolate

Sugar isn’t evil — context matters.

It can be useful: • During long or hard paddles • Late in big days • For morale or emergencies

I don’t ban foods. I use them deliberately.

Dark chocolate (70–85%) earns a special mention: higher fat, less sugar, antioxidant content, and excellent morale value.

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Alcohol, Social Life, and Long Expeditions

Alcohol is part of real life — and on a long, social journey like Britain by Kayak, it’s also part of human connection. I’ve cut down significantly, but I don’t aim for complete abstinence.

Physiologically, alcohol can: • Impair muscle protein synthesis when consumed soon after exercise [15] • Disrupt sleep quality, even if total sleep time feels adequate [16] • Increase dehydration and electrolyte loss • Suppress aspects of immune function when intake is frequent or excessive [17]

These effects are dose- and timing-dependent, and matter most during repeated long days of physical work.

How I Handle Alcohol in Practice • Alcohol is social, not a recovery tool Protein, hydration, warmth, and food come first. • Timing matters Alcohol fits better on short days, rest days, or weather-bound days. • Quantity stays modest One pint socially is very different from several. • Hydration is non-negotiable I consciously rehydrate and replace electrolytes.

Non-Alcoholic Options

Non-alcoholic beers often contain 10–25 g of carbohydrate, which isn’t a problem in context.

Pros • Avoid alcohol-related sleep and recovery disruption • Provide useful carbohydrate post-exercise • Socially inclusive

Cons • Liquid calories with low satiety • Easy to overconsume

I treat them as light carbohydrate drinks with social value, not a free pass — and often as my default.

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Timing of Eating: When Matters More Than Rules

The “30-minute window” post-exercise rule is largely outdated [9,10]. Recovery depends more on: • How hard the day was • How cold and depleted I am • How soon I’ll work again

I prioritise protein first, then carbs when they’re useful. Fat forms the backbone of meals rather than urgent recovery fuel. Refuelling properly within 3–4 hours is more realistic and effective.

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Fibre, Gut Health, and Staying Well

Fibre supports gut health, immune function, blood sugar stability, and appetite regulation [5,7]. On expedition it’s hard to get from small shops, so I plan to use a greens + fibre supplement as a backup — not a replacement for whole foods.

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Immune Function on Long Expeditions

On long, cold, wet trips, illness ends journeys faster than fatigue. • Protein supports immune cell production and tissue repair [8] • Fats, particularly omega-3s, help regulate inflammation [5] • Carbohydrates support glycogen and help moderate exercise-related stress responses [3,4,8]

This is one reason I avoid strict keto long-term.

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My Big Principle: Don’t Underfuel

Fat-adapted does not mean calorie-deprived.

You can fast occasionally and eat fewer carbs — but you still need: • Enough energy • Enough protein • Electrolytes • Immune support

Underfueling quietly erodes performance, recovery, and motivation over time.

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What the Science Says (Selected References)

The following references informed my thinking. This article reflects my personal interpretation and real-world application rather than a clinical or prescriptive approach.

[1] Burke, L. M. et al. (2017). Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. The Journal of Physiology. https://pmc.ncbi.nlm.nih.gov/articles/PMC5407976/

[2] Stellingwerff, T., Morton, J. P., & Burke, L. M. (2019). A Framework for Periodized Nutrition for Athletics. International Journal of Sport Nutrition and Exercise Metabolism. https://journals.humankinetics.com/view/journals/ijsnem/29/2/article-p141.xml

[3] Gunzer, W. et al. (2012). Exercise-Induced Immunodepression in Endurance Athletes and Nutritional Intervention with Carbohydrate, Protein and Fat. Nutrients. https://pmc.ncbi.nlm.nih.gov/articles/PMC3475230/

[4] Christ, T. et al. (2024). Pre- and mid-exercise carbohydrate ingestion attenuates stress hormone responses during endurance exercise. Frontiers in Sports and Active Living. https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2024.1264814/full

[5] Wiertsema, S. P. et al. (2021). The interplay between the gut microbiome and the immune system. https://pmc.ncbi.nlm.nih.gov/articles/PMC8001875/

[6] Smith, R. L. et al. (2018). Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease. Endocrine Reviews. https://academic.oup.com/edrv/article/39/4/489/4982126

[7] Cleveland Clinic (2025). Mucosa-Associated Lymphoid Tissue (MALT). https://my.clevelandclinic.org/health/body/malt

[8] Jeppesen, J. S. et al. (2025). Short-Term Severe Low Energy Availability in Athletes. https://pmc.ncbi.nlm.nih.gov/articles/PMC12180388/

[9] Aragon, A. A. & Schoenfeld, B. J. (2013). Nutrient timing revisited: Is there a post-exercise anabolic window? https://pmc.ncbi.nlm.nih.gov/articles/PMC3577439/

[10] Arent, S. M. et al. (2020). Nutrient Timing: A Garage Door of Opportunity? https://pmc.ncbi.nlm.nih.gov/articles/PMC7400240/

[11] We Do Science — Dr Laurent Bannock et al. Podcast on sports nutrition. https://www.wedoscience.com

[12] Moore, D. R. et al. (2012). Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. The Journals of Gerontology: Series A. https://pubmed.ncbi.nlm.nih.gov/22451437/

[13] Areta, J. L. et al. (2013). Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. The Journal of Physiology. https://pubmed.ncbi.nlm.nih.gov/23459753/

[14] Schoenfeld, B. J. & Aragon, A. A. (2018). How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition. https://pmc.ncbi.nlm.nih.gov/articles/PMC5828430/

[15] Parr, E. B. et al. (2014). Alcohol ingestion impairs maximal post-exercise rates of myofibrillar protein synthesis. PLoS ONE. https://pmc.ncbi.nlm.nih.gov/articles/PMC3943438/

[16] He, S. et al. (2019). Effect of alcohol consumption on sleep quality and insomnia. Sleep Medicine Reviews. https://pubmed.ncbi.nlm.nih.gov/30574049/

[17] Szabo, G. & Saha, B. (2015). Alcohol’s effect on host defense. Alcohol Research: Current Reviews. https://pmc.ncbi.nlm.nih.gov/articles/PMC4590612/

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Closing Thoughts

This isn’t about race-day optimisation. It’s about staying healthy, functional, and motivated over months of uncertainty.

Britain by Kayak is as much a nutritional and logistical challenge as a physical one. I’m not chasing perfection — I’m building something durable.

The real lesson is simple: find an approach that works in your reality, not just on paper.

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