Ocean rowing nutrition: how to fuel 5,000+ calories a day at sea

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. Updated November 2026.

Quick answer: Rowers on the World's Toughest Row Atlantic burn more than 5,000 calories a day, according to the race organisers, and the organisers' food rules have required at least 60 calories per kg of body weight per day, which is 6,000 a day for a 100kg rower. Plan for 40 to 50% of that to come from compact, no-cook snacks eaten one-handed on shift, because the average rower still loses about 8kg on the crossing.

About this guide

Ocean rowing is one of the most calorie-hungry sports there is, done in one of the hardest places to eat.

Rowers on Atlantic crossings burn more than 5,000 calories a day, and heavier rowers in rough weather considerably more, while rowing two hours on, two hours off for anything from a month to more than two months. Every gram of food must be carried aboard a boat that's typically 24 feet long and 5 feet wide. There is no refrigeration, no fresh food, and no resupply. The organisers' rules have required rowers to carry food for at least 60 calories per kg of body weight per day for a prescribed number of days; check the current rulebook for your year.

Despite this, the race organisers put the average weight loss at about 8kg per rower, because getting enough calories in is almost as hard as the rowing itself. Fatigue, seasickness, limited preparation options, food fatigue, and the sheer volume of eating required all work against adequate fuelling.

This guide focuses specifically on practical approaches to maximising calorie intake during an ocean row, with particular focus on the role of compact, calorie-dense foods.

It covers:

• the calorie maths: how much you actually need and why most rowers fall short
• why food selection for ocean rowing is fundamentally a weight-to-calorie problem
• what food has to cope with in an open-ocean environment
• practical strategies for closing the calorie gap during a crossing
• how compact, calorie-dense options can supplement freeze-dried rations

It also explains how ocean rowers have used Phoenix Bars, which I make, as part of their on-board nutrition: up to 557 calories in a compact, 120g bar.

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. Phoenix Bars have been carried on Atlantic crossings.

Last updated: November 2026

Key points: Ocean rowers burn more than 5,000 calories a day for a month or more. The average rower loses about 8kg during an Atlantic crossing despite trying to eat enough. Every gram of food competes for space and weight on a small boat. Calorie density (calories per gram) is the first thing to check when choosing food. Phoenix Bars carry up to 557 calories in only 120g and have a shelf life of up to two years.

Contents

1. The calorie problem on an ocean row
2. How long it takes to row the Atlantic
3. Why most ocean rowers lose weight
4. The weight-to-calorie equation
5. What makes food work at sea
6. Common food challenges during an ocean crossing
7. Practical strategies to maximise calorie intake
8. Why calorie density is the defining factor
9. The role of snacking between rations
10. How Phoenix Bars fit into ocean rowing nutrition
11. Practical suggestions for an Atlantic crossing
12. Frequently asked questions
13. Related guides

The calorie problem on an ocean row

Start with the numbers.

A rower in the World's Toughest Row Atlantic race (formerly the Talisker Whisky Atlantic Challenge and still the best-known ocean rowing race, about 3,000 miles from San Sebastián de La Gomera in the Canary Islands to Nelson's Dockyard in Antigua, starting each December) will typically row for 12–16 hours per day in a continuous two-on, two-off shift pattern. The organisers say rowers burn more than 5,000 calories a day; the exact figure depends on body weight, rowing intensity, and conditions.

For a 100kg male rower in a pairs crew, the Atlantic Campaigns minimum requirement in rules crews have published is 60 kcal per kg of bodyweight per day, which is 6,000 calories a day, for a prescribed minimum of 65 days. That equates to 390,000 calories that must be carried aboard the boat before departure.

The table applies the same rule to other body weights. Food weight assumes an average of about 450 calories per 100g across freeze-dried meals and snacks, so it is approximate.

To put this in perspective: 6,000 calories is roughly two and a half times the 2,500 calories the NHS suggests for an adult man. It is like eating six full meals a day, every day for two months, in a cramped boat in the middle of the Atlantic.

Every rower knows the number before they leave. Getting that much food down, day after day, is the hard part.

How long does it take to row across the Atlantic?

On the World's Toughest Row, the fastest crews of four have finished in under 30 days, while many pairs and solo rowers take 50 days or more. The race leaves La Gomera in early December, so plan your food for the slow end of your likely range, not the fast one: bad weather, injury or a broken rudder can add weeks.

Why most ocean rowers lose weight

Despite carrying enough food and knowing the maths, the average ocean rower loses about 8kg during an Atlantic crossing, according to the race organisers, and some lose a great deal more.

The reasons stack up.

Seasickness. Particularly in the first 1–2 weeks, seasickness can make eating impossible. Some rowers survive the opening days almost entirely on liquids and whatever they can keep down.

Exhaustion. After hours of continuous rowing, the energy to prepare and eat food can feel unavailable. The two-hour rest window is needed for sleep, navigation, and boat maintenance, so eating competes with rest.

Food fatigue. Eating the same rotation of freeze-dried meals for 40–70 days creates deep monotony. Even foods that were enjoyable on day one become psychologically difficult by day 30. Many rowers report that the sight of certain meals is enough to put them off eating.

Mastication fatigue. When exhausted, even the physical act of chewing becomes effortful. Hard, chewy, or dry foods become increasingly difficult to eat as the crossing progresses.

Preparation time. Freeze-dried meals require boiling water and rehydration time. In rough seas, handling a stove and waiting 10–15 minutes for food to rehydrate can feel like an impossible luxury.

Heat and humidity. Tropical Atlantic conditions (up to 40°C) can cause some foods to deteriorate, melt, or become unpalatable. Chocolate, many energy bars, and some snacks become a melted mess.

Limited space. On a 24-foot boat shared with one or more crew members, food storage competes with safety equipment, sleeping space, water-making equipment, and everything else needed to survive.

The cumulative result is that most rowers eat less than they need, most days, for the entire crossing. The weight loss is the visible evidence of a persistent calorie gap.

The weight-to-calorie equation

Ocean rowing nutrition is fundamentally a weight-to-calorie optimisation problem.

Every kilogram of food loaded onto the boat adds weight that must be propelled across 3,000 miles of ocean. Heavier boats are slower. In a race context, every unnecessary gram costs time. In any crossing context, total boat weight affects speed, manoeuvrability, and safety.

So the number to compare foods by is calories per gram. A food that delivers 300 kcal per 100g is twice as efficient as one that delivers 150 kcal per 100g. Over 65 days of eating, this difference translates to tens of kilograms of food weight, or hundreds of thousands of extra calories in the same weight budget.

The table shows what a 6,000-calorie day weighs at different calorie densities, using typical UK values. Figures are approximate.

The most common food types on ocean rows reflect this:

Freeze-dried meals are the staple because removing water dramatically reduces weight. A typical freeze-dried meal delivers 500 to 1,000 calories per pouch, at roughly 4 to 5 calories per gram before water is added. They require a stove and fresh water to prepare.

Snack bars, nuts, and dried fruit fill the calorie gaps between meals. These are eaten throughout the day during rowing shifts. Their calorie density varies hugely: a standard cereal bar might deliver 100–150 kcal, while high-calorie bars can deliver 400 to 550 kcal or more each.

Protein shakes and calorie drinks deliver liquid calories that need no chewing, which rowers value more as fatigue builds across the crossing.

"Wet rations" (foods that need no water to prepare) are reserved for emergencies, storms, and days when cooking is impossible. Rules that crews have published required 13 of the 65 days of food to be in this format.

The implication for food selection is clear: the highest calorie-to-gram ratio wins. Every snack, bar, and meal should be evaluated on this basis.

What makes food work at sea

Salt water, heat and constant motion are hard on food. What works in training or on land does not necessarily work on a mid-Atlantic rowing boat.

Food for an ocean crossing needs to be:

• Calorie-dense, so every gram carried earns its place.
• Stable in heat, because temperatures on an Atlantic crossing can exceed 40°C and foods that melt or spoil become a liability.
• Long-lasting without a fridge, staying safe and edible for 2 to 3 months from provisioning to the last day.
• Well sealed in waterproof, crush-resistant packaging, because salt water, humidity and constant movement destroy anything that isn't.
• Open-and-eat, since anything that needs cooking time or complex preparation becomes a barrier.
• Soft enough to eat when exhausted, as chewing gets harder the further into the crossing you are.
• Not sickly sweet, because overly sweet snacks become intolerable after weeks of eating them.
• Varied, with several flavours in each food type to keep you willing to eat.

Common food challenges during an ocean crossing

Rowers report the same few food problems again and again.

Standard energy bars fail. Many popular energy and protein bars are either too dry and chewy to eat when exhausted, too sweet for sustained daily use, too low in calories to justify their weight, or melt into an inedible mess in tropical heat. Rowers often end up abandoning bars they had planned to rely on. Our ranking of the best energy bars for expeditions compares the alternatives on calories per gram first.

Freeze-dried meal fatigue. While freeze-dried meals are calorically efficient, eating them twice a day for 50+ days causes deep psychological aversion. The textures, smells, and flavours become triggers rather than appetisers.

The snack gap. The calories between main meals (the thousands of kcal that need to come from snacking during rowing shifts) are where most rowers fall short. Snacks need to be eaten one-handed while rowing, in any weather, without preparation. Most rowers underestimate how many snack calories they need and under-provision.

Night eating. During night rowing shifts, the combination of darkness, exhaustion, and cold makes eating feel impossible. Yet the calorie burn continues. Many rowers skip eating during night shifts entirely, creating a significant calorie deficit.

Wet ration days. During storms or equipment failure, the inability to heat water means freeze-dried meals are unusable. Ready-to-eat options become the only food source, and most crews don't carry enough of them.

Practical strategies to maximise calorie intake

Provision more snack calories than you think you need. Most crews under-provision snacks. The calories between freeze-dried meals (eaten during rowing shifts, at night and between rest periods) should make up 40–50% of the daily total: on a 6,000-calorie day, that is 2,400 to 3,000 calories of snacks.

Choose the highest calorie-to-gram snacks available. Compare snack options by kcal per 100g and select the most calorie-dense options that you can tolerate eating repeatedly. A bar with up to 557 calories in only 120g carries nearly twice the calories per gram of a 60g bar with 150 calories.

Carry a variety of flavours and textures. Food fatigue cuts how much rowers eat on a long crossing. Carrying 6+ flavour variations of any snack food you plan to eat daily gives you options when one flavour becomes intolerable.

Front-load calories early in the day. Many rowers report that appetite is strongest in the first few hours after waking. A calorie-dense breakfast (ideally porridge or a similar warm meal) before fatigue builds puts a solid block of calories in early.

Eat on a schedule, not on appetite. Hunger signals become unreliable at sea due to seasickness, exhaustion, and the constant low-level stress of open-ocean rowing. Eat by the clock, something every 2–3 hours, whether or not you feel hungry.

Have one-handed, open-and-eat options for rowing shifts. Anything that requires two hands, a spoon, or preparation time will not get eaten during a rowing shift. Break bars into pieces before your shift and keep them in a pocket or open container within reach.

Plan specifically for night shifts. Pre-portion calorie-dense snacks into night-shift bags before going to sleep. Having food ready to grab in the dark, with no preparation, is the only way most rowers eat anything between midnight and dawn.

Test everything in training. Never take food on a crossing that you haven't eaten repeatedly during long training rows. What tastes good at rest may be intolerable after 10 hours of rowing in 35°C heat.

Why calorie density is the defining factor

In ocean rowing nutrition, calorie density (calories per gram of weight) is the number to judge every food by.

The entire food supply must be carried on a small boat. Every gram of food displaces something else or adds drag. At the same time, the rower needs 5,000–6,000+ calories per day for 40–70 days. The food that delivers the most calories in the least weight is the food that makes the crossing possible.

For context: a standard cereal bar delivers approximately 150 kcal at 40g, roughly 375 kcal per 100g. Trail mix delivers approximately 450–500 kcal per 100g. A freeze-dried meal delivers approximately 400–500 kcal per 100g (before water). A Phoenix Bar delivers up to about 464 kcal per 100g (up to 557 kcal in only 120g), and needs no water, no preparation and no cooking.

Over a 65-day crossing at 6,000 kcal per day, the difference between a snack delivering 375 kcal per 100g and one delivering 464 kcal per 100g translates to kilograms of saved weight, or thousands of additional calories in the same weight budget.

The role of snacking between rations

For most ocean rowers, freeze-dried meals provide the calorie base: typically two or three meals a day, or about 1,500 to 3,000 calories. The rest, often 3,000 calories or more on a 6,000-calorie day, must come from snacking throughout the day.

This snacking component is where most rowers fall short and where the calorie gap accumulates. The ideal snack for ocean rowing:

• Can be eaten one-handed while rowing
• Requires no preparation or utensils
• Is calorie-dense enough to deliver meaningful calories in a few bites
• Won't melt, spoil, or deteriorate in tropical conditions
• Has a soft texture that can be managed when exhausted
• Isn't sickly sweet (to prevent flavour fatigue over weeks)
• Comes in multiple flavour options

Packing a mix of nuts, dried fruit, nut butters, chocolate (in cooler conditions), biltong, and calorie-dense bars, with variety within each, gives the best chance of maintaining snack intake across the full crossing.

How Phoenix Bars fit into ocean rowing nutrition

I make Phoenix Bars, so read this section with that in mind. They started as my idea for a ration bar that packs maximum calories into minimum weight, which is the same brief an ocean row sets.

In heat, a Marathon des Sables runner found they kept their shape even in desert temperatures, and a rider on the Race Around Rwanda said they did not melt into a mess.

Each bar carries up to 557 calories, up to 66g of carbohydrate and up to 19g of protein in a compact, 120g bar. In practice, on a rowing boat they:

Are easy to eat when exhausted. Bars can be broken into pieces and eaten one-handed during a shift, even 12 hours into a day of rowing.

Offer flavour variety. Phoenix Bars come in six flavours: Vanilla, Cherry Bakewell, Chocolate, Salted Caramel, Ginger, and Apple & Cinnamon. Over a 50–70 day crossing, this variety helps combat the food fatigue that degrades eating in the later weeks.

Mix with water into porridge. Adding water to a Phoenix Bar creates a calorie-dense porridge, an easier option when solid food feels difficult, particularly during seasickness or in the early days of a crossing. For instructions, see how people use Phoenix Bars.

Keep for up to two years. The shelf life of up to two years (12 months for Cherry Bakewell) means bars can be provisioned months before departure.

Phoenix Bars have been carried on Atlantic crossings by ocean rowers who chose them for the calorie-to-weight ratio and the practical qualities described above.

Practical suggestions for an Atlantic crossing

Provisioning: Carry 2–3 Phoenix Bars per day as snack rations alongside your freeze-dried meals. Over 65 days, that's 130–195 bars (approximately 15.6–23.4kg) delivering up to 72,000–108,000 additional calories. Bars come in the 18-bar Essential Bundle (£94.50) and the 36-bar Complete Bundle (£189); four Complete Bundles (144 bars, £756) cover two bars a day for 65 days with 14 to spare.

Daily pattern: Eat one bar as a pre-dawn porridge breakfast (add water from the desalinator). Break a second bar into pieces for grazing during day rowing shifts. Keep a third bar portioned for night rowing shifts.

Shift eating: Before each rowing shift, break half a bar into 4–5 pieces and put them in a pocket or open container within arm's reach. Eat one piece every 20–30 minutes while rowing. This adds up to about 275 calories per shift without interrupting rowing.

Seasickness days: During the first week when seasickness is likely, the porridge format may be more tolerable than solid food. Mix a bar with water to a thin consistency and sip it gradually. Any calories retained are better than none.

Storm days (wet ration days): Phoenix Bars require no water, no cooking, and no preparation. They work as a reliable wet ration, ready to eat straight from the packet in any conditions.

Flavour rotation: If carrying bars for 65 days, rotate through all six flavours on a weekly cycle. This prevents any single flavour from becoming aversive.

Storage: Store bars in a waterproof dry bag in an accessible location. They do not need refrigeration, and a shelf life of up to two years (12 months for Cherry Bakewell) comfortably covers provisioning time plus a 65-day crossing.

Frequently asked questions

How many calories do ocean rowers need per day?

The World's Toughest Row organisers say rowers burn more than 5,000 calories a day, and heavier rowers in rough conditions burn considerably more. The race has required rowers to carry a minimum of 60 kcal per kg of bodyweight per day; check the current rulebook for your year. For a 100kg rower over 65 days, that's 6,000 calories per day, or 390,000 calories in total.

How much carbohydrate and protein do ocean rowers need?

The American College of Sports Medicine's 2016 position statement suggests 8 to 12g of carbohydrate per kg of body weight a day for very heavy training loads of four to five hours or more, and 1.2 to 2.0g of protein per kg. For a 100kg rower that is 800 to 1,200g of carbohydrate and 120 to 200g of protein a day, which is why freeze-dried meals, oats, rice, bars and sweets make up most of a rowing boat's food store.

What do ocean rowers eat in a day?

A typical day is a porridge or granola breakfast, two freeze-dried meals made with water from the desalinator, and a steady stream of snacks on every shift: nuts, dried fruit, biltong, sweets, bars and electrolyte drinks. Many crews pack each day's snacks into a numbered bag so nobody has to think about food when they are exhausted.

Why do ocean rowers lose so much weight?

The race organisers put the average loss at about 8kg per rower, despite carrying adequate food. This is caused by seasickness (particularly in the first week), fatigue that reduces eating motivation, food fatigue from months of repetitive meals, difficulty eating during night shifts, and the sheer volume of calories required exceeding what most people can physically consume.

Will Phoenix Bars melt on an ocean rowing boat?

Customers who have used them in serious heat say they hold up. Matt Hill took them on the Marathon des Sables and wrote that they didn't melt in the heat, and Paul Blinstone said they kept their shape even in desert temperatures. Plain chocolate and many chocolate-coated bars often become unusable in sustained heat.

How many Phoenix Bars should I take on an Atlantic crossing?

A practical recommendation is 2–3 bars per day, depending on how much of your total calorie target you plan to cover with bars versus freeze-dried meals and other snacks. Over 65 days at 2 bars per day, that's 130 bars. At 3 bars per day, 195 bars. Contact me directly to discuss bulk provisioning for your crossing.

Can I make Phoenix Bars into porridge on a rowing boat?

Yes. Adding water from your desalination unit to a Phoenix Bar creates a calorie-dense porridge. This is particularly useful during periods of seasickness when solid food is difficult to tolerate, or as a quick breakfast that doesn't require a full freeze-dried meal preparation.

Do Phoenix Bars count as wet rations?

Phoenix Bars need no water and no preparation: they can be eaten straight from the packet. They meet the practical definition of a wet ration, though you should confirm with your specific race organisation how they classify provisioned food.

Related guides

You may also find these guides helpful:

• Ultra-Endurance & Expedition Nutrition Guide: broader guide to nutrition for extreme endurance events
• Marathon Des Sables Nutrition: another extreme endurance context with similar calorie-density demands
• Calorie-Dense Foods: What They Are and When They Help: a full explanation of calorie density
• How To Use Phoenix Bars: practical guidance including the porridge method

Buy Phoenix Bars

James Frost

Founder, Flaming Phoenix

jfrost@flaming-phoenix.co.uk

07990 519422

Sources: World's Toughest Row organisers (Atlantic Campaigns), published race information and race rules; NHS, Understanding calories; American College of Sports Medicine, Academy of Nutrition and Dietetics and Dietitians of Canada, joint position statement on nutrition and athletic performance (2016); Typical UK food values per 100g, for the calorie density table; Phoenix Bars nutrition values from our own pack labels.