A Fueling Plan Built Specifically for the Boston Marathon

Every aid station on the course, what it serves, and the exact minute you reach it based on your goal time. Then a fueling plan built on this exact course, so every gel is timed to avoid the hills and where there is water to wash it down so you never hit the wall in the last 6 miles.

Build my Boston plan Start with the course ↓
Boston Marathon presented by Bank of America
Monday 19 April 2027 · 26.2 miles
Water + Gatorade Endurance 24 Gel depot miles 11.8, 17 and 21.5
Map of the Boston Marathon course with the 24 aid tables marked
© OpenStreetMap contributors
Elevation profile drag along the profile to scrub
26.2 miles ▲ 457 ft gain ▼ 897 ft loss 0 ft high -442 ft low
0 mi 5 10 15 20 26.2 mi 0 ft 0 mi 10 20 26.2 mi 0 ft

Aid tables from the B.A.A.'s own race course pocket guide, checked 12 Sep 2026. Boston publishes miles; kilometres are converted. Map data © OpenStreetMap contributors.

Why the course changes the plan

Why you need to adapt your fueling plan to the specifics of the course

Most fueling plans are generic: take a gel every 30 minutes, wash it down with water and drink your carb beverage in between.

But, what if your planned time to take a gel comes right in the middle of a hill? What if there’s no aid station close by to grab water from?

Often, where each gel goes on the course matters as much as how many you take

It’s these small, often ignored parts of executing a fueling plan that trip runners up and have them hitting the wall or slowing down because of an upset stomach, despite having a well-rehearsed fueling plan heading into the race.

4

things go wrong when you don’t account for the course in your fueling plan

1A planned gel with no water

You plan a gel at 60 minutes, but the next water station isn’t for another 15. That means you either have to wait, take it without water and have it sit, or take it with your carb beverage and take in too much sugar for your stomach to process.

2You miss a table

Boston had 28,487 runners on the road in 2025. Tables that busy are easy to misjudge and not get the fuel you need. Without a plan for the next one you either double up later and pay for it, or run the rest of the race short.

3Your plan calls for a gel in the middle of a hill

As intensity increases, your stomach’s ability to process carbohydrates slows down. Couple that with breathing harder up a hill and you’ve got the perfect storm for a gel that can’t be digested fast enough.

4Miscalculating the fluid on the course

The distance between aid stations, the concentration of the carbohydrate drink, and how much you’re actually able to swallow all change how much glycogen you’re actually replacing every hour. Your plan calls for 60 g per hour, but if you only hit 40 g you’ll run out of glycogen before you finish.

So your fueling plan needs to start with one question, and everything after it follows.

Option 1

I am going to use what is on the course

Water at 24 tables, Gatorade at all of them, gels at miles 11.8, 17 and 21.5.

What that adds up to, and what you still carry.

Fuel off the course ↓
Option 2

I am going to carry all of my own fuel

Your products, your timing, nothing riding on a cup you might miss.

What the course still decides for you.

Fuel from your own kit ↓
Option 1

If you are going to use what the course hands you

Boston is a good course to do this on. Water and Gatorade Endurance come at all 24 tables. Below is where you’ll find each station.

Boston Marathon course strip Elevation relative to the start across 26.2 miles, the 24 aid tables marked by mile with what is at each, and the 12 feeds of the reference plan as numbered dots. 0 ft -442 ft 2.1 3.1 4.4 5.2 6 7.1 8 8.9 10.1 11.2 11.8 13.3 14.1 15 16 17 18.1 19.1 20.1 21.1 21.5 23.1 24.1 25.1 mi 1 2 3 4 5 6 7 8 9 10 11 12
Water + Gatorade Endurance Gel depot Feed in the 3:45 plan, on a table Feed with no table, water carried

Elevation is stretched to emphasis location. The numbered dots are your recommended fueling options for your 3:45 goal.

Source: the official Boston Marathon, checked 12 Sep 2026

1What is on the course

What is provided at Boston, and where

Water is provided at all 24 tables, from mile 2.1 to mile 25.1.

Gatorade Endurance at every table, so there is carbohydrate in the cup each time you drink. Gels at miles 11.8, 17 and 21.5, Maurten Gel 100 / Gel 100 CAF 100.

The course climbs 457 ft in total, and 2 climbs are steeper than 3%: the first of the Newton hills at mile 17.5 and Heartbreak Hill from mile 20.25 to its crest at mile 20.8. CarbRate keeps your feeds off those climbs and on the water tables either side.

The Boston course, table by table
Water stations
24

every table, mile 2.1 to mile 25.1

Gatorade Endurance
24

every table from mile 2.1 to mile 25.1

Gel 100
3

miles 11.8, 17 and 21.5, water at each

2Your goal time

Every table, and the minute you reach it

Put your goal time in and when you arrive at every aid station on the course recalculates. This is the list to put in your pocket, and the one CarbRate builds your feeds on.

Arrival times assume even pace, which is a rough guide on a course with this much climbing. At 3:45 you reach the first gel station at 1:41.
Build my Boston plan
All 24 tables at 3:45
mikmTableWhat’s at the tableYou arrive
2.13.4AshlandwaterGatorade Endurance0:18
3.15.0Hydration stationwaterGatorade Endurance0:27
4.47.1Hydration stationwaterGatorade Endurance0:38
5.28.4FraminghamwaterGatorade Endurance0:45
69.7Hydration stationwaterGatorade Endurance0:52
7.111.4Hydration stationwaterGatorade Endurance1:01
812.9NatickwaterGatorade Endurance1:09
8.914.3Hydration stationwaterGatorade Endurance1:16
10.116.3Hydration stationwaterGatorade Endurance1:27
11.218.0Hydration stationwaterGatorade Endurance1:36
11.819.0Wellesley — Maurten depotwaterGatorade EnduranceGel 1001:41
13.321.4Hydration stationwaterGatorade Endurance1:54
14.122.7Hydration stationwaterGatorade Endurance2:01
1524.2Hydration stationwaterGatorade Endurance2:09
1625.8NewtonwaterGatorade Endurance2:17
1727.4Newton — Maurten depotwaterGatorade EnduranceGel 1002:26
18.129.1Hydration stationwaterGatorade Endurance2:35
19.130.7Hydration stationwaterGatorade Endurance2:44
20.132.3Hydration stationwaterGatorade Endurance2:52
21.134.0Hydration stationwaterGatorade Endurance3:01
21.534.6Boston College — Maurten depotwaterGatorade EnduranceGel 1003:05
23.137.2BrooklinewaterGatorade Endurance3:18
24.138.8Hydration stationwaterGatorade Endurance3:27
25.140.4BostonwaterGatorade Endurance3:35
3The course drink

How much glycogen does the Gatorade on the course provide

Gatorade Endurance is 6 g of carbohydrate per 100 mL. A typical cup contains about 200 mL.

But, you likely won’t actually drink that much. Volunteers typically fill cups about half way to prevent water from splashing and you’ll lose a good amount as you run with the cup and what spills as you drink.

On average, you can expect a net intake of about 60 to 90 mL per cup

This is the part most runners don’t account for in their fueling plan, so CarbRate builds it directly in your plan.

We’ll tell you exactly how many cups at each aid station to drink based on how much glycogen you need and how much you’ll be able to supplement with gels.

What the drink is worth per hour
Glycogen left
200 → 60–90 mL

A cup holds about 200 mL. Half-filled, spilled and sipped on the run, 60 to 90 mL of it actually goes down.

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you run out here Planned full cups Real 60–90 mL a cup full empty start finish
Glycogen left across the race, a plan built on full cups against what a cup actually delivers. Illustrative, not your plan.
4What you carry

How many gels you still carry

After you’ve calculated how much of the course drink you’ll likely take at each aid station, you’ll need to fill in your glycogen needs with gels along the course.

A typical gel contains about 25 g of carbohydrate, so use the chart here to calculate how many you’ll need.

If you’ve practiced fueling in training, you can target 75 to 90 g per hour. If you haven’t trained your stomach, err closer to 60 g per hour.

Here’s more on how to practice your fueling schedule to maximize your gut tolerance.

25 g gels to carry, after the course
Finish60 g/h75 g/h90 g/h
3:45 your goal
3:000to12to34to5
3:302to24to46to6
4:002to35to57to8
4:303to46to78to9
5:003to56to89to11
5The products

The 2 products Boston hands you

The gel is Maurten, handed out plain or with 100 mg of caffeine at all three depots, and the drink is Gatorade Endurance, which carries real sodium. Practise with both before race day so mile 11.8 is not the first time your stomach meets them.

If Maurten does not sit well with you, the closest matches are Precision Fuel PF 30 Gel, SiS Beta Fuel Gel and Maurten Gel 160. Pick one before race week and train on it.

On the Boston course
Sodium
20 mg
Caffeine
0 mg (CAF 100: 100 mg)
Glucose : fructose
about 1.25 : 1
Science score100/100
Full write-up, who it suits →
Sodium
300 mg / 12 oz
Caffeine
0 mg
Glucose : fructose
sucrose and dextrose

Get a Fueling Plan Built for Boston

CarbRate builds you a personalized race fueling plan from your own sweat rate, how your stomach handles gels, and then it coaches you through every feed, live, while you run.

It also customizes every gel and every drink placement to align with the actual elevation profile and aid station on your course.

Build my Boston plan
Option 2

If you are going to carry all of your own fuel

Even carrying your own fuel, the Boston course influences 4 things about your fueling plan: the timing of your gels, fluid intake, the hills, and caffeine.

1Timing

Set your feed times to Boston’s tables, unless you carry water

The common advice is to take your gels every 30 to 45 minutes, but that might not coincide with when you hit an aid station.

If you’re not carrying your own water with you, you’ll need those aid stations to wash down your gel.

For a 3:45 finisher, Boston’s tables arrive 18, 27, 38, 45 and 52 minutes in, then every 3 to 14 minutes.

So, you need to factor this into your fueling plan.

Enter your goal time in the input box below and we’ll show you when each aid station will arrive for your given pace.

If you want a fueling plan with all of these built in, CarbRate does this for you. Start building your plan here.

Feed times assume even pace, which is a rough guide on a course with this much climbing. Everything below recalculates from 3:45.
Your watch against Boston’s tables
Gel alarms with water
6 of 11 alarms

For a 3:45 finisher, 6 of 11 twenty-minute alarms land within 2 minutes of a table. Highlighted tables take a gel in a 75 g an hour plan; the first goes down before mile 2.1 from a bottle you carry.

Gel alarm every 20 min Boston tables, 3:45 pace 2.1 5.2 8 10.1 11.8 14.1 16 19.1 21.1 23.1 25.1 start 1:00 2:00 3:00 finish
alarm within 2 min of wateralarm with no watertable taking a geltable not taking a gel
How many 25 g gels that is, carrying everything
Finish60 g/h75 g/h90 g/h
3:45 your goal91214
3:008911
3:3091113
4:00101215
4:30111417
5:00121518
2Water

A gel needs more water than a cup holds

Research has shown that the optimal carbohydrate concentration is 6 to 8 percent carbohydrate to water.

That means you’ll want about 100 mL (3.5 oz) of water for every 8 grams of carbohydrate you take in. A typical gel contains 25 g of carbohydrate, so you’ll want to aim for about 300 mL (10 oz) of water with each gel.

A good estimate is that each cup of water will provide you 100 mL (3.5 oz) of water. That’s because volunteers typically fill cups about half way to prevent water from splashing and you’ll lose a good amount as you run with the cup and what spills as you drink.

So, if you’re not carrying your own water, have your gel open and prepared to take at the start of the aid station so you can take it early with a cup of water and still have time to grab another cup or two.

What a gel needs and what a cup delivers
One 25 g gel needs
300 mL
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cupsempties fast, no sloshing8%concentration300 mL+2 cupsstill too thick to empty13%concentration200 mL+1 cupsits in your stomach25%concentration100 mL
3Hills

The hills change where your fuel goes, not how much

The carbohydrate you need per hour is the same on a hilly course as on a flat one. What changes is which aid stations you can take it at, when you reach them, and where your caffeine goes.

Keep your gels off the climbs

Your stomach slows down digestion as your effort increases running uphill. This happens because blood moves from your gut to your legs, so a gel taken on a hard climb sits there instead of being absorbed.

So, keep your gels off any climb steeper than about 3 percent, and take them on the flat before it or the flat after it.

Boston has 2 climbs like that: the first of the Newton hills at mile 17.5 and Heartbreak Hill from mile 20.25 to its crest at mile 20.8.

Long, steep descents are no better. Below about 7 percent your quads are doing the braking and everything in your stomach is bouncing, so wait for the grade to ease before you take anything.

If you want a fueling plan with your gel and drink timing customized to the course, CarbRate does this for you. Start building your plan here.

Where the climbs are
Climbs steeper than 3%
2 on the course

Heartbreak Hill from mile 20.25 to its crest at mile 20.8 is the climb that decides your race, so your caffeine goes in about an hour before it.

Boston Marathon course strip Elevation relative to the start across 26.2 miles, the 24 aid tables marked by mile with what is at each, and the 12 feeds of the reference plan as numbered dots. 0 ft -442 ft 2.1 3.1 4.4 5.2 6 7.1 8 8.9 10.1 11.2 11.8 13.3 14.1 15 16 17 18.1 19.1 20.1 21.1 21.5 23.1 24.1 25.1 mi
climb steeper than 3%, no gel heretable with water, a gel lands here
4Caffeine

Time your caffeine so it helps you when you need it the most

If you plan to use caffeine, it’s best to time it so the benefits kick in on the climb that decides your race rather than at the start.

Caffeine peaks in your blood about an hour after you swallow it, then it slowly falls.

With a goal finish time of 3:45 that would place your caffeine at mile 13.3 (21 km), about an hour before Heartbreak Hill at mile 20.2.

This should provide you with peak benefits from the caffeine right when you need it the most.

When the caffeine is working
Caffeine table, before the climb
mile 13.3
1 hour 54 minutes into a 3:45

Blood caffeine peaks about an hour after the dose, so a mile 13.3 gel peaks near mile 20 for a 3:45 finisher, on Heartbreak Hill.

the climb starts Heartbreak Hill, from mile 20.25 to its crest at mile 20.8 dose at the start mile 13.3 table · 1:54 peak ≈ mile 20 0 mi 5 10 15 20 26.2 mi peaknone
dose at the mile 13.3 tabledose at the startwhere the decisive climb startscurve shape illustrative, timings from your goal time

Get a Fueling Plan Built for Boston

CarbRate builds you a personalized race fueling plan from your own sweat rate, how your stomach handles gels, and then it coaches you through every feed, live, while you run.

It also customizes every gel and every drink placement to align with the actual elevation profile and aid station on your course.

Build my Boston plan
Built for your exact course

What a finished Boston plan looks like

This is a real CarbRate plan rather than an example we wrote out: a 68 kg runner, 3:45 goal, trained stomach, drinking the Gatorade and taking the course gel, 14 °C at the start. Adjusted finish 3:48. Target 81 g an hour, 307 g in total, as 12 feeds of 25 g.

12 of the 12 feeds land on a real Boston aid table, so there is water in your hand for every one of them.

#ClockmiWhereWhat
10:172.0Ashland · mile 2.1One 25 g gel, your own
20:273.2Hydration station · mile 3.1One 25 g gel, your own
30:455.3Framingham · mile 5.2One 25 g gel, your own
41:087.9Natick · mile 8One 25 g gel, your own
51:2610.0Hydration station · mile 10.1One 25 g gel, your own
61:4311.9Wellesley — Maurten depot · mile 11.8Gel 100 / Gel 100 CAF 100 from the depot
72:0314.2Hydration station · mile 14.1One 25 g gel, your own
82:2016.1Newton · mile 16One 25 g gel, your own
92:4519.0Hydration station · mile 19.1One 25 g gel, your own
103:0321.0Hydration station · mile 21.1One 25 g gel, your own
113:2023.0Brookline · mile 23.1One 25 g gel, your own
123:3825.1Boston · mile 25.1One 25 g gel, your own

The first feed comes before the first table on purpose: CarbRate starts you early, with the water you carry from the start line. Say you are carrying your own instead and it rebuilds this same timeline with your products and more feeds, on the same tables. On race day the app calls each feed by voice as you reach it.

This is one runner. Yours will look different.

CarbRate builds yours from your weight, your sweat rate, your goal time, the gels you already train with, and the race-day forecast. Answer a few quick questions and it is built, with the Boston course already loaded.

Build my Boston plan
What CarbRate says about Boston

What CarbRate flags on a Boston plan

These are the warnings CarbRate attaches to a Boston plan, word for word, for the 3:45 runner above.

Plan to carry

Boston hands out Gel 100 / Gel 100 CAF 100 at 3 points. You need about 12 feeds, so that covers roughly 24% of your carbohydrate. Take them if you want them, and carry the other 9.

In your favour

Boston has Gatorade Endurance Formula at 6 g per 100 ml, which is strong. Drinking 500 ml an hour covers about 30 g/h of your 81 g/h target, and your plan has already taken that off your gels.

Quiet on purpose

The first table is at mile 2.1. CarbRate allows 45 minutes for the opening stretch instead of the usual 27, because you start hydrated and fed. So Boston’s first 2.1 miles never trigger a warning.

Sodium: on the course

Gatorade Endurance carries about 840 mg of sodium per litre as mixed, above the 600 mg per litre target. The race does not publish its own dilution, so that figure is the maker’s standard mix.

Drink it at the tables and your sodium is covered. Carry your own water instead and CarbRate works out how much you need from your sweat rate and the forecast, and puts it on the same schedule as your gels.

Shows inside 10 days
219 days to go

From 9 April the start-line forecast appears here, with what it changes in your plan. On a warm day: more fluid and more sodium.

The short answers

Boston Marathon fueling at a glance

Every fact on this page in one block, for the runner who wants the answer and nothing else.

Race
Boston Marathon presented by Bank of America, 19 April 2027
Distance
42.195 km / 26.2 mi
Aid tables on the course
24
First table
mile 2.1 (km 3.4)
Spacing after the first table
every 0.4 to 1.6 miles
Water
at every table
Sports drink
Gatorade Endurance Formula, at every table
Drink strength
6 g carbohydrate per 100 ml
Gel handout
Maurten Gel 100 / Gel 100 CAF 100, mile 11.8 (km 19), mile 17 (km 27.4) and mile 21.5 (km 34.6), 3 points
Food on course
none published
Personal refreshment
not accepted for the mass field
Published sodium
840 mg per litre in the course drink, maker’s mix
Total climb
457 ft, steepest grade 4.6%
Typical carbohydrate target
60 to 90 g an hour
Gels to carry, 3:45 at 75 g/h
4 to 4 using the course drink, 12 carrying everything

Boston fueling questions, answered

Is there Gatorade on the Boston Marathon course?

Yes. Gatorade Endurance Formula is at every table, mile 2.1 to mile 25.1, alongside water. Maurten Gel 100 / Gel 100 CAF 100 is handed out at miles 11.8, 17 and 21.5.

Where are the gel stations at the Boston Marathon?

Miles 11.8, 17 and 21.5, which is km 19, km 27.4 and km 34.6. There is water at each of them. Plan to carry the rest of your own.

How many gels do I need for the Boston Marathon?

It depends on your carbohydrate target and how much of the course drink you take. At 75 g an hour a 3:45 finish needs about 280 g. Drinking one cup of Gatorade at every other table covers roughly 110 g of that, which leaves about 7 gels of 25 g, 3 of them handed out on the course, so carry 4. Drinking half a litre of Gatorade an hour, carry 4. The grid above works this out for any finish time.

Is the Boston Marathon hilly?

Yes. Our course profile shows 457 ft of climbing across 26.2 miles with 2 climbs steeper than 3%: the first of the Newton hills at mile 17.5 and Heartbreak Hill from mile 20.25 to its crest at mile 20.8. CarbRate keeps your gels off those climbs and on the tables either side of them, and arrival times assume even pace only as a rough guide.

Does Boston have electrolytes or sodium on the course?

Yes. Gatorade Endurance carries about 840 mg of sodium per litre as the maker mixes it, which is above the 600 mg per litre target. The race does not publish its own dilution. If you carry your own water instead, bring your own sodium plan.

Is there food on the Boston Marathon course?

Boston publishes none. The tables carry water and Gatorade Endurance and nothing else.

How far apart are the water stations at Boston?

The first table is at mile 2.1. After that they come every 0.4 to 1.6 miles. The longest gap after the start is mile 21.5 to mile 23.1, about 2.6 km, which is 15 minutes at 4:00 pace and 18 minutes at 5:00 pace.

When will I reach the gel station at mile 11.8?

At even pace: 1:35 into a 3:30 race, 1:41 into a 3:45, 1:48 into a 4:00, and 2:15 into a 5:00. Enter your own goal time in the station table above to see every table.

Where are the aid stations at the Boston Marathon?

There are 24, at miles 2.1, 3.1, 4.4, 5.2, 6, 7.1, 8, 8.9, 10.1, 11.2, 11.8, 13.3, 14.1, 15, 16, 17, 18.1, 19.1, 20.1, 21.1, 21.5, 23.1, 24.1 and 25.1. All 24 have water. Every one of them also has Gatorade Endurance Formula.

Can I carry all of my own fuel at the Boston Marathon?

Yes. Boston does not take personal bottles from the mass field, so everything you carry starts on you at the gun, with water at every table to top a flask from. Carrying everything at 75 g an hour is 12 gels of 25 g for a 3:45 finish, or 9 if you take the course gels.

How much carbohydrate should I take during the Boston Marathon?

60 to 90 grams an hour, set by your body size and by how much your stomach has practised absorbing. Start at the rate you have already trained at rather than the rate you want: 90 g an hour is a target to build toward over a training cycle before you race on it.

Do I need to carry water at the Boston Marathon?

Only for the opening 2.1 miles. The first table is at mile 2.1, about 18 minutes into a 3:45 race, and after that tables come every 0.4 to 1.6 miles. If your first feed comes before mile 2.1, carry the fluid for it from the start line.

What should I eat before the Boston Marathon?

1 to 4 g of carbohydrate per kg of body weight in the 1 to 4 hours before the start, from food you have already eaten before long runs. A 68 kg runner eating 3 hours before the start needs roughly 130 to 200 g of carbohydrate. Boston sets off in waves, so work backwards from your own wave time rather than from the elite start.

Your Boston plan

Build your Boston plan with the course already loaded

The tables, the Gatorade and the course profile above are already in. Add your weight, goal time, sweat rate and the gels you like, and CarbRate builds your feed-by-feed plan for Boston, then calls each feed by voice on race day.

Build my Boston plan

The plan is free. Live race-day guidance and the practice schedule are in the app, $9.95 a month or a one-time $49.95 Race Pass that expires after your race.

Fueling guides for the other courses

Boston, 19 Apr 2027
Free plan, course loadedBuild my Boston plan