Marathon runner running with a hydration pack

We had another great marathon training question pop up in the forums in the Coach Parry Training Club this week.

Chandre is about to run her first marathon and was wondering if you can wear a hydration pack when running a marathon?

Yes, you can absolutely wear a hydration pack when running a marathon. That is on the condition you have been using the hydration pack while training (Marathon Rule #7 – Nothing new on race day). The better question would probably be should you run a marathon with a hydration pack? And is a hydration or running belt better than a hydration pack?

Having a pack with your own hydration and nutrition during a marathon can definitely be beneficial but there are drawbacks to running with a pack.

The Pros and Cons Of Running a Marathon With a Hydration Pack

There are a few benefits to running with a hydration pack. First and foremost, it allows you to stay hydrated. As a runner, you are able to run your best if you are adequately hydrated.

You are also able to run your target marathon using what you’re used to using during training if you run with a hydration pack.

This is a massive advantage when you are running a marathon in a foreign country or if the race has nutrition or hydration products you haven’t used before. (See Marathon Rule #7 above 😉 )

Most hydration vests also have a front pocket or two that provides additional storage that will allow you to carry anything else that you may need when running a marathon.

It’s always helpful to have a storage pocket that has an ‘emergency stash’ of things you may need at some stage during a marathon. It’s ideal for things that the on-course aid stations won’t have. Just make sure the pack design is such that you have easy access to those pockets when the pack is on your back.

A small tub of lube, an energy bar or gel, and your cell phone. Running a marathon with a hydration pack makes carrying those extra goodies super simple.

On the flip side of that coin,  there are also disadvantages to running a marathon with a hydration pack.

Firstly, the extra weight you need to carry is going to slow you down.

According to a study that was done in 1978 at the University of Georgia, for every extra 5 pounds of weight, you slow down by 1.4 seconds per mile.

In the metric system that equates to just under 1 second (0,86) per kilometer for every extra 2,3 kilograms.

But What Does That Actually Mean?

If your hydration pack weighs 5lbs or 2,3kgs then you’ll lose about 36 seconds over the marathon distance. Double the weight of the pack and you double the amount of time you’ll lose.

The second disadvantage of running a marathon with a hydration pack is that you may be putting unnecessary strain on your body.

Another scientific study done at Curtin University in Perth found that running with extra weight puts a strain on the body’s ability to absorb the shock of running.

This is caused by increasing the rolling in of the hips as well as the angle between the top of the foot and the shin. Over time this could have a negative effect on your knees and ankles.

4 Tips For Running a Marathon With a Hydration Pack

If you’re going to run a marathon with a hydration pack then these 4 tips will go a long way to making sure you have a great run:

  1. Make sure your hydration pack fits correctly
  2. Lube up
  3. Travel light
  4. Remove excess air to stop your hydration pack from sloshing

The first thing you need to do if you’re planning on running a marathon with a hydration pack is to make sure your pack fits correctly.

When buying a hydration pack it is most definitely not a case of one size fits all. You want to try a pack on before purchasing.

Adjust the straps, move your arms as you would when you run, and if possible take it for a short run. Even better would be to add some weight to it.

Hydration packs often perform differently whether they are fully loaded or empty.

Also, make sure the pack is tight fighting. You don’t want any unnecessary bouncing or movement that could cause chafing or irritation as you progress deeper into your marathon.

The breathability of your hydration pack also goes a long way to making sure you’re comfortable running a marathon in it. If your hydration pack is causing you to overheat during a marathon, then you’re not going to want to run with it.

If In Doubt, Lube It Up

One way to ruin a run is to experience chafe! Wearing a hydration pack when running a marathon does increase your chance of chafing.

Making sure your pack fits correctly so that there is no excessive movement of your hydration pack on your back goes a long way to ensuring that you don’t chafe. Even if your pack is a comfortable fit, there is a chance that some rubbing may occur under your arms or around your neck.

So using some form of lube can prevent this irritation from happening during your marathon.

As discussed earlier, extra weight in your hydration pack during a marathon can slow you down so it is vital to make sure you travel light. 

Checking what will be on the course before a marathon will help you to know what you should and shouldn’t carry in your pack. The lighter you can keep your hydration pack the better for you in the long run.

How To Stop Your Hydration Pack From Making a Sloshing Sound

The fourth tip for running a marathon with a hydration pack is something simple but will avoid tons of irritation for both you and those runners around you during your marathon.

In marathons, you’ll often you will hear a sloshing coming from a hydration pack. If you are anything like me, things like that can really get under your skin in the second half of the marathon.

In order to prevent your hydration pack from sloshing, all you need to do when filling it up is make sure you squeeze out any excess air. You almost want your hydration bladder to look like it’s been vacuum-packed after it’s been filled up.

Having no air in their bladder will prevent your pack from making a sloshing sound when running a marathon.

What About Wearing a Hydration Belt For a Marathon?

Yes, you can most definitely wear a hydration belt when running a marathon. Again, the consideration should be whether or not you should be wearing a hydration belt.

As discussed earlier in this article the question should rather be should you wear a hydration belt during a marathon.

Before choosing whether a hydration belt or pack would be better to use when running a marathon, various factors need to be taken into account.

Things like:

  • What nutrition and liquids will be on-course
  • what are your personal nutrition & hydration requirements and
  • whether or not you will have someone to support you who could possibly hand you nutrition and hydration

All these factors should come into the equation and dictate whether or not you should wear a hydration belt when running a marathon.

Failing to prepare an adequate hydration strategy before race day can lead to unwanted consequences… This is how to hydrate correctly.

Should I Carry My Own Water For a Marathon?

Most marathons around the world are very well supported from a hydration and nutrition point of view.

Unless you’re doing trail runs or running a marathon in a very remote part of the world then you probably don’t need to carry your own water. Unless a marathon needs you to be fully self-supported, then there is no particular reason to have to carry your own water.

In the last few years, there has been a big movement toward reducing the waste that is produced by marathons and half-marathons. One of the big areas of contention is drinking cups and plastic water sachets that are discarded after a big half marathon or marathon.

There is obviously a massive environmental impact having tons of non-biodegradable waste simply dumped after a marathon. Carrying your own water will go a long way to reducing your waste footprint in a marathon or half marathon.

One of these initiatives that are gaining some momentum was started by Modern Athlete under the hashtag run clean.

Hydration Belt vs Hydration Pack – Which Is Better For a Marathon?

Over the marathon distance, I think the choice between a hydration belt and a hydration pack is purely a personal one.

If you were running longer than a marathon I would definitely recommend a hydration pack over a hydration belt.

Hydration beltss or fuel belts are great to use if you want to carry some extra supplements like gels or salt tablets and perhaps one or two small bottles.

If you are planning on carrying a lot more liquid then a hydration pack would definitely be the way to go when running a marathon.


With a passion for high performance sport – Lindsey Parry is one of South Africa’s most widely recognised coaches. Having led a team to the London, Rio and Tokyo Olympic Games as well as the Commonwealth Games in Edinburgh, the Gold Coast & Birmingham, and coached both triathletes and runners onto podiums of some of the world’s most illustrious races, Lindsey has a unique ability to understand what it takes to succeed at any level and thrives on coaching, motivating and inspiring others to do the same – whether it’s on the track, on stage or behind a mic.

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