Nutrition and hydration for women at altitude

The biggest nutritional challenge for women at altitude is maintaining adequate energy supply by eating and drinking enough, especially in the face of conditions that make this normally simple task more difficult.

"If you asked me if I could climb for 18 hours above 6000m on 3 jelly babies, a piece of marzipan, and 200ml of water, I’d have said no. That’s exactly what I did on my summit day on Ama Dablam; it wasn’t the plan, nor would I recommend it!"

Eating enough:

You'll often find that your appetite is suppressed at altitude, which makes it harder to eat enough. Since you also need more calories in the cold just to stay warm, some weight loss is inevitable, but you should be trying to minimise it.

Exercise requires fuel, and you can’t expect to perform your best without putting enough gas in the tank. Experience will tell you which foods you crave (and which you can’t tolerate) at altitude, and as your taste buds are affected, it’s important to take a variety of food to ensure there is always something you can stand to eat. 

It’s more important to get enough calories in than to worry too much about the composition of the food. That being said, carbohydrates are the key to energy supply during exercise, so make sure you consume enough before, during, and after big days. Sufficient protein is also vital for women in the immediate pre/post activity phases to help prevent muscle break down and injuries. This becomes more critical the longer the duration of the trip, but it can help improve recovery and muscle repair after any intense effort.

Drinking enough:

Maintaining hydration is also a significant challenge, as altitude increases urine production and water vapor loss through breathing. Women have more issues to manage when it comes to taking toilet breaks, which can often lead to limiting fluid intake (consciously or otherwise).

Dehydration at altitude can contribute to life-threatening conditions like AMS, HAPE and HACE. It also significantly impacts your physical performance: you could undo a lot of the effort you put in to training just by not drinking enough on the mountain. It’s worth finding strategies to help manage any anxiety that might prevent you drinking enough. 

The reality:

It's one thing knowing all this, but it’s another matter entirely putting it into practice. Needing to melt snow for water, having the energy needed to prepare meals, and the difficulty of eating and drinking on the move are all issues that must be overcome if you’re going to fuel yourself effectively.

Here's a real-life example of how these factors can play out on the mountain side:

"Starting from Camp 2 on Ama Dablam meant we had a long summit day with 800m+ of ascent over 6000m. At about 9.30pm, we started melting snow to make hot drinks and eat a boil in the bag meal and left the tent at 11.30pm. 

During the climb I had gloves/mitts on the entire time, so could only access the snacks I had in my jacket pocket (and even that was hard to do, wrappers were a nightmare). The only time I drank was when we stopped briefly (every 6 hours or so), and my water bottle was semi-frozen despite being insulated, so I hardly felt like drinking – it was cold enough!

Needless to say, I didn’t stop to pee the entire time. When we got back to the tent at 5.30pm I finally had a pee but was too tired to bother with the faff of melting more snow for another hot drink and meal. I drank the rest of my water bottle and ate a snack, then collapsed into a deep sleep.

The next morning we melted enough snow for tea and I forced down some porridge, before packing up and heading down to Camp 1 and then basecamp. The hardest part of the entire experience was the section between Camp 2 and Camp 1; I felt like I had completely hit the wall and could barely put one foot in front of the other. One bowl of hot steaming noodles later and I felt vaguely human again and made it safely back to basecamp. I had completely underestimated how hard it would be to consume enough food and drink on the mountain, something I will remember for next time."

Stategies to help:

It's worth spending some time working out how to make eating and drinking as easy as possible, both for the duration of the expedition and on the climb itself. Pick meals that are easy to digest, and quick to prepare and cook. Making sure you have snacks and drinks on hand that are easy to access, with gloves on (remove wrappers in advance), and that don’t freeze is vital. Aim to eat and drink something at every opportunity, even if you don’t feel like it.

Try to pre-hydrate as much as possible, and start off with hot liquid in your bottle or flask to delay how quickly it cools. If you need a caffeine kick to get you going in the morning, bear in mind it has a diuretic effect (it stimulates urine production) so make sure you consume enough other liquid to counteract this. It's also worth knowing that hypertonic sports drinks with high carbohydrate content (i.e. 5-8% sugar) are actually not that effective at hydration. You're better off drinking isotonic solutions which help replace the electrolytes you lose during exercise and are absorbed more quickly.

Women travelling to altitude should also be aware that the iron levels in their blood will affect their ability to acclimatise, and since low iron (anaemia) is common among menstruating women, it is worth considering iron supplements in the months leading up to a trip. It’s not possible to boost iron levels significantly in the short term, so taking iron supplements during an expedition is unlikely to have much effect.

Depending on where you are travelling, if fresh food is likely to be difficult to come by then vitamin supplements may be helpful for longer duration trips. Similarly if protein availability is limited, then taking some protein powder that you can use to supplement your diet on longer trips or after intense efforts can aid recovery.

Getting your nutrition and hydration right will pay dividends in terms of your performance and chance of success, and most importantly how much you enjoy the experience. If you’d like to learn more, the UIAA (International Climbing and Mountaineering Federation) has recently reviewed existing research on nutrition in women at altitude. The scientific paper can be found here.