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Winter Sports Enhancement using Cytomax and GU

I have never been a fan of sports recovery drinks or powders like Gatorade and don’t normally use them for 3 season backpacking because I feel that frequent all day snacking with unprocessed foods provides me with adequate calories and sodium.

Cytomax and Gu
Cytomax and Gu

However, I just finished a book called Extreme Alpinism: Climbing Light, Fast, and High by Mark Twight and James Mason, and recommended to me by Chris White who writes the blog Hiking and Climbing  in Japan. This is an incredible book and I’ll dedicate a separate post to reviewing in more detail. In it, Twight and Mason provide some very technical insights into how to fuel your body for maximum performance during cold weather climbing. Solid food is not in the equation.

Granted; mountain climbers are fanatics, but I thought I’d give Twight and Mason’s nutritional recommendations a go. During the day of a climb, they recommend that you eat:

  • GU Carbohydrate gel: one package every half hour, taken with a few ounces of plain water.
  • Fluid replacement drink: half a liter per hour.
  • As a last resort, when you hit the wall: halva, meat sticks or an energy bar.

Here’s their reasoning: It is impossible to stay hydrated while actually climbing, so pre-hydration, hydration after hard effort, and hydration at the end of the day are essential. When you become slightly dehydrated, your stomach and entire system become highly acidic, your muscles hold onto metabolic waste, and your glycogen reserves are used up. While you must hydrate, you should avoid acidic food and drink and ingest foods to buffer the acidity in your system.

Acidic foods, fatty foods, foods with fiber, or a lot of protein all impede gastric emptying, or in less technical terms, the time it takes to absorb food into your bloodstream.  In fact, your body cannot absorb more than 400 calories an hour during exercise without inhibiting gastric emptying. This can be achieved optimally by consuming 100 calorie packs of GU carbohydrate gel and a buffering fluid replacement drink, like Cytomax. Eating any kind of solid food will compromise your performance by causing blood to leave your muscles in favor of the digestive system.

GU is an energy gel that supplies 25 grams of carbohydrate in the form of glucose polymers and fructose. When combined with a few mouthfuls of water, it forms a solution that is 4-8% carbohydrates and optimal for gastric emptying. The same holds for the sports drink called Cytomax, whose main ingredients are maltodextrin, a source of glucose polymers, and lactate with the acid removed, which improves gastric emptying. Gatorade and other commercial sports drinks contain simple glucose and sucrose which interfere with gastric emptying, but are often preferred because they are sweeter.

So that’s the science. Now, let’s review two experiments I ran this weekend, that test Twight and Mason’s nutritional enhancement recommendations.

Experiment One

On Saturday, I bought a tub of Cytomax at REI. I mixed a quart bottle of it and took it to my health club for a stationary bike workout. Before my workout I drank 16 oz, and after that I drank another 4 oz, every 15 minutes.

My stationary bike workouts are punishing. I typically warm up for 30 minutes at a moderately difficult level, and then do an hour of intervals, alternating every 5 minutes between very high resistance and lower reistance for another hour. I normally just consume water during my workouts and I am beat tired at the end of them.

However, last night, after consuming a quart of Cytomax drink I was amazingly alert and felt like I could have cycled for another full hour at the end workout. That feeling persisted throughout the evening and I had no soreness or post workout fatigue on Sunday morning.

Experiment Two

On Sunday morning, I went for a 5.6 mile snowshoe on fresh powder carrying a full, 25 lb. pack. This was my first time carrying a full pack on this route and I completed my loop in just 3 hours, beating my previous best time by 15 minutes.

When I woke up this morning, I had two cups of coffee and a large bowl of granola. This is my normal breakfast before a snowshoeing workout. I then pre-hydrated with 32 oz. of water followed by a packet of GU, before driving 10 minutes to the trail head. I always pre-hydrate in winter.

After I put on my snowshoes and started my hike, I drank 4 oz. of Cytomax every 15 minutes (1L = 270 calories) and consumed a packet of GU every 30 minutes. Therefore in the course of the next 3 hours, I consumed 705 calories, while burning about 1800 calories, at a pace of approximately 600 calories/hour.

I am usually pretty tired after going snowshoeing on this trail and quickly journey to the land of Nod. Not tonight. I’m alert and feel normal, even revved up.


I’m amazed by the degree to which my performance has been enhanced this weekend and by the lack of post-workout fatigue I have experienced. I am going to continue to use Cytomax and GU to prolong my stationary bike workouts and on major winter expeditions.

Disclosure: The author owns this product and purchased it using their own funds.


  1. Very glad to hear that both the gel and Twight are working for you!

    Something else to consider are amino acid supplements – leucine, isoleucine and valine (also mentioned in Twight's book). I add them to my homemade Gu gel and aim for around 300mg per hour intake. Alternatively you can mix it into your water bottle. I do know some people who mix an entire 3600mg sachet in a cup of water and drink it in a sitting – that caused problems for me, so I suggest trialing it at home first.

    As an aside, the homemade gel powered my wife (a non-climber) all the way from the first stage of Mt Fuji and back down again. That's 19,000 feet total elevation change, in 22 hours. Testament, if such is needed, to the benefits of carb gel!

  2. That's a heck of a testimonial, but I bet LOVE helped. I'll check out those amino acids. Thx.

  3. I read the book and also use GU for my alpine pursuits and long bike rides. However, when I consulted a renowned alpinist about using GU, he warned me to take it with moderation. He said that after using GU for many years at a high dose, both Mark Twight and Steve House developed some health conditions. Twight and House are sponsored by GU, so they won't say anything negative about it.

    This guy climbed with House and Twight for many years (a photo or two in Twight's book). Because he is also a well-known sponsored athlete, I will not disclose his name here.

  4. I guess if you eat the equivalent of 15 snickers a bar a day it will turn you into a mutant too. Everything in moderation.

  5. I use a product called Perpetuem by Hammer Nutrition for long winter days. I mix up two 1 liter bottles at the start of the day and leave my 3rd bottle as plain water. Consuming a half liter per hour gives me 27 grams of carbs, 7 grams of protein, 270 calories and 16 ounces of water all at once. I supplement with gels as/if needed. I also keep a serving in powder form just in case I need/want to mix up my 3rd bottle with Perpetuem. It's a great product that really works wonders for me and might for you as well.

  6. Milton – welcome to the page where all the really crazy winter people hang out! Personally, I take 1 cytomax and 2 waters for the day, but bring along extra baggies of the stuff for dinner because it really helps on carbohydrate recovery at night. Still it's good to know about another similar mix with twice the calories. I'll have to give it a try. Thx for the tip.

  7. I was stunned to find so many sports drinks offered for sale. They get rave reviews everywhere, and lots of fantastic claims. Kinda scary. Salt and sugar at $10/pound is a little much to swallow.

    ~ How about Helen's Rocket Fuel. You make up plain granola with powered buttermilk. Get it a little soupy and let it set while you stuff the tent. After a while spoon out the granola, and discard it under the shelter floor. Stir in a package of lime Jello. Strain the remaining chunks with your teeth. Then strap on your pack and fly to the next trail head.


    ~ I ordered a barrel of this stuff—fruit punch flavor—and it was horrible. Lovie spit it out. Two of my athletic schoolboy helpers gagged on it. Tasted like laundry detergent to me. Couldn't imagine anybody would voluntarily drink a pint of it.

    ~ So I called the company and was connected to a very enthusiastic customer service rep. He told me something must be wrong and promised to send replacements. Today the package arrived, and this product tasted good. The citrus flavor was even better. Here's the goodie box. I feel more muscular already.

    ~ After deeply contemplating the finely printed ingredient list, it looks like I got a batch that was short on citric acid. There was an instinctive urge to fix this myself, but I'll just return it. Lots more productive things to do. Another shipment arrived at post office. Tomorrow we taste test Vitalyte and Cytomax citrus flavors head to head.

  9. Here's a spreadsheet comparing the nutritional factors of a few common drink mixes.

    Some highlights: Vitalyte is the easiest and fastest drink to enter the bloodstream, and the serious choice for sustained rehydration.

    ~ Cytomax touts a mixture of carbohydrates, with longer digestion rates, intended to provide time released energy. It is a sports energy drink for those who cannot drink continuously and gullible athletes desperate to believe the company's fantastic claims of performance enhancement, lower oxygen consumption, prevention of muscle fatigue, blah, blah, blah. We all have our mind games, and they make a business out of it.

    ~ Gatorade is nutritionally close to Cytomax, but based on cheaper and better tasting sucrose.

    ~ The tea mix is specified extra strong because it is intended to be chilled and diluted with ice. For trail use or hot tea, it should be cut back by a third.

    ~ All of these produces are designed to be consumed at 5% concentrations. At that level, and even 50% stronger, none impose any digestive restrictions or the dreaded "gastric emptying."

    ~ In the distant past, I favored tea mixes because they were good hot and cold. Today we know more and can do better. I've integrated all of these products into my trail diet, with 8 flavors to keep me amused for a month.

    ~ Other than physical training, the best thing we can do to keep the body reservoir of available glucose up is to keep our digest systems operating as evenly and continuously as possible. Drink mixes are useful for that, between sit-down meals.

  10. Hi Earlylite, are you still using these products on strenuous hikes?

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