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Protein for Endurance

Colin Riley and Aaron Scheidies riding a tandem bike, text "Using Protein in your endurance Blend"

Colin's Career Highlights:

2013 USA Triathlon Overall Age Group National Champion 2013 Best of the US Amateur National Champion

2014 Chicago Marathon: 2:52:45 (Boston Qualifier)

2015 Carlsbad Half Marathon: 1:15:56

2015 ITU Age Group World Championships - Sprint Distance - 3rd Overall - 1st American

2015 ITU Age Group World Championships - Olympic Distance - 5th overall

2016 Des Moines Triathlon (Pro race) - 5th Overall


When it comes to protein, most people think about weight training, big muscles and "bulking-up". Do endurance athletes need protein DURING training and racing? The answer is maybe... Let's take a closer look at the ins and outs of protein for endurance athletes during training and racing. 

Here at INFINIT, our philosophy is that there is no need for bars or solid food even if you're doing an Ironman, 24 hour mountain bike race, or even an ultra-marathon or long open water swim! With no bars or solid food, that's where the protein comes in.

Ironman and 70.3

For an an Ironman and half Ironman distance, we recommend two different blends. One "BIKE" blend and one "RUN" blend. The BIKE blend will be your go-to blend for all of your endurance rides 3 hours and over in duration. We recommend putting 2-4 grams of protein in the BIKE blend to help curb hunger. The RUN blend however, should not contain any protein as protein is more difficult to digest and can lead to some gas and other GI issues while running.

Endurance Cycling


For cyclists competing in road races, 8/12/24 hour mountain bike races, and other events over 3 hours in duration, protein will be key to keep the hunger at bay. The same general guideline follows with about 2-4 grams of protein per serving. Some mountain/gravel riders riding technical courses with steep climbs may have a harder time with the full 4 grams of protein and may need to cut it back to 3 grams per serving. When you're going up a steep climb and your heart rate is elevated, it can be a little more difficult to digest the protein in the blend so scaling it back one gram can be helpful. 


Ultra-marathon and Long Open Water Swimming

Usually for running and swimming we don't advise protein as it can be more difficult to digest and may lead to some gas and GI issues. However, for those athletes that are running beyond the marathon distance and swimming over 10k, a small amount of protein may be helpful so that you can stick to an all liquid nutrition plan without getting hungry. For ULTRA running and swimming blends, we typically recommend around 0.5-2 grams of protein per serving. Some ultra runners/swimmers will cycle back and forth between a protein containing blend and a non-protein blend. 


For those of you that are doing shorter distance triathlons (sprint and Olympic), running races up to the marathon distance, as well as shorter cycling events such as criteriums, a blend WITHOUT protein should suffice as hunger is usually not an issue during these relatively shorter races. For these types of races, we would recommend a SPEED or "RUN" type blend.


For an athlete with diabetes who may be competing in some shorter distance races, a small amount of protein may be added to their custom blend to help with blood sugar control as protein tends to slow down the overall digestion process just a little bit which could help stabilize blood sugar levels.


Some of you may still be wondering how an all-liquid nutrition plan will keep you from not getting hungry?

Well, for comparison, many bars have around 10 grams of protein each and many athletes will eat one bar every 2.5 - 4 hours which would be about 2.5 - 4 grams of protein per hour. Most of our top professional athletes are successfully using INFINIT exclusively for marathon fueling, such as at the Ironman distance as well as 24 hour mountain biking, and ultra-running and swimming races too!


Compared to some of the other sports drinks on the market with protein for endurance, INFINIT uses a far lower amount (2-4 grams versus 7-14 grams) which keeps the protein from affecting the flavor and palatability of your drink. In fact, other than its effect on minimizing hunger, you probably will not even be able to tell that there is protein inside your mix. We use a pure whey protein isolate for endurance in our custom blends that mixes easily and holds up in the heat.