Nutrition is a lot like politics… If you find yourself going too extreme in any direction, you’re probably going to make Thanksgiving weird. A few years back I went vegan for 365 days while racing full time and I learned a lot about this trendy diet/lifestyle. Mainly, I learned it doesn’t work for elite level mountain biking. Let me explain…

First off, I love a lot about veganism on both the nutritional side of the diet as well as on the more philosophical side. However, if there’s one thing the constantly changing headlines about ‘what to eat’ and ‘what not to eat’ has taught us, it’s that nutrition is complex and drawing a hard line around any single diet or fad is probably going to leave you with a few blind spots. These are the one’s I found:

Bio Availability

Yes, you can get all macro and micro nutrients the human body needs from plants. However, all forms of macro and micro nutrients are not created equal, nor are they packaged the same in the food source. Typically, plant sources are fewer, much harder to unpack, and more difficult to use. The two most serious issues here for endurance athletes are iron and protein. Let’s start with protein…

Every single animal-source of protein is what’s called a “complete protein”. This means it contains adequate amounts of all 9 essential amino acids that the body needs. Dairy, eggs, fish, poultry, etc. are built of similar proteins to that of the human body and therefore provide starving/damaged muscles from a gnarly ride everything they need, quickly and efficiently.

Plants are “incomplete proteins” because they lack one or more of the essential amino acids. Further, they have, on average, a significantly lower percentage of protein to total mass than animal sources. This means plant proteins need to be combined together to ensure all essential amino acids are being obtained and often need to be taken in supplement form in order to ensure starving post-workout muscles are getting enough. A similar dilemma can be seen with iron.

Iron deficiency is the world’s most common nutritional disorder and this is especially true with endurance athletes due to the rapid production and loss of red blood cells for oxygen delivery. There are two types of iron – heme, and non heme. Heme iron is found in animal proteins and has a very high bioavailability (an absorption rate of up to 25%). Non heme iron is what is found in plants and supplements. Plants on average already have significantly less iron compared to animal foods, and on top of this non heme bioavailability is only around 3-15%.


Due to a lower quantity and bioavailability of key nutrients in plants as well lower caloric density, consuming 5,000-6,000 calories of vegan cuisine on a big training day can be tricky. The reason here is endurance athletes already need more protein and micronutrients than the average person. As discussed above, plant sources of food provide less of both of these. Because of this, everything consumed on these big training days needs to be nutritionally dense and/or a ton of supplements need to be consumed.

Now because of how important it is to use each calorie to help meet amino acid and micro nutrient needs when dealing strictly with plant-based foods alone, “empty calories” like rice or pasta are a bad choice. However, nutritionally dense plant foods like leafy greens, legumes, and super-grains like quinoa are packed full of fiber. This means even more needs to be consumed since fiber provides no calories. Further, too much fiber is a sure way to upset the stomach, especially while training.

Limited Options

Finally, the practicality of veganism for a competitive cyclist just isn’t there. The planning, food prep, supplementation, and nutrient counting necessary to do it correctly and maintain a high level of fitness on the bike is a full-time job by itself. Once you bring travel and big training rides into the mix, it’s impossible.

The first time I went to Germany for 2 weeks to train/race while on this diet I ran into this dilemma instantly. In a little village hours from any major city, I realized I was going to have to choose between veganism or staying alive because rice, spring mix, and an ungodly amount of beans just won’t cut it between 5 hour rides.


In Conclusion…

My time as a vegan led to the lowest weight of my adult life (128 lbs). You’d think my power:weight ratio would’ve been insane, but I was also the weakest I had ever been in my adult life. My power on the bike was terrible, I was tired all the time, and always in a dull or flat out irritated mood. My cholesterol became unhealthily low, I was dipping in and out of vitamin D and iron deficiencies, and I could clear out a whole airport terminal as a byproduct of all the legumes I was consuming.

I will note that the most success I found with veganism was when I geared it towards a ketogenic diet. While the need for pretty intense supplementation was still there, deriving most of my calories from fat allowed me to finally get enough energy without having to consume huge amounts of “heavy”, fiber-dense foods. Still, ketosis was not a solution to my lack of power. While I could easily bust out a mellow 5 hour ride, I had no high-end intensity which made racing a serious struggle.

I’m well aware there are 10,000 “solutions” within the realm of veganism to the problems I’ve listed in this blog. However, I consider none of them practical. A diet that requires an athlete to take dozens of supplements per day, only shop at specialty/boutique grocery stores, and undertake regular blood work to test for malnutrition is simply a flawed diet.

I view animal products the same way I view most grains… In general, I would agree with vegans in that they are not a necessity. They are a supplement. Egg whites, poultry, fish, shellfish, whey protein, etc. have a place in my diet when I’m unable to get all of the nutrients I need during big training cycles. Same with other non-vegan items like many energy bars, breads, and pastries.

In my experience, the best diet for an athlete is one of balance, acceptance (athletes travel and the exact thing you feel you need to eat will often not be available), and constant self-assessments. Being mindful of what you consume and how it makes you feel is key so that you can constantly fine-tune not only what you’re eating but also when and how much in order to achieve wellness and maximum performance.


Thanks for reading! I know we really just skimmed the surface here, so let me know what you’d like me to expand on more or other sports nutrition topics that would be of interest to you.