As most of you know (because I had fun sharing all the amazing photos), I was recently in France for a week of endurance cycling. This training was completed at moderate altitude which made everything more difficult. If you’ve ever raced or trained at altitude, you know what I mean; sleeping is interrupted, appetite swings high & low, metabolism is higher, calorie burn is increased, breathing is shallow, perceived effort is off the charts… My experience with these factors had me focusing on how to combat the negative effects with enhanced nutrition in order to perform my best and reap all the positive effects altitude training can provide. This post is a bit on the current research in the topic of altitude nutrition as well as my personal advice and practice.
It’s no secret that elite athletes frequently turn to training at moderate to high altitudes to improve performances back at lower elevations. The benefits are proven, but to reap those benefits, your body must go through a demanding, high stress period of lower oxygen availability resulting in increased heart rate, metabolic rate, ventilation rate, urination and reduced ability to clear lactate. While there are varying strategies to this training, one thing is clear; it creates unique nutritional demands in order to keep up the ability to perform and recover well under hypoxic conditions. To keep the body performing under this stress, there are a few key nutrition strategies to employ.
Increased calorie needs
Basal metabolic rate (calories burned just to sustain life functions) increases in high altitude conditions up to 27% of normal sea level needs. This is due to activity at any level being more difficult and less efficient (requiring more energy usage for the same task) at high altitudes than at low altitudes. Higher elevations typically mean variable and often colder than normal weather conditions, leading to more calories being used to regulate temperatures and prevent hypothermia. The downside is that appetite can be suppressed (some show up to 40%) in these conditions. Training at very high altitudes (>5000m) can induce anorexia. In addition, normal food availability can be difficult (foreign foods, lacking kitchen supplies) during training camps can lead to under consumption, creating potential performance (and health) issues including energy and nutrient deficiency.
During my week, I found myself hungrier than ever while riding. However, off the bike, being away from my normal foods and completely exhausted after riding 4-10 hours every day led to a general lack of interest in food. Eating in this situation became more planned: I needed to eat based on known needs, not desire, similar to what might happen during a long stage race. I made a point to eat more than I wanted before rides and prepared recovery food for immediately afterwards.
Increased fluid needs
Due to increased respiratory rate (lungs are starving for oxygen and taking frequent, shallow breaths to try to get it), more water is lost with each breath. This leads to an increased need for water day to day. Athletes training in hypoxic conditions are also likely training at an increased duration and intensity which increases sweat losses and therefore fluid needs. Along with respiratory water losses, more water is expelled through more frequent urination. Athletes typically refer to this as ‘altitude bladder’. Combined, these three factors can lead to an additional 2500 ml loss per day and some experts suggest consuming 4-5L/day in these conditions. Aim to be on top of hydration needs at all times; consuming sips often during workouts as well as developing a pre-hydration strategy. Neglecting drinking enough can lead to impaired recovery and decreased performance.
Personally, I aimed to include extra liquids throughout the day like carrot juice with breakfast and tea at night, to keep up with my needs off the bike. To not over dilute my electrolytes while increasing water consumption, I added Klean Athlete Hydration to ride bottles and enhanced off the bike beverages with Lyteshow non caloric electrolyte mix. I do not believe in generic set fluid guidelines as sweat rates vary greatly, so I advise drinking frequently and paying close attention to urine color and aiming to pre-empt thirst sensations.
Increased carbohydrates usage
Research has shown that cyclists might benefit from consuming up to 80% of calories from carbohydrates, possibly up to ~12 g CHO/ kg/day, during this type of training. In addition to helping provide energy for performance, the extra carbohydrate helps the brain to make skilled decisions, leads to better oxygen delivery to tissues, and helps prevent hypothermia. Another benefit of consuming more carbohydrates is that they deliver B vitamins which can assist the body with red blood cell production.
During each ride, I ate a higher amount of carbohydrates from waffles, gels, hydration mix, and bars. Since I was spending several hours (seriously, up to 10 hours) a day cycling, my needs on the bike were very high and I took to riding with a handlebar bag to bring enough fuel along. Off the bike, I relied on carb heavy meals and snacks (cereal, juice, milk, pasta, squash puree soups, and banana chips) to satisfy my needs. Due to my gluten free needs, I packed a large amount of food from home in case my options in France were limited. It is vital to have options you can tolerate and consume during any circumstance.
Endurance athletes, especially females and especially runners, are prone to low iron stores (anemia) due to a variety of factors including excess blood loss, dietary restrictions and increased blood volume. Iron’s main role in the body is to transfer oxygen by way of red blood cells from the lungs to tissues. Physically stressed muscles need more oxygen to perform and lacking iron to get the oxygen there can severely impair performance and recovery. At higher altitudes, the body’s need for iron is increased due to the stimulation of erythropoiesis (creation of RBCs). Boosting red blood cells is the major performance enhancing benefit many athletes train at altitude to achieve but entering the training without iron stores to support these RBCs can be detrimental. Athletes should monitor iron status closely leading up to altitude training and increase amounts of iron providing foods in the diet as well as potentially adding a supplement. Iron isn’t the only nutrient that facilitates the transport of oxygen; B6, folate, and B12 (found mainly in animal products, grains and greens) are also utilized in the process and should be consumed in higher than normal amounts during times of high training stress like altitude training. There is also some interesting research describing how diet affects hematopoietic stem cells (HSCs), cells that sustain blood formation, that shows the potential for high fat diets to impair HSC function, while boosting mitochondrial activity (Co-Q10 assists with this) may promote HSC activity.
Iron intake is a difficult one for me as my Celiac Disease manifests in chronic iron deficiency anemia and I’ve undergone years of intravenous treatment to maintain normal levels. Instead of relying on these pricey, time consuming, and sometimes scary (I’ve experienced a couple of bad reactions to IV iron) treatments, I’ve recently turned to daily supplements. Iron is a tricky supplement as it can cause gastric issues (no athlete needs that!). To avoid this, I get iron throughout the day in my general diet along with two spaced out supplements; SWISSE Wellness CO-Enzyme Q10 supplement along with a Women’s Ultivite that supply 10% and 39% respectively. This helps provide me with a little boost. I also have an appointment a week after my trip to have my iron levels checked to make sure the training didn’t induce any further anemia.
Due to the body’s increased demand for carbohydrates during altitude training, protein intake must be decreased. Training at altitude may stimulate weight loss due to high energy usage and under consumption of calories, which is a favorable training effect for many, especially as this weight loss has been shown to be primarily fat loss. However, some of this loss does come from skeletal muscle which is an adverse effect. To prevent lean tissue loss, it is important to time protein intake to where it is most beneficial; after sessions to stimulate muscle recovery, and during ultra-endurance training to lessen muscle damage. In addition to timing, supplementing with the most beneficial types of amino acids will be helpful. Branched chain amino acids (BCAAs) essential amino acids (those that must be obtained through diet), and beta alanine all show the most promise of potentially aiding performance.
While training in France, my protein intake was definitely lower than normal due to a focus on increased carbohydrate needs. To attempt to get what I needed during exercise, Klean Athlete BCAAs were added to one bottle during rides, and protein shakes along with Power Bar’s Plant Protein & Clean Whey bars were consumed post training as immediate recovery fuel. I have yet to start supplementing with Beta Alanine, but my order for a supplement has been placed as I write this!
This topic is less clear than the others. Research on antioxidant needs of athletes are very divided; some report that supplementation protects muscles and improves recovery from stress while others suggest additional antioxidants prevent normal muscle ‘damage & repair’ system, therefore limiting gains. Some studies have shown that antioxidants in athletes may decline for up to do 2 weeks following hypoxic training. However, the fact these athletes show lower levels of plasma antioxidants may be due to under consumption of calories, especially antioxidant rich produce, during a period of increased needs. Vitamins A, E, and C are the most popularly studied antioxidants, but there are many other substances that possess antioxidant activity and may benefit performance during altitude training such as pine bark, co-enzyme q10 and cordyceps. While supplementing beyond needs may be unnecessary, obtaining a normal amount of antioxidants is useful for overall health.
I agree that it is difficult to consume antioxidants through food during periods of heavy training. When appetite is low and the body requires high amounts of calories, using stomach space for low calorie vegetables isn’t always a wise choice. For times like this, I turned to daily supplements. Each morning I take a SWISSE Wellness CO-Enzyme Q10 supplement along with a Women’s Ultivite that is packed with plant extracts. Adding nutrient loaded 100% fruit and vegetable juices along with smoothies enhanced with plant & adaptogen powdered blends are a valuable method of obtaining antioxidants. I have yet to experiment with pine bark, but might be placing an order for that as well…
In the end, if you’re looking to get all you can out of a training camp or race at higher altitudes, it is crucial to be on top of nutrition needs with special attention to what has been discussed throughout this article. If this seems daunting, enlist the help of a sports dietitian to help you create an individualized nutrition plan. Having your nutrition dialed in during such a physically demanding period will help your body perform, recover and reap the benefits of altitude training.