Contributed by Hannah Stoker
Environmental factors such as wind speeds, ambient temperature, humidity, precipitation, and altitude play an important role in the athlete’s ability to perform at an optimal level. In this blog we will discuss supporting athletic performance, hypoxic training, and nutritional considerations when faced with environmental obstacles.
Reduced Oxygen & Your Body
During exertion physiological responses are elevated at altitude. Even low to moderate altitudes of 2000-3000 meters above sea level create a hypoxic environment* in which heart rate, respiratory rate, and perceived exertion increase during exercise.
At rest and during physical exertion, the body begins to exhibit an elevated sympathetic tone**. This is a cascade of biochemical events, beginning with a release of epinephrine and cortisol hormones, and resulting in an increased reliance on carbohydrates as a fuel source. In addition, the athletes resting metabolic rate and oxidative stress level are elevated at altitude. This highlights the importance of a calorie-sufficient and antioxidant-rich diet to support high-altitude training.
Extended Hypoxia
Endurance athletes and coaches may seek out extended hypoxic living and/or training to produce desired training adaptations, the most notable of which is erythropoiesis, or the increase in red blood cell count, elevating aerobic capacity.
To assist the athlete in maintaining performance output while in hypoxic environments, Rasa Nutrition recommends adequate nutrition. We focus on a few main nutritional considerations for athletes at altitude: adequate iron stores before initiation of altitude training; adequate overall energy and carbohydrate intake throughout training; sufficient consumption of antioxidant-rich foods to combat the oxidative stress placed on the body; and balanced hydration.
Nutrition & Success
Consuming iron-rich foods before beginning altitude training and throughout the training duration is a great way to maintain adequate iron stores. Rasa Nutrition suggests meals and snacks that include nutrient-dense sources of carbohydrate to meet the body’s increased reliance on carbohydrate as fuel. Fruits and vegetables are great sources of antioxidants and should be included often.
Fluid requirements also increase in hypoxic environments as athletes tend to lose more water volume via sweat and the lungs with increased respiratory rates. Losses in water volume can impair performance as blood volume is reduced, making it more challenging for oxygen-rich blood to be delivered to the muscles and to the skin to offload heat. Reduced blood volume also increases the cardiac output required to maintain any given level of performance and increases perceived exertion of exercise.
You can be strong and train well in high altitude environments by maintaining focus on iron-rich foods, antioxidant-rich foods, adequate carbohydrate intake for energy, and proper fluid consumption. This simple nutrition guidance will put you in the best position to succeed in your high-altitude training or high-altitude competition. YOU CAN do it!
References
1. Burke L, Deakin V, eds. Clinical Sports Nutrition. 4. ed. McGraw-Hill Education Medical; 2010.
*hypoxic environment – a reduced oxygen environment
**sympathetic tone - The condition of a muscle when the tone is maintained predominantly by impulses from the sympathetic nervous system (A Dictionary of Biology » Subjects: Medicine and Health — Clinical Medicine).