When you climb to high altitudes, your body faces some serious challenges. The thin air, cold temperatures, and lower oxygen levels make everything more difficult. But did you know that these conditions also put a strain on your energy and water balance? Here’s how your body works hard to keep you going in these extreme environments, as explored by Klaas R. Westerterp in his article “Energy and Water Balance at High Altitude.”
Energy at High Altitude: Burning More, Eating Less
At high altitudes, your body’s energy demands spike. The cold environment and the effort required to move in low-oxygen conditions push your energy expenditure up. Westerterp highlights that basal metabolic rate (BMR) can increase by up to 10-20% at altitudes above 4,000 meters due to cold exposure and increased sympathetic nervous system activity. But here’s the tricky part: many people lose their appetite at high altitudes, a phenomenon known as altitude anorexia. As a result, your energy intake often drops, leading to a negative energy balance where your body burns more than it takes in.
This imbalance can lead to significant weight loss. According to Westerterp, climbers at high altitudes can lose up to 5 kg in just a few weeks, with the loss coming from both fat and muscle tissue. This weight loss can weaken your body and make it harder to continue your activities.
Water Balance: Staying Hydrated is Harder
Maintaining proper hydration is another major challenge at high altitude. The air is much drier, and as you breathe faster to get more oxygen, you lose more water through respiration. Westerterp notes that water loss through breathing alone can increase by about 200 ml per day at high altitude. Moreover, cold weather can cause your body to expel more water through urine – a process known as cold-induced diuresis. Combined with a reduced sensation of thirst, this puts you at a high risk of dehydration.
Dehydration can have severe consequences, exacerbating symptoms of altitude sickness and reducing your physical and mental performance. Westerterp emphasizes the importance of monitoring your fluid intake and ensuring you drink enough water, even when you don’t feel thirsty.
How Your Body Adapts
Your body does its best to adapt to these harsh conditions. Over time, it undergoes physiological changes to improve oxygen utilization and energy efficiency. For instance, your body increases the production of red blood cells to carry more oxygen, and it enhances the efficiency of your mitochondria – the powerhouses of your cells – to produce energy with less oxygen. These adaptations are crucial for long-term survival and performance at high altitude.
Westerterp also discusses how hormonal changes, such as increased levels of catecholamines, help regulate metabolism and fluid balance, further aiding in adaptation to high-altitude environments.
Takeaways for High-Altitude Adventures
If you’re planning to spend time at high altitude, it’s essential to pay close attention to your energy and water intake. Eating enough – even when you don’t feel like it – and staying hydrated are key to keeping your body strong and healthy in the mountains. Westerterp’s research underscores the importance of preparing for the physical demands of high altitude, including acclimatization strategies to give your body time to adjust.
In short, surviving and thriving at high altitudes is all about balance, keeping your energy up and staying hydrated to meet the demands of the environment. By understanding how your body responds to these challenges, you can better prepare for your next adventure, ensuring that you stay strong and healthy in the heights.