Can your heart get lazy in space?

Can your heart get lazy in space?

Space Heart: Does Your Heart Take a Vacation in Space?

Can your heart get "lazy" in space? Well, not exactly lazy, but it definitely gets a lot less work to do! Our amazing heart is like a super-strong pump, always working hard to push blood around our bodies, especially against gravity here on Earth. But in space, things are very different, and the heart changes quite a bit.

Floating Blood, Easy Pumping

Think about it: in space, everything floats! Your blood doesn't have to fight gravity to get to your brain or toes. Because there's no "down," blood moves more easily around your body. This means your heart doesn't have to pump nearly as hard. It's like a weightlifter suddenly having no weights to lift – their muscles wouldn't need to be as strong!

Shrinking Heart: Less Work, Less Muscle

Just like any muscle, if your heart doesn't work as hard, it doesn't need to be as big or strong. Over time in space, the heart actually gets a little smaller and weaker. This is called "cardiac atrophy." It's the heart's way of adapting to the easier life in microgravity. While this makes sense in space, it can be a challenge when astronauts come back to Earth.

Heart's "Workout": Staying Strong for Earth

When astronauts return to Earth, their heart suddenly has to work hard against gravity again! A heart that's gotten used to an easy life might struggle a bit at first. That's why astronauts do lots of special exercises while they're in space, like riding a stationary bike or lifting weights. These "space workouts" help keep their hearts and muscles strong, making sure they're ready to jump back into Earth's gravity with a strong, healthy pump!

Key References:

·         Levine, B. D., & Convertino, V. A. (2019). The Cardiovascular System in Spaceflight: Effects of Gravity and Microgravity on the Heart and Circulation. Comprehensive Physiology, 9(3), 1145-1194. (A comprehensive review article that covers cardiac atrophy).

·         Hughson, R. L., & Perry, B. G. (2007). Cardiovascular Adaptation to Spaceflight. In Human Physiology in Space (pp. 39-55). Springer, New York, NY. (Discusses the heart's response to reduced workload in space).

·         NASA Human Research Program: Similar to the first essay, NASA's public resources on cardiovascular health in space provide excellent background.1

o    Example resource: Information on "Cardiac Atrophy" and "Exercise Countermeasures" within the Human Research Program.