# Have there been any studies on the health impacts of prolonged high G?

If you are flying to Mars or elsewhere, and you want to use a centrifuge to 'make 1G' to keep the passengers healthy, why not increase it (slowly) so they are actually at 2G's? Seems like this would make the passengers stronger.

Does higher gravity = more healthy?

• Mass constraints is a reason not to. Doubling the radius of a spin hab makes it more massive. Also puts more pascals on the spokes which means a sturdier structure is necessary. It may be that less than a g can keep the astronauts healthy. To get the astronauts used to Mars gravity, that's what I'd set the spin hab for Mars bound astronauts. – HopDavid Sep 25 '15 at 16:09
• @HopDavid good points, but why not just spin the hab faster rather then make it bigger? – James Jenkins Sep 25 '15 at 16:13
• There's some controversy to how many rpm's humans can work comfortably in. DiZio and others seem to believe we can get used to 4 or 5 rpm's. Artificial gravity is $\omega^2r$ so doubling angular velocity gives us 4 times as much weight. But while ramping up $\omega$ may cut needed radius, more newtons still means more massive structure. – HopDavid Sep 25 '15 at 22:09

Contrary to small animals, now that the human being has stand up on their feet, their brain is located much higher than their heart, but the brain still continuously needs blood.

Under increased vertical acceleration, the blood pressure must be increased to maintain brain irrigation. This has been studied in the past:

The Biology of Human Survival: Life and Death in Extreme Environments, Claude A. Piantadosi:

Human volunteers have tolerated 1.5g for seven days with no apparent ill effects. However, after just twenty-four hours at 2g, evidence of significant fluid imbalance is detectable. At 3g to 4g fatigue is limiting, and above 4g cardiovascular factors limit g tolerance.