Physical Fitness and Gravity

John Creighton · 2005-08-19 18:11:21

I am going to start this thread by saying I think the body is adaptable to many environments and I don’t think there is any reason we cannot live in any gravity level without special measure. I also don’t think it will be impossible to come back to earth after even living at zero G for long periods of time.

That said I would like to start proposing some models because I believe well we can adapt it is important to know how quickly we will adapt both to lower and higher G environments. Now I will present some conjecture that can be tested against the current data to help better understand the process.

When a mussel fiber is damaged the whole fiber is repaired uniformly As a consequence when the stress is reduced enough in the damaged portion of the fiber for the mussel to stop sending repair signals the whole muscle will be stronger then the original.

A mussel releases messages that it needs to be repaired only when it is stressed. The intensity of these messages depends on the level of physical excretion. Thus the intensity will be lower when someone is lying down then when they are sitting on a chair, it will be greater still when they are walking and even greater when they are exercising. Because rips in the mussel fiber increase the stress in the mussel during everyday activities from sitting walking to laying down, this means that exercise will have a residual effect in terms of the signals sent. Moreover the extent of this residual effect will depend on gravity. Thus I propose that it is not the exercise in the centrifuge that is beneficial rather the residual effect during recovery.

There is a biological limit to the rate mussel fibers can be repaired. This means that if a person exerts himself beyond the rate the body can repair the damage to the mussel fibers then the individual will get no gain from the exercise.

John Creighton · 2005-08-19 18:44:19

Okay, after making my post I have done some reading to see if my conjectures are any good. While I haven’t found anything to prove or disprove my conjectures I found the following very interesting:
http://www.firstscience.com/site/articles/gravity.asp
Some quotes:

The muscles used to fight gravity - like those in the calves and spine, which maintain posture - can lose around 20 per cent of their mass if you don't use them. Muscle mass can vanish at a rate as high as 5% a week.
For bones, the loss can be even more extreme. Bones in space atrophy at a rate of about 1% a month, and models suggest that the total loss could reach 40 to 60 per cent.

So it appears that you won’t lose more then 20% of your mussel mass if you you odn’t use them. Similarly you don’t lose more then 40% of your bone mass. I find the rates interesting to, so from that I should be able to make reasonable predictions about mussel loss.

But that shift in blood pressure also sends a signal. Our bodies expect a blood pressure gradient. Higher blood pressure in the head raises an alarm: The body has too much blood! Within two to three days of weightlessness, astronauts can lose as much as 22 percent of their blood volume as a result of that errant message. This change affects the heart, too. "If you have less blood," explains Dr. Victor Schneider, research medical officer for NASA headquarters, "then your heart doesn't need to pump as hard. It's going to atrophy."

This is interesting. I think that the amount of blood you have must effect how quickly you can repair your mussels and how much calcium your bones can absorb. Perhaps we need to do some experiments about the effects of blood pressure on bone and mussel mass on mice.

Yet another promising device attempts to mimic gravity even more closely. Hargens and his colleagues are developing a Lower Body Negative Pressure (LBNP) device, a chamber that contains a treadmill, and that relies, says Hargens, on the suction of an ordinary vacuum cleaner. "We've found," he says "that we can provide body weight by applying negative pressure over the lower body."

One reason is that the LBNP allows astronauts to exercise with an effective body weight between 100% and 120% of what they would feel on Earth. Another is that - unlike any previous exercise device - it restores the blood pressure gradient, increasing blood pressure to the legs.

Wow could it be so simple, just build a suite that they wear all day that simulates gravity by creating a pressure gradient on the body?

SpaceNut · 2005-08-19 19:04:22

just build a suite that they wear all day that simulates gravity by creating a pressure gradient on the body?

Basically that was sort of the idea in the following post under space suits.

An outfit suitable for Mars Slimmer space suits on the wrack for astronauts.
The gas-pressurized space suits used by astronauts for space walks and moon landings would never work on Mars. That's the consensus, at least among astrobiologists and simulation experts at the Eighth International Mars Society Convention, which took place 11-14 August in Boulder, Colorado.
The Mechanical Counter Pressure (MCP) suit image
aims to use elasticity to provide pressure instead. Paul Webb, a physician from Yellow Springs, Ohio originally proposed this idea in 1968, as a safer and more flexible alternative to the bulky Apollo mission suits. His idea didn't take flight until recently, however, when the US space programme began casting an eye towards the red planet.

John Creighton · 2005-08-19 19:14:59

just build a suite that they wear all day that simulates gravity by creating a pressure gradient on the body?
Basically that was sort of the idea in the following post under space suits.
An outfit suitable for Mars Slimmer space suits on the wrack for astronauts.
The gas-pressurized space suits used by astronauts for space walks and moon landings would never work on Mars. That's the consensus, at least among astrobiologists and simulation experts at the Eighth International Mars Society Convention, which took place 11-14 August in Boulder, Colorado.
The Mechanical Counter Pressure (MCP) suit image
aims to use elasticity to provide pressure instead. Paul Webb, a physician from Yellow Springs, Ohio originally proposed this idea in 1968, as a safer and more flexible alternative to the bulky Apollo mission suits. His idea didn't take flight until recently, however, when the US space programme began casting an eye towards the red planet.

Yeah, that should work provided you provide more pressure to the head and torso then you do the legs.

Grypd · 2005-08-20 06:32:46

One option is that we will use drugs that block the signals that reduce muscle mass and the cause of calcium loss. There is a lot of research into this already as it is a common affliction for elderly and a cure would benefit them too.

There is also a possibility that in the future some of the people we will send will actually be looking for the reduced G as they will have weakenesses in their own bodies that cannot be cured. And there only chance of a decent life

Stormrage · 2005-08-21 04:58:08

Or you could study gravitions and see if you can create artifical gravity like Star Trek.

SpaceNut · 2019-03-17 11:53:00

not just for exercise for staying healthy but for purpose as well to do work...

Mars_B4_Moon · 2022-07-02 17:19:04

Astronauts suffer 'significant' bone loss during space missions - raising concerns for future trips to Mars
https://www.iwradio.co.uk/news/video/as … s-to-mars/

Fully Robotic Surgery May Depend on Elon Musk’s Mars Mission
https://www.forbes.com/sites/johnkoetsi … n-to-mars/

Mars_B4_Moon · 2023-12-12 13:40:33

8 US space stations designed to succeed the International Space Station
https://interestingengineering.com/list … ations-iss

for now, looking outside the adverts and hype I believe Japan could be the most interested in launching some kind of station with animals to examine creation of an inertial force that mimics the effects of a gravitational force but there is also a US company making Haven and Vast-1. It has been part of scifi for many years and Several proposals have come and gone but Japan seems to be serious and maybe the US Private Company.

Mouse Habitat Unit (MHU)
https://iss.jaxa.jp/en/kiboexp/pm/mhu/

2017

Development of new experimental platform 'MARS' - Multiple Artificial-gravity Research System - to elucidate the impacts of micro/partial gravity on mice
https://iss.jaxa.jp/en/kiboexp/news/170926_mars_en.html

Ground-based assessment of JAXA mouse habitat cage unit by mouse phenotypic studies
https://www.jstage.jst.go.jp/article/ex … e/-char/en

Mouse Habitat Experiment
https://spaceflight101.com/iss/mouse-ha … xperiment/

The Japanese Mouse Habitat Experiment in some ways is similar to the U.S.-led Rodent Habitat set up on the Space Station in 2014, however, there are a number of significant differences including the use of artificial gravity and the accommodation of one mouse per cage for individual studies of behavioral changes. The Mouse Habitat Experiment consists of two major segments, the main Onboard Cage Unit for the accommodation of mice for 30 to 180 days and Transportation Cage Unit that accommodates the animals for up to ten days from launch to transfer to ISS and from the end of the ISS-based experiment to the return to Earth aboard a visiting vehicle.

claim that the maximum gravitational field humans could survive long-term is four-and-a-half times the gravity on Earth?

https://arxiv.org/abs/1808.07417

Both approaches conclude that, with rigorous training, humans could perform normal locomotion at gravity no higher than 4 g Earth.

Vast Space a privately held US aerospace company founded by entrepreneur Jed McCaleb states he has the goal of developing artificial gravity space stations to "expand humanity beyond the solar system"
In 2023 Vast launch an Orbiter aboard SpaceX's Falcon 9 rocket on their Transporter-8 mission
https://www.geekwire.com/2023/spacex-st … satellite/
info on 'Orbiter SN3'
Vast received a Collaborations for Commercial Space Capabilities-2 (CCSC-2) agreement from NASA to help develop artificial gravity stations a few days later. Vast announced that it had selected Impulse Space to develop Haven-1's propulsion system.
https://www.voxelmatters.com/vast-selec … ropulsion/
,
https://web.archive.org/web/20230621044 … velopment/

Haven-1 claim that crews aboard the station will conduct experiments in an attempt to mimic the amount of gravity the Moon has

Vast-1 is expected to launch on a Falcon 9 rocket, using a Crew Dragon vehicle, both manufactured by SpaceX
https://techcrunch.com/2023/05/10/vast- … t-in-2025/
,
https://spacenews.com/vast-announces-pl … e-station/

Last edited by Mars_B4_Moon (2023-12-12 13:41:23)

Mars_B4_Moon · 2024-06-12 04:45:43

ESA and Vast to study cooperation on future commercial space stations

https://spacenews.com/esa-and-vast-to-s … -stations/

New Mars Forums

Announcement

#1 2005-08-19 18:11:21

Re: Physical Fitness and Gravity

#2 2005-08-19 18:44:19

Re: Physical Fitness and Gravity

#3 2005-08-19 19:04:22

Re: Physical Fitness and Gravity

#4 2005-08-19 19:14:59

Re: Physical Fitness and Gravity

#5 2005-08-20 06:32:46

Re: Physical Fitness and Gravity

#6 2005-08-21 04:58:08

Re: Physical Fitness and Gravity

#7 2019-03-17 11:53:00

Re: Physical Fitness and Gravity

#8 2022-07-02 17:19:04

Re: Physical Fitness and Gravity

#9 2023-12-12 13:40:33

Re: Physical Fitness and Gravity

#10 2024-06-12 04:45:43

Re: Physical Fitness and Gravity

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