Portuguese 
English 
Spanish 
4 min of reading 
0 comments 
Brief exposure to simulated microgravity already causes rapid changes in the human body, affecting circulation, metabolism, and internal balance, with differences between men and women that raise alerts for space missions and medical applications on Earth.
Five days were enough to cause measurable changes in different systems of the body of healthy adults subjected to an experiment that reproduces, on land, some of the effects of microgravity.
Published in the journal Communications Medicine, the study gathered men and women exposed to the technique known as dry immersion and identified an acute deconditioning with cardiovascular, metabolic, and fluid regulation impacts.
What happens to the body without gravity
By removing the usual mechanical support from the body, the research shows that the organism begins to reorganize rapidly, even when exposure occurs for a relatively short and controlled period in an experimental environment.
-
Essential medication in some hospitals and urgent change in treatments for cancer and autoimmune diseases in Brazil.
-
An extratropical cyclone forms on the southern coast of Brazil and brings gusty winds, heavy rains, and a drop in temperature from Rio Grande do Sul to Santa Catarina throughout the week.
-
Engineers are pulling cold water from a deep lake to transform an entire university into a cooling system that looks like science fiction, using underground pipes and heat exchangers to cool the campus with natural cold.
-
ESA launches the first mission in history with two satellites capable of creating artificial solar eclipses in space and technology designed to usher in a new era in the observation of the solar corona: meet Proba-3, equipped to fly in millimeter formation and maintain precise shadow for hours.
In this context, worsening of orthostatic tolerance, reduction in the ability to maintain an upright position without discomfort, and changes in markers associated with metabolism and bone health were observed.
Gathering data from two campaigns of the European Space Agency, ESA, called VIVALDI-1 and VIVALDI-2, the work expanded the understanding of how these responses manifest in men and women.
Thirty-seven healthy volunteers participated, including 18 women and 19 men, monitored before, during, and after the experiment with detailed physiological measurements.
Among the indicators evaluated were hormones, fluid redistribution, aerobic capacity, muscle strength, venous function, body composition, glucose metabolism, lipid profile, bone remodeling, and vascular responses.
How the dry immersion technique works
During the protocol, volunteers lie down in structures resembling bathtubs, suspended by a waterproof fabric that prevents direct contact with water while keeping the body partially immersed.
With this setup, there is a significant reduction in mechanical load on muscles and support structures, reproducing typical conditions of microgravity, such as absence of physical support, hypokinesia, and redistribution of body fluids.
In addition to simulating the space environment, the model allows for precise observation of the organism’s behavior over the days, without relying on orbital missions, which are more complex and limited in terms of scientific access.
Multisystem deconditioning in a few days
As the main finding, the study confirmed an acute multisystem deconditioning, highlighting that different systems of the body are affected simultaneously, rather than in isolation, when exposed to this type of condition.
In this scenario, significant changes were identified in the cardiovascular, metabolic, and fluid regulation systems, forming a set that compromises physiological stability in a short period of time.
Thus, the results help explain why returning to Earth’s gravity can pose a challenge, even after relatively brief exposures to environments that replicate the physical logic of space.
Orthostatic tolerance and risk when returning to gravity
Among the observed effects, the decrease in orthostatic tolerance stood out, representing the body’s ability to maintain adequate circulation when assuming an upright position without presenting symptoms such as dizziness or drops in blood pressure.
When this mechanism is compromised, the risks of circulatory instability increase, which can directly impact safety and performance in situations that require rapid adaptation to gravity.
In the experiment, this tolerance was reduced after five days of immersion, with a more pronounced impact among women, indicating possible relevant physiological differences in this type of response.
Considering that readaptation to gravity is one of the most critical phases after staying in a space environment, the data reinforces the need for more effective preventive strategies.
Differences between men and women
When analyzing responses by sex, the research identified specific differences in metabolic and bone parameters, although the overall pattern of changes was similar between men and women.
Among the participants, a greater elevation of the plasma atherogenic index, an increase in bone resorption markers, and signs of reduced insulin sensitivity were observed.
Even with these differences, the authors point out that many physiological responses are shared, suggesting a common basis for adaptation to the simulated microgravity environment.
Still, the findings indicate that future countermeasures may need to consider distinct biological characteristics to ensure greater efficacy.
Impacts beyond space exploration
Although the main focus is on space exploration, the experiment also contributes to the understanding of phenomena observed in clinical situations on Earth, especially those related to prolonged immobility.
The protocol was structured to assess factors directly linked to physical performance and physiological safety, including muscle strength, aerobic capacity, body composition, and vascular function.
When analyzed together, this data reveals a systemic reorganization of the organism, showing that the absence of gravitational load affects multiple processes in an integrated manner.
Furthermore, the results reinforce the role of gravity as a constant element in maintaining physiological balance, influencing functions that normally operate without conscious awareness in daily life.
With the reduction of this stimulus, the body undergoes rapid adjustments that impact circulation, metabolism, and postural stability.
In this context, dry immersion consolidates as a relevant tool to investigate physiological adaptations, allowing for the anticipation of risks and testing strategies before their application in space missions or clinical scenarios.
By integrating data from the two VIVALDI campaigns, the study expands the available scientific base and demonstrates that, in just five days, changes in circulation, metabolism, postural response, and bone markers are already detectable.
Seja o primeiro a reagir!