The comprehensive exercise program used during Skylab missions was effective in preventing weight loss, maintaining leg strength and leg volume, and maintaining the integrity of muscle systems in general. However, in-flight exercise by no means offers complete protection. Cosmonauts Berezovoi and Lebedev returned from a 211-day flight aboard Salyut 7 in a very debilitated condition. Although they had exercised daily, their muscles were so flabby that, for a week, they were barely able to walk; and for several weeks afterwards they required intensive rehabilitation. Crews will need to exercise at least two hours or more each day on long-duration flights to stay healthy! Some of the exercises they will do includes bicycling, walking on a treadmill, doing resistance exercises, and stretching.

Astronaut Shannon Lucid with Cosmonauts Aleksandr Kaleri and Valeri Korzun

Eating a properly balanced diet is also important. Crews for the Shuttle get to choose what foods they will take with them, but meals must include all four food groups in the correct proportions. Nutritional supplements could help to alleviate some of the mineral losses caused by exposure to the zero-g environment. Visit the NASA-JSC Nutritional Biochemistry Laboratory!

Drug treatments are also being studied to help retention of calcium (calcium regulates hormones) and also to help treat cardiovascular deconditioning. The inclusion of a centrifuge to simulate gravity for short periods of time may help crews counteract ill effects, but a human-sized centrifuge has not yet been designed or tested.
 

Healthy, fresh foods will need to be grown during the long trip to and from Mars. In addition to nutritional benefits, plant chambers and greenhouses stocked with familiar food plants will have psychological benefits for Mars explorers and settlers.
Laura Supra, John Lewis and Vickie Kloeris of the Lunar-Mars Life Support Test Project		Studies in the Advanced Life Support Chamber at NASA included plant growth facilities. Plants give off oxygen, which can be used for human crews; and the carbon dioxide crews exhale can be used to support plant life. Crews in the Life Support Test Project grew lettuce for salads and wheat, which they ground and baked into bread for meals.
The following engineering requirements have been developed to keep astronauts fit and healthy during long-duration spaceflights: Clean air Clean water Waste management Adequate food Long-duration storage of food Processing of flight-grown food Clothes washer Lighting systems Simulation of sunlight In step with circadian (human clock cycles) rhythms Analyzers of particulates and microbes in a potentially hazardous environment  Astronaut Charles (Pete) Conrad in the Skylab shower Questions to think about: If you were a traveler to Mars, list at least three benefits you would get from a small garden of plants. Do you think it would be difficult to exercise every day for at least two hours? What things could you do to make exercising more enjoyable?

Next... Communications and Recreation (pg. 8 of 17)