Interim Resistive Exercise Device (iRED) - 12.03.13
Science Objectives for Everyone
Long duration exposure to micro-gravity causes muscle atrophy, loss of strength and deterioration of bone mass. A key element in the crew countermeasures will be to provide resistive exercise to prevent this kind of deterioration. The Interim Resistive Exercise Device (IRED) is designed to prevent atrophy of the major muscle groups and to minimize bone loss in the zero gravity environment by maintaining strength, power, and endurance.
Science Results for Everyone
Johnson Space Center, Houston, TX, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)ISS Expedition Duration
March 2001 - September 2011Expeditions Assigned
2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19/20,21/22,23/24,25/26,27/28Previous ISS Missions
- The interim Resistive Exercise Device (iRED) is used onboard ISS to aid in the maintenance of muscular strength. Crewmembers exercise daily on iRED to maintain their preflight muscle and bone strength and endurance. iRED is retired as of October 2011, and its replacement is the Advanced Resistive Exercise Device, or ARED, which was taken to the International Space Station on space shuttle mission STS-126 in November 2008.
- On ISS, the iRED can be configured to allow performance of at least 18 different exercises for both upper and lower body muscles.
- The iRED provides a load of up to 300 pounds of resistive force for countermeasure exercise. Resistive exercise helps astronauts maintain strength and endurance.
- The iRED accommodates all crewmembers, from the 5th percentile Japanese female to the 95th percentile American male.
- Squat Harness is used to perform squats, straight-leg Deadlift, bent-leg Deadlift, and heal raises.
- Short Bar Assembly is used to perform straight leg deadlifts, bent-leg deadlifts, bend-over rows, upright rows, bicep curls, shoulder presses, sit-ups, bench presses and wrist curls.
- Hand cranks are used to adjust the resistance.
- Hand grips used to perform hammer throws, shoulder raises, shoulder presses, bicep curls, tricep extensions, wrist curls, bent-over rows, and upright rows.
- Ankle cuffs used to perform hip abductions / adductions, knee raises, and leg curls.
- Resistance - Each IRED canister shall provide a maximum resistive load of at least 150 pounds at the highest load setting. With two canisters the maximum resistive load will be 300 pounds. At the lowest load setting, each IRED canister shall provide a resistive load not to exceed 30 pounds.
- Adjustability - For resistances of 100 pounds or less, adjustability shall be in increments of five pounds resistance at an accuracy of 1 pound or +5% of current reading, whichever is greater. For greater than 100 pounds, adjustability shall be in increments of 10 pounds resistance at an accuracy of 1 pound or +5% of current reading, whichever is greater.
- iRED has been stowed and occasionally used in its current mode of operation as a contingency to ARED
- The iRED contains a series of 16 flex packs stacked vertically inside cylindrical canisters and is designed to provide resistance training for crewmembers in microgravity. A flex pack consists of a ring disk aluminum outer rim, with rubber spokes protruding inward toward a center hub.
- The flex packs revolve about a metal axle. When the metal axle is turned, the rubber spokes are stretched, increasing the resistance offered by the device.
In order to assess the effectiveness of the proposed countermeasure, ground reaction forces, muscle forces, and joint reaction forces must be compared to iRED and normal 1-G activity. If countermeasure exercise is capable of exceeding the loading environment created when the iRED is used in microgravity, then muscle and bone strength might be maintained to a greater extent than currently observed with astronauts on the ISS. The maximum ground reaction force (GRF) per leg, which was produced from two-legged squats on iRED in parabolic flight, was 76 lbs, or nearly 0.5 body weight (BW). GRFs produced per leg during a one-legged squat were 144% higher than from a two-legged squat using iRED. Similarly, GRFs from two-legged squats were 33% higher than from two-legged squat on iRED. The largest GRF experienced by the subject in this study was 1.2 BW. Peak GRF experienced when walking in 1-G is 1.5 BW. When accounting for the maximum 0.5 BW that is added to simulate a vibrating platform (peak GRF = 1.7 BW), the GRF of this study exceeds that of 1-G walking. In a recent study, average single leg forces for two-legged squat using iRED on the ISS was found to be 0.59 BW, and that for one-legged squat was found to be 0.64 BW. Simulated vibration exercise was confirmed to be a highly effective stimulant for both muscle and bone, as demonstrated by the considerable increase in muscle forces and joint reaction forces. Vibration could offer the necessary stimulus to further attenuate muscle degradation as well as preserve bone density. Current countermeasures on the International Space Station (ISS), such as resistive exercise on the interim Resistive Exercise Device (iRED) or Advanced Resistive Exercise Device (ARED), treadmill running, and cycling, have only proven to be partially beneficial despite over four decades of optimization. In particular, astronauts returning from six months aboard the ISS have shown that anti-gravity muscle volume and peak power still decrease significantly versus pre-flight (-13% and -32%, respectively). Bone mineral density (BMD) and strength losses also persist in the lower extremities with integral hip BMD being lost at an average of 1.5% per month. Such losses must be blunted to ensure safety of astronauts for extended duration excursions beyond low-Earth orbit (Goel et al. 2012).Results Publications
Goel , Kaderka , Newman DJ. Modeling the benefits of an artificial gravity countermeasure coupled with exercise and vibration. Acta Astronautica. 2012; 70: 43-51. DOI: 10.1016/j.actaastro.2011.07.021.
Ground Based Results Publications
NASA Image: ISS010E05354 - Astronaut Leroy Chiao, Expedition 10 commander and NASA ISS science officer, uses the short bar for the Interim Resistive Exercise Device (IRED) to perform upper body strengthening pull-ups. The iRED hardware is located in the Unity node of the International Space Station (ISS).
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NASA Image: ISS017E006639 - NASA astronaut Garrett Reisman, Expedition 17 flight engineer, wearing squat harness pads, performs knee-bends using the Interim Resistive Exercise Device (IRED) equipment in the Unity node of the International Space Station.
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NASA Image: S112E05165 - Mission specialist Sandra Magnus and Expedition 5 Science Officer Peggy Whitson are photographed in the International Space Station (ISS) Node 1/Unity module working with the Interim Resistive Exercise Device (IRED) and Handcrank Assembly - Fore.
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