The Advanced Resistive Exercise Device (ARED) uses adjustable resistance piston-driven vacuum cylinders along with a flywheel system to simulate free-weight exercises in normal gravity. Studies have found that without exercises like those possible on the ARED, astronauts could lose up to 15% of their muscle volume, which could be difficult or even impossible to regain back on Earth. ARED's primary goal is to maintain muscle strength and mass in astronauts during long periods in space.Facility Manager(s)
Facility Developer(s) Information PendingSponsoring Agency
National Aeronautics and Space Administration (NASA)Expeditions Assigned
18,19/20,21/22,23/24,25/26,27/28,29/30,31/32,33/34,35/36Previous ISS Missions
The predecessor to ARED, iRED began ISS operations during Expedition 2.
ARED consists of seven distinct assemblies:
Exercise Platform Subassembly mounts to the ARED structural frame and provides the surface from which to perform exercises. The platform houses two force plates, which act as the reaction surface for all exercises. Four load cells are installed under each force plate to measure the reactive loads. At this test level, the eight load cells and associated wiring harnesses have been installed.
Cylinder / Flywheel Assembly provides the resistive forces for all exercises. The vacuum canisters provide the primary force while the flywheels are used to simulate the inertial component of the exercise as would be experienced on the ground. These are mechanical assemblies only. No sensors or cabling are installed.
Main Arm Assembly includes the wishbone arm and the lift bar components. Load cells have been installed in the lift bar struts and the associated cables have been attached.
Arm Base Assembly includes the load adjustment mechanism, interfaces for the Cylinder / Flywheel Assembly, Main Arm Assembly, Cable Pulley Assembly, and the Frame / Platform Assembly. Two load cells, one rotational sensor, and associated cables are installed. The two load cells measure the reactive loads during cable-based exercises.
Belt / Pulley Assembly provides the capability to perform cable-based exercises. It interfaces the exercise rope to the Arm Base Assembly to provide load for the exercises. This is a mechanical assembly only. No sensors or wiring are installed.
Exercise Bench Assembly is an accessory that mounts to the platform and provides a surface for performing shoulder presses, bench presses, and other seated or lying exercises. It is folded up and stowed when not in use.
Heel Block Assembly is an accessory that mounts to the platform and allows the capability for performing heel-raise exercises. It is removed and stowed when not in use.
The ARED will operate in the following modes:
Resistance is provided by the movement of pistons within the vacuum of the cylinders. The piston rods are attached to an arm base assembly, which acts as a lever arm when the main arm assembly is moved.
In addition, ARED is fitted with a second resistance mechanism. This mechanism is a flywheel assembly that rotates as the arm base assembly is moved. This function provides an inertial load which, when moved, mimics the inertial load of a free-weight.
Resistive load can be changed by turning a load adjustment handle that will move the attachment point of the piston rods, thereby changing the length of the lever arm. The lever is able to provide loads ranging from 0 to 600+ pounds. ARED can be configured to provide exercises using the lift bar or the exercise cable. Using the cable, the loads are limited to a maximum of 150 pounds.
A major feature of ARED is the instrumentation system. This system includes triaxial force sensors located in the exercise platform that are able to record force in three dimensions. In addition, load sensors in the main lift arm and the arm base assembly measure unidirectional forces. The arm base assembly also has rotational sensors that record the range of motion of the arm.
In flight, force data will be sent to the ARED Instrumentation Box (AIB) and recorded using the ARED tablet personal computer (PC). This computer will have a user interface that allows exercise prescriptions to be sent from the Mission Control Center (MCC) at JSC to the ARED tablet PC. The exercise prescription will be automatically loaded into an individual crewmember profile. The profile will be accessed during exercise sessions. During exercise, the load and number of repetitions will be simultaneously recorded and displayed on the tablet PC. On ISS, the recorded data will be automatically downloaded to an on-station server, and then down-linked to the MCC.
Currently planned maintenance of ARED includes periodic replacement of electrical cables at flex joints, brake cables and exercise cable, as well as an annual calibration and inspections. To the extent possible, maintenance activities will utilize existing standard ISS tools. Orbital replacement units (ORUs), access covers, caps, and structural parts that will be removed for on-orbit maintenance shall be designed with restraining and handling devices for temporary stowage by the crew in a microgravity environment.
The Advanced Resistive Exercise Device (ARED) was designed to address the limitations of the Interim Exercise Device (iRED) and serve as the next generation of in-flight resistance exercise hardware on the ISS. A study compared the musculoskeletal adaptations to 16 wk of resistance exercise training with the ARED to training with free weights (FW) in healthy, untrained, ambulatory men and women. It was proposed that 16 wk of training with the ARED or with FW would result in significant increases in muscle strength, muscle volume, lean tissue mass, vertical jump (VJ) height, and bone mineral density (BMD), and that FW would increase muscle strength, muscle volume, lean tissue mass, and BMD to a greater extent than ARED because of the differences in inertial characteristics of the ARED flywheels and FW. In ambulatory subjects, ARED training resulted in increases similar to those with FW training for all of the variables measured, the only exceptions being a greater rate of increase in squat (SQ) strength from midtraining to posttraining and a greater rate of increase in VJ height in the FW group. These device-dependent differences might relate to the inability of the ARED flywheels to mimic inertial characteristics of FW throughout the full range of resistances, or they could relate to differences in the biomechanics of exercise between the two devices. Given these findings, and considering the effectiveness of FW training at mitigating bed rest–induced deconditioning, we expect that ARED training will be a more effective countermeasure than iRED training against musculoskeletal deconditioning during spaceflight (Loehr et al., 2010).
Loehr JA, Sibonga J, Lee SM. C, Smith SM, English KL, Spiering BA, Hagan RD. Musculoskeletal adaptations to training with the advanced resistive exercise device. Medicine and Science in Sports and Exercise. 2011; 43(1): 146-156. PMID: 20473227.