Hypertrophic Aide by Limb Occlusion to Mitigate Muscle Atrophy in Spaceflight

Authors

Anaya Kashikar, Texas Woman's UniversityFollow
Erin Rocha, Texas Woman's UniversityFollow
Makiyah Brittmon, Texas Woman's UniversityFollow
Martha Word, Texas Woman's UniversityFollow
Clay Martin, Texas Woman's UniversityFollow
Matthew Pearson, Texas Woman's UniversityFollow
Josey Salazar, Texas Woman's UniversityFollow
Hannah Schnettler, Texas Woman's UniversityFollow
Karolyn Skoby, Texas Woman's UniversityFollow
Hunter Alvis, Texas Woman's UniversityFollow
Cayla Clark, Texas Woman's UniversityFollow
Baraquiel ReynaFollow
Brandon R. Rigby, Texas Woman's UniversityFollow

Abstract

Long-duration spaceflight can elicit increases in muscle disuse, thereby leading to a decrease in muscle mass. The consequences of these negative effects include decreases in muscle strength and mobility, and an increase in injury risk. The large muscle groups of the lower body are particularly susceptible to these adaptations. PURPOSE: To design, fabricate, and test a compact device that allows for blood flow restriction to be implemented during resistance training in spaceflight to promote muscle hypertrophy and aid in muscle recovery. METHODS: The custom device was originally designed in three-dimensional modeling software (Solidworks Premium, Waltham, MA). Components of the device included: a cuff and associated airbag, DC motors, microcontroller, motor board, and lithium-ion battery. To code the device, C++ and Arduino IDE software were used. The device was programmed to inflate to 140 mmHg (3 DC motors on motor pins 1-3), maintain inflation for 15 minutes, and deflate (1 DC motor on motor pin 4). Testing of hypertrophic aide by limb occlusion (HALO) was completed using a repeated measures design. Two young, untrained, female participants completed three visits: 1) baseline; 2) exercise without the HALO; and 3) exercise with the HALO. At baseline, a blood sample was collected from the antecubital space. Then, a 1-repetition maximum (1-RM) was determined for 5 key exercises: 1) back squat; 2) Romanian deadlift; 3) deadlift; 4) single-leg heel raise; and 5) single-leg knee extension. For at least 5 days prior to the baseline session, no structured exercise was performed. For the second visit, which occurred at least 2 days later, a blood sample was collected first. Then, the five exercises were performed, at an intensity of 70% 1-RM and a duration of 24 reps over 3 sets. For the third visit with the HALO, which occurred at least 5 days later, a blood sample was collected first. Then, the five exercises were again performed, at an intensity of 35% 1-RM and a duration of 75 reps over 4 sets. Serum concentrations of vascular endothelial growth factor (VEGF) were measured during each blood draw and later analyzed. RESULTS: Both participants completed all data collection procedures. When the airbag was deflated, the pressure read 0 mmHg. When inflated, the pressure in the airbag was approximately 140 mmHg. There was a slight delay in the time to reach the peak pressure due to the DC motor performance at that point. There was a 41.4% increase and 53.2% decrease, in VEGF concentrations from exercise without the HALO to exercise with the HALO in participants 1 and 2, respectively. CONCLUSION: The HALO device, which provides blood flow restriction during resistance exercise in spaceflight, may allow for enhanced training adaptations for astronauts. It is worth noting that inter- individual responses to exercise were evident with the study protocol.

Recommended Citation

Kashikar, Anaya; Rocha, Erin; Brittmon, Makiyah; Word, Martha; Martin, Clay; Pearson, Matthew; Salazar, Josey; Schnettler, Hannah; Skoby, Karolyn; Alvis, Hunter; Clark, Cayla; Reyna, Baraquiel; and Rigby, Brandon R. (2025) "Hypertrophic Aide by Limb Occlusion to Mitigate Muscle Atrophy in Spaceflight," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 17, Article 142.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss17/142