Abstract
The Gravity Loading Countermeasure Skinsuit (GLCS) has been devised to comfortably compress the body in a manner analogous to Earth’s gravity, via incrementally increasing z-axis fibre tensions from the shoulder to the feet. Previous work demonstrated heart rate-VO2 dissociation during sub-maximal exercise, leading to a reduction of predicted VO2max; this study sought to determine the effect of the GLCS upon actual VO2max.
Six subjects (♂4; 27.5±5.9 yrs; 173.6±9.7 cm; and 77.3±8.3 kg) who gave written informed consent to participate were fitted with a custom-fabricated GLCS. Lactate, heart rate, core temperature, and breath-by-breath respiratory parameters were recorded along with subjective comfort, body control and RPE during performance of a VO2Max test (Bruce ergometer protocol), when wearing either the GLCS, or loose fitting gym attire (GYM).
Actual VO2Max did not differ between GLCS and GYM, nor with previously predicted VO2Max values (obtained from the same subjects in a previous study). However, there was a significant interaction between VO2Max test type and attire, with predicted VO2Max being the greatest in the GLCS [F(1, 5) = 6.250; P=0.049]. No significant difference in wattage required to achieve VO2Max was found between attires; however, work product (wattage * time) was significantly lower in the GLCS (P=0.039). Additionally, no significant difference between the wattage achieved at the (lactate) anaerobic threshold (AT) and ventilatory breakpoint was observed in either attire. Heart rate, lactate, core temperature and all breath-by-breath parameters (VT, FR, TI/TTOT, VE, RER, EqO2, VCO2 and EqCO2) did not differ between attires at VO2Max. Movement discomfort was significantly greater in the GLCS vs. GYM, both at rest (p=0.05) and at VO2Max (P=0.024), when significantly lower body control was also observed (P=0.027).
Actual VO2max was similar in the GLCS vs. GYM, although less cycling work (and thus time) was achieved, suggestive that the GLCS may be a potential adjunct to aerobic exercise on Earth and in space.
Six subjects (♂4; 27.5±5.9 yrs; 173.6±9.7 cm; and 77.3±8.3 kg) who gave written informed consent to participate were fitted with a custom-fabricated GLCS. Lactate, heart rate, core temperature, and breath-by-breath respiratory parameters were recorded along with subjective comfort, body control and RPE during performance of a VO2Max test (Bruce ergometer protocol), when wearing either the GLCS, or loose fitting gym attire (GYM).
Actual VO2Max did not differ between GLCS and GYM, nor with previously predicted VO2Max values (obtained from the same subjects in a previous study). However, there was a significant interaction between VO2Max test type and attire, with predicted VO2Max being the greatest in the GLCS [F(1, 5) = 6.250; P=0.049]. No significant difference in wattage required to achieve VO2Max was found between attires; however, work product (wattage * time) was significantly lower in the GLCS (P=0.039). Additionally, no significant difference between the wattage achieved at the (lactate) anaerobic threshold (AT) and ventilatory breakpoint was observed in either attire. Heart rate, lactate, core temperature and all breath-by-breath parameters (VT, FR, TI/TTOT, VE, RER, EqO2, VCO2 and EqCO2) did not differ between attires at VO2Max. Movement discomfort was significantly greater in the GLCS vs. GYM, both at rest (p=0.05) and at VO2Max (P=0.024), when significantly lower body control was also observed (P=0.027).
Actual VO2max was similar in the GLCS vs. GYM, although less cycling work (and thus time) was achieved, suggestive that the GLCS may be a potential adjunct to aerobic exercise on Earth and in space.
| Original language | English |
|---|---|
| Article number | 466 |
| Pages (from-to) | 352 |
| Number of pages | 1 |
| Journal | Aviation Space and Environmental Medicine |
| Volume | 85 |
| Issue number | 3 |
| Publication status | Published - Mar 2014 |