Publications by authors named "Alexandra Cobb"
Introduction: Nitrate supplementation in the form of beetroot juice (BRJ) ingestion has been shown to improve exercise tolerance during acute hypoxia, but its effect on exercise physiology remains unstudied during sustained terrestrial high altitude exposure. We hypothesized that performing exercise at high altitude would lower circulating nitrate and nitrite levels and that BRJ ingestion would reverse this phenomenon while concomitantly improving key determinants of aerobic exercise performance.
Methods: Twenty seven healthy volunteers (21 male) underwent a series of exercise tests at sea level (SL, London, 75 m) and again after 5-8 days at high altitude (HA, Capanna Regina Margherita or "Margherita Hut," 4,559 m).
Article Synopsis
- - Acute mountain sickness (AMS) affects many during high-altitude ascents, and this study aimed to explore how physiological factors relate to AMS occurrence during a trek to 5300 m.
- - Out of 332 participants, 73.5% experienced AMS, with 50.3% reporting moderate-to-severe symptoms; those with no prior exposure to altitudes over 5000 m were more at risk.
- - Key predictors for developing moderate-to-severe AMS included lower peripheral oxygen saturation (SpO) levels during exercise and no previous high-altitude experience, indicating these variables could help anticipate AMS risk in future treks.
Article Synopsis
- Native highlanders like Sherpa show amazing ability to tolerate low oxygen levels, potentially due to higher nitric oxide (NO) and better blood flow.
- The Xtreme Alps study tested if a nitrate-rich diet could enhance NO and blood flow in lowlanders at high altitudes by comparing it to a placebo.
- While dietary nitrate increased plasma nitrate and nitrite levels significantly, it did not improve blood flow in the participants, even under controlled oxygen conditions.
Article Synopsis
- The study investigates how attention is maintained on body shape and weight information in young women, particularly focusing on those with eating disorders versus those without.
- Participants included women aged 16-30 from three groups: eating disorder, high shape/weight-based self-worth, and low shape/weight-based self-worth.
- Results showed that women with high shape/weight-based self-worth avoided shape/weight stimuli more than those with low self-worth, while the eating disorder group had similar tendencies, suggesting different patterns of attention that could inform intervention strategies.
Objectives: Technology-based health interventions may provide a means to reach low-income perinatal women and improve outcomes for both mother and infant, yet little is known about technology access and interest among this population. This study explored interest, attitudes, and concerns regarding technology to deliver health information and interventions.
Methods: Between May and October 2014, a cross-sectional study of 161 low-income pregnant and/or postpartum mothers (up to 1 year) was conducted, assessing attitudes and behaviors regarding the current use of devices and receptivity to interventions delivered through devices.
Nitric oxide (NO) production plays a central role in conferring tolerance to hypoxia. Tibetan highlanders, successful high-altitude dwellers for millennia, have higher circulating nitrate and exhaled NO (E) levels than native lowlanders. Since nitrate itself can reduce the oxygen cost of exercise in normoxia it may confer additional benefits at high altitude.
View Article and Find Full Text PDFThe study of healthy human volunteers ascending to high altitude provides a robust model of the complex physiological interplay that emulates human adaptation to hypoxaemia in clinical conditions. Nitric oxide (NO) metabolism may play an important role in both adaptation to high altitude and response to hypoxaemia during critical illness at sea level. Circulating nitrate and nitrite concentrations can be augmented by dietary supplementation and this is associated with improved exercise performance and mitochondrial efficiency.
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