Biomaterial Database

Oxygen uptake response during maximal cycling in hyperoxia, normoxia and hypoxia. 2001

J E Peltonen, and H O Tikkanen, and J J Ritola, and M Ahotupa, and H K Rusko

Unit for Sports and Exercise Medicine, Institute of Clinical Medicine, University of Helsinki, Finland. Juha.Peltonen@helsinki.fi

BACKGROUND Oxygen uptake (VO2) on-kinetics is decelerated in acute hypoxia and accelerated in hyperoxia in comparison with normoxia during submaximal exercise. However, the effects of fraction of oxygen in inspired air (FIO2) on VO2 kinetics during maximal exercise are unknown. OBJECTIVE The effects of FIO2 on VO2 on-kinetics during maximal exercise are similar to submaximal exercise. METHODS There were 11 endurance athletes who were studied during maximal 7-min cycle ergometer exercise in hyperoxia (FIO2 0.325), hypoxia (FIO2 0.166) and normoxia (FIO2 0.209). The individual VO2 data were fit to a curve by using a three exponential model. RESULTS In hypoxia, VO2 on-response amplitude during Phase 2 (approximately 20-100 s from the beginning of exercise) was lower (p < 0.05) when compared with hyperoxia; time constant of VO2 Phase 3 (beyond approximately 100 s after beginning of exercise) was shorter (p < 0.05) when compared with hyperoxia; and mean response time (MRT, O-63%) for VO2peak was shorter (p < 0.05) when compared with normoxia and hyperoxia. VO2peak was higher in hyperoxia (4.80 +/- 0.48 L x min(-1), p < 0.05) and lower in hypoxia (4.03 +/- 0.46 L x min(-1), p < 0.05) than in normoxia (4.36 +/- 0.44 L x min(-1)). CONCLUSIONS Moderate hypoxia or hyperoxia do not affect VO2 time constants at the onset of maximal exercise. However, MRT for VO2peak is shortened in hypoxia. It is suggested that the differences in VO2peak and power output during the latter half of the test and the point that FIO2 was modified only moderately might explain most of the discrepancy with the previous studies.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D005080	Exercise Test	Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.	Arm Ergometry Test,Bicycle Ergometry Test,Cardiopulmonary Exercise Testing,Exercise Testing,Step Test,Stress Test,Treadmill Test,Cardiopulmonary Exercise Test,EuroFit Tests,Eurofit Test Battery,European Fitness Testing Battery,Fitness Testing,Physical Fitness Testing,Arm Ergometry Tests,Bicycle Ergometry Tests,Cardiopulmonary Exercise Tests,Ergometry Test, Arm,Ergometry Test, Bicycle,Ergometry Tests, Arm,Ergometry Tests, Bicycle,EuroFit Test,Eurofit Test Batteries,Exercise Test, Cardiopulmonary,Exercise Testing, Cardiopulmonary,Exercise Tests,Exercise Tests, Cardiopulmonary,Fitness Testing, Physical,Fitness Testings,Step Tests,Stress Tests,Test Battery, Eurofit,Test, Arm Ergometry,Test, Bicycle Ergometry,Test, Cardiopulmonary Exercise,Test, EuroFit,Test, Exercise,Test, Step,Test, Stress,Test, Treadmill,Testing, Cardiopulmonary Exercise,Testing, Exercise,Testing, Fitness,Testing, Physical Fitness,Tests, Arm Ergometry,Tests, Bicycle Ergometry,Tests, Cardiopulmonary Exercise,Tests, EuroFit,Tests, Exercise,Tests, Step,Tests, Stress,Tests, Treadmill,Treadmill Tests
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000860	Hypoxia	Sub-optimal OXYGEN levels in the ambient air of living organisms.	Anoxia,Oxygen Deficiency,Anoxemia,Deficiency, Oxygen,Hypoxemia,Deficiencies, Oxygen,Oxygen Deficiencies
D015444	Exercise	Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.	Aerobic Exercise,Exercise, Aerobic,Exercise, Isometric,Exercise, Physical,Isometric Exercise,Physical Activity,Acute Exercise,Exercise Training,Activities, Physical,Activity, Physical,Acute Exercises,Aerobic Exercises,Exercise Trainings,Exercise, Acute,Exercises,Exercises, Acute,Exercises, Aerobic,Exercises, Isometric,Exercises, Physical,Isometric Exercises,Physical Activities,Physical Exercise,Physical Exercises,Training, Exercise,Trainings, Exercise
D018384	Oxidative Stress	A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).	Anti-oxidative Stress,Antioxidative Stress,DNA Oxidative Damage,Nitro-Oxidative Stress,Oxidative Cleavage,Oxidative DNA Damage,Oxidative Damage,Oxidative Injury,Oxidative Nitrative Stress,Oxidative Stress Injury,Oxidative and Nitrosative Stress,Stress, Oxidative,Anti oxidative Stress,Anti-oxidative Stresses,Antioxidative Stresses,Cleavage, Oxidative,DNA Damage, Oxidative,DNA Oxidative Damages,Damage, DNA Oxidative,Damage, Oxidative,Damage, Oxidative DNA,Injury, Oxidative,Injury, Oxidative Stress,Nitrative Stress, Oxidative,Nitro Oxidative Stress,Nitro-Oxidative Stresses,Oxidative Cleavages,Oxidative DNA Damages,Oxidative Damage, DNA,Oxidative Damages,Oxidative Injuries,Oxidative Nitrative Stresses,Oxidative Stress Injuries,Oxidative Stresses,Stress Injury, Oxidative,Stress, Anti-oxidative,Stress, Antioxidative,Stress, Nitro-Oxidative,Stress, Oxidative Nitrative,Stresses, Nitro-Oxidative