title: Oxygen Delivery and Muscle Deoxygenation during Continuous, Long- and Short-Interval Exercise.
abstract: This study compared the O2 delivery (a central determinant of VO2) and muscle deoxygenation (reflecting a peripheral determinant of VO2) during intense continuous, long-interval, and short-interval exercise protocols. Twelve young men completed the 3 protocols with equal overall effort. Simultaneous and continuous recordings of central hemodynamics, muscle oxygenation/deoxygenation and VO2 were performed. Peak responses for stroke volume and peripheral resistance did not differ among protocols, whereas peak cardiac output and VO2 were higher in long-interval vs. continuous and short-interval protocols with inactive rest phases (p<0.05). The average responses for all central parameters were higher in continuous and long-interval vs. short-interval exercise (p<0.05); average VO2 and exercise-time above 80% VO2max were also higher in continuous and long-interval vs. short-interval protocol (p<0.05). Muscle de-oxygenation (↑Δdeoxyhemoglobin,↓Δoxyhemoglobin, ↓muscle O2-saturation), as well as the mismatch of O2 delivery and utilization (Δdeoxyhemoglobin/VO2) were remarkably alike among protocols. In conclusion, all 3 protocols resulted in a great activation of central and peripheral determinants of VO2. When performed with equal overall effort, the intense continuous and interval modalities reveal similarities in muscle O2-utilization response, but differences in central hemodynamic and VO2 responses. Intense continuous and long-interval protocols exert a more commanding role on the cardiovascular system and VO2 response compared to short-interval exercise with inactive rest phases.
authors.affiliation: Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Zafeiridis
authors.affiliation: Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Kounoupis
authors.affiliation: Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece.
authors.forename: K
authors.initials: K
authors.lastname: Dipla
authors.affiliation: Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Kyparos
authors.affiliation: Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece.
authors.forename: M G
authors.initials: MG
authors.lastname: Nikolaidis
authors.affiliation: Physical Education and Sport Science, Democritus University of Thrace, Komotini, Greece.
authors.forename: I
authors.initials: I
authors.lastname: Smilios
authors.affiliation: Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece.
authors.forename: I S
authors.initials: IS
authors.lastname: Vrabas
mesh_terms: D015444:Exercise / Q000502:physiology*; D006439:Hemodynamics; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010108:Oxyhemoglobins / Q000378:metabolism; D010807:Physical Endurance / Q000502:physiology; D012123:Pulmonary Ventilation; D013997:Time Factors; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen