ABSTRACT
Oxygen uptake (VË O2) was measured during a non-exhaustive high-intensity intermittent cross-exercise (HIICE) protocol consisting of four alternating bouts of 20 âs running (R) and three bouts of bicycle exercise (BE) at â¼160% and â¼170% maximal oxygen uptake (VË O2max), respectively, with 10 âs between-bout rests (sequence R-BE-R-BE-R-BE-R). The VË O2 during the last BE ([52.2 â± â5.0] mL·kg-1·min-1) was significantly higher than the VË O2max of the BE ([48.0 â± â5.4] mL·kg-1·min-1, n â= â30) and similar to that of running. For clarifying the underlying mechanisms, a corresponding HIICE-protocol with BE and arm cranking ergometer exercise (AC) was used (sequence AC-AC-BE-AC-BE-AC-AC-BE). In some experiments, thigh blood flow was occluded by a cuff around the upper thigh. Without occlusion, the VË O2 during the AC ([39.2 â± â7.1] mL·kg-1·min-1 [6th bout]) was significantly higher than the VË O2max of AC ([30.2 â± â4.4] mL·kg-1·min-1, n â= â7). With occlusion, the corresponding VË O2 ([29.8 â± â3.9] mL·kg-1·min-1) was reduced to that of the VË O2max of AC and significantly less than the VË O2 without occlusion. These findings suggest that during the last bouts of HIICE may exceed the of the specific exercise, probably because it is a summation of the VË O2 for the ongoing exercise plus excess post-oxygen consumption (EPOC) produced by the previous exercise with a higher VË O2max.
ABSTRACT
Cardiopulmonary exercise testing (CPET) is an important tool to measure the cardiopulmonary fitness of an individual and has been widely used in athletic, clinical and research settings. Most CPET focus on analyzing physiological responses during exercise. We contend that the post-CPET recovery physiological responses offer further diagnostic and prognostic information about the health of the cardiopulmonary and metabolic systems, especially when testing apparently healthy middle-aged and older adults. However, there are limited studies that investigate physiological responses during the post-CPET recovery, and even less so in middle-aged and older adults. Therefore, this current review is aimed at discussing the contribution of post-CPET recovery parameters to cardiopulmonary health and their potential applications in aging populations. In addition to the existing methods, we propose to examine the aerobic and anaerobic recovery threshold post-CPET as novel potential diagnostic and/or prognostic tools.
ABSTRACT
To investigate the effects of short-term fasting on spontaneous activity and excess post-exercise oxygen consumption (EPOC) in sit-and-wait carnivorous southern catfish (Silurus meridionalis), active carnivorous black carp (Mylopharyngodon piceus), active herbivorous grass carp (Ctenopharyngodon idellus) and active filter-feeding silver carp (Hypophthalmichthys molitrix), each species was divided into a control group and a fasting group (deprived of food for 14â days). Both groups were maintained at 25°C and, at the end of the experimental period, the total movement distance (TMD), percent time spent moving (PTM), ventilation frequency (Vf), pre-exercise oxygen consumption (M(â¢)O2) and EPOC response of the experimental fish were measured. The TMD and PTM obtained for the control group of southern catfish were lower than those found for the control groups of the three active species. Short-term fasting resulted in decreases in the TMD and PTM of the southern catfish and black carp and increases in the TMD of grass carp and silver carp. The Vf of southern catfish was significantly higher than those of grass carp and silver carp, whereas the latter was also significantly higher than that of black carp. Short-term fasting resulted in significant increases in the Vf and decreases in the pre-exercise M(â¢)O2 of southern catfish and silver carp. Southern catfish and black carp exhibited lower peak post-exercise M(â¢)O2 and recovery rates, and relatively higher EPOC magnitudes than grass carp and silver carp. Short-term fasting exerted no significant effects on the peak post-exercise M(â¢)O2, but resulted in relatively higher EPOC magnitudes in the four fish species. These results suggest that (1) different fish species exhibit significantly different levels of spontaneous activity and post-exercise M(â¢)O2 profiles with different characteristics and that (2) short-term fasting exerts different effects on the level of spontaneous activity in four fish species with different foraging strategies.
Subject(s)
Fasting/metabolism , Fishes/metabolism , Oxygen Consumption , Physical Conditioning, Animal , Animals , Behavior, Animal , Body Weights and Measures , Energy Metabolism , Time FactorsABSTRACT
The purpose of this study was to investigate the acute effects on excess post-exercise oxygen consumption (EPOC) of low intensity and slow-movement repetitive resistance exercise in moderately trained young men. Seven healthy trained young men (age=22±3 yr ; height=172.5±4.0 cm ; weight=69.5±8.3 kg ; VO<sub>2</sub>max=47.3±6.0 ml/kg/min) performed the following three exercise patterns on separate days : 1) high-intensity (80% one-repetition maximum : 1RM) and regular-movement repetitive exercise (1 second each of concentric and eccentric action, termed high and regular exercise (HRE) ; 2) low-intensity (50%1RM), regular-movement repetitive exercise (same movement speed as for HRE but termed low and regular exercise (LRE); and 3) low-intensity (50%1RM), slow-movement repetitive exercise (4 sec each of concentric and eccentric action, termed low and slow exercise (LSE). These three exercise patterns consisted of three sets of four exercises performed to maximum repetition. All subjects completed the three exercise sessions in a randomized and counterbalanced fashion. Oxygen consumption (VO<sub>2</sub>) and heart rate (HR) were continuously monitored during the exercise sessions and for 90 min afterwards. EPOC over 90 min was thus observed after completing the three exercise patterns. However, there were no significant differences in EPOC among the three exercise patterns. The results of this study suggest that low-intensity and slow-movement repetitive resistance exercise with maintaining muscular tension (LSE) is likely to increase EPOC to the same extent as HRE and LRE exercise patterns.
