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Journal of Sports Science & Medicine Sep 2022To propose a new Cardiopulmonary Exercise Test with Elastic Resistance (CPxEL) and compare the physiological responses to conventional cardiopulmonary exercise test...
To propose a new Cardiopulmonary Exercise Test with Elastic Resistance (CPxEL) and compare the physiological responses to conventional cardiopulmonary exercise test (CPx) performed on a treadmill. In addition, we tested the reproducibility of the CPxEL. Twenty-four physically active participants completed the CPx (first session) and CPxEL twice (second and third sessions) interspersed by seven days. A treadmill protocol with increments of 1km·h every minute until exhaustion was used in CPx. The CPxEL consisted of performing alternating steps back-and-forth against an elastic resistance attached to a belt and an incremental protocol with 1 stage (S) per minute following a cadence of 200 bpm controlled by a metronome in an 8-stage rubber mat. First analysis: first ventilatory threshold (VT1) occurred at 69.7% and 75.3% of maximal heart rate (HR) and 53.5% and 65.7% of maximal oxygen consumption (V̇O). Second VT (VT2) occurred at 93.3% and 96.8% of the HR and 87.0% and 96.9% of V̇O for CPx and CPxEL, respectively. At exhaustion, V̇O, perceived exertion (BORG-CR10 and OMNI-RES EB), and test duration presented lower values for CPxEL (P < 0.05). Second analysis: VT1 occurred at warm-up (S0) (P = 0.731), VT2 occurred at S5 (P = 0.912), and the exhaustion occurred at S6 and S7 (P = 0.271) for CPxEL and retest, respectively. The intraclass correlation coefficient (ICC) for V̇O was 0.921 and for HR was 0.930. The CPxEL has good test-retest reproducibility and represents a possible and interesting add-on to determine maximal oxygen consumption, maximal heart rate, and second ventilatory threshold without using traditional ergometers.
Topics: Exercise Test; Heart Rate; Humans; Oxygen Consumption; Reproducibility of Results; Rubber
PubMed: 36157388
DOI: 10.52082/jssm.2022.426 -
Exercise and Sport Sciences Reviews Jan 2018An imbalance in oxygen delivery to demand in solid tumors results in local areas of hypoxia leading to poor prognosis for the patient. We hypothesize that aerobic... (Review)
Review
An imbalance in oxygen delivery to demand in solid tumors results in local areas of hypoxia leading to poor prognosis for the patient. We hypothesize that aerobic exercise increases tumor blood flow, recruits previously nonperfused tumor blood vessels, and thereby augments blood-tumor O2 transport and diminishes tumor hypoxia. When combined with conventional anticancer treatments, aerobic exercise can significantly improve the outcomes for several types of cancers.
Topics: Exercise; Humans; Hypoxia; Neoplasms; Oxygen Consumption; Tumor Microenvironment
PubMed: 29166299
DOI: 10.1249/JES.0000000000000137 -
Trends in Endocrinology and Metabolism:... Jul 2016A recent study has highlighted the relationship between mitochondrial ATP generation and protection against organ injury following ischaemia-reperfusion injury in the... (Review)
Review
A recent study has highlighted the relationship between mitochondrial ATP generation and protection against organ injury following ischaemia-reperfusion injury in the kidney. Kidneys are fuel-hungry organs and only second to the heart in mitochondrial number and oxygen consumption. This article speculates on why this might be so.
Topics: Animals; Humans; Mitochondria; Myocardium; Niacinamide; Oxidative Phosphorylation; Oxidative Stress; Oxygen Consumption; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
PubMed: 27215468
DOI: 10.1016/j.tem.2016.05.002 -
International Journal of Sports... Mar 2022Accumulated time at a high percentage of peak oxygen consumption (VO2peak) is important for improving performance in endurance athletes. The present study compared the...
PURPOSE
Accumulated time at a high percentage of peak oxygen consumption (VO2peak) is important for improving performance in endurance athletes. The present study compared the acute physiological and perceived effects of performing high-intensity intervals with roller ski double poling containing work intervals with (1) fast start followed by decreasing speed (DEC), (2) systematic variation in exercise intensity (VAR), and (3) constant speed (CON).
METHODS
Ten well-trained cross-country skiers (double-poling VO2peak 69.6 [3.5] mL·min-1·kg-1) performed speed- and duration-matched DEC, VAR, and CON on 3 separate days in a randomized order (5 × 5-min work intervals and 3-min recovery).
RESULTS
DEC and VAR led to longer time ≥90% VO2peak (P = .016 and P = .033, respectively) and higher mean %VO2peak (P = .036, and P = .009) compared with CON, with no differences between DEC and VAR (P = .930 and P = .759, respectively). VAR, DEC, and CON led to similar time ≥90% of peak heart rate (HRpeak), mean HR, mean breathing frequency, mean ventilation, and mean blood lactate concentration ([La-]). Furthermore, no differences between sessions were observed for perceptual responses, such as mean rate of perceived exertion, session rate of perceived exertion or pain score (all Ps > .147).
CONCLUSIONS
In well-trained XC skiers, DEC and VAR led to longer time ≥90% of VO2peak compared with CON, without excessive perceptual effort, indicating that these intervals can be a good alternative for accumulating more time at a high percentage of VO2peak and at the same time mimicking the pronounced variation in exercise intensities experienced during XC-skiing competitions.
Topics: Exercise Test; Humans; Lactic Acid; Oxygen; Oxygen Consumption; Skiing
PubMed: 34814113
DOI: 10.1123/ijspp.2021-0226 -
Animal Reproduction Science Jan 2016The aim of this study was to assess the viability of vitrified-warmed in vivo-derived pig embryos after measuring the oxygen consumption rate. Six days after artificial...
The aim of this study was to assess the viability of vitrified-warmed in vivo-derived pig embryos after measuring the oxygen consumption rate. Six days after artificial insemination, blastocysts were collected from gilts and vitrified by the micro volume air cooling method. The oxygen consumption rate was measured in 60 vitrified-warmed embryos, which were then cultured for 48h to assess the viability. The survival (re-expansion) rate of embryos after warming was 85.0%. The average oxygen consumption rate of embryos immediately after warming was greater in embryos which could re-expand during subsequent culture (F=0.75±0.04) than that in those which failed to re-expand (F=0.33±0.05). Moreover, the oxygen consumption rate of vitrified-warmed embryos was greater in the hatched (F=0.88±0.06) than that in the not-hatched group (F=0.53±0.04). When the oxygen consumption rate of the vitrified-warmed embryos and the numbers of viable and dead cells in embryos were determined, there was a positive correlation between the oxygen consumption rate and the number of live cells (P<0.01, r=0.538). A total of 29 vitrified embryos after warming and measuring the oxygen consumption rate were surgically transferred into uterine horns of two recipients. Both of the recipients become pregnant and farrowed 12 healthy piglets. These results demonstrate that the oxygen consumption rate of vitrified-warmed pig embryos can be related to the number of live cells and that the measurement of oxygen consumption of embryos after cryopreservation may be useful for estimating embryo survivability.
Topics: Animals; Embryo Culture Techniques; Embryo Transfer; Female; Oxygen Consumption; Pregnancy; Pregnancy Rate; Swine; Tissue and Organ Harvesting; Vitrification
PubMed: 26642748
DOI: 10.1016/j.anireprosci.2015.11.008 -
Physiological Genomics Oct 2023Low cardiorespiratory fitness, measured as maximal oxygen uptake (V̇o), is associated with all-cause mortality and disease-specific morbidity and mortality and is...
Low cardiorespiratory fitness, measured as maximal oxygen uptake (V̇o), is associated with all-cause mortality and disease-specific morbidity and mortality and is estimated to have a large genetic component (∼60%). However, the underlying mechanisms explaining the associations are not known, and no association study has assessed shared genetics between directly measured V̇o and disease. We believe that identifying the mechanisms explaining how low V̇o is related to increased disease risk can contribute to prevention and therapy. We used a phenome-wide association study approach to test for shared genetics. A total of 64,479 participants from the Trøndelag Health Study (HUNT) were included. Genetic variants previously linked to V̇o were tested for association with diseases related to the cardiovascular system, diabetes, dementia, mental disorders, and cancer as well as clinical measurements and biomarkers from HUNT. In the total population, three single-nucleotide polymorphisms (SNPs) in and near the follicle-stimulating hormone receptor gene () were found to be associated (false discovery rate < 0.05) with serum creatinine levels and one intronic SNP in the Rap-associating DIL domain gene () with diabetes type 1 with neurological manifestations. In males, four intronic SNPs in the PBX/knotted homeobox 2 gene () were found to be associated with endocarditis. None of the association tests in the female population reached overall statistical significance; the associations with the lowest values included other cardiac conduction disorders, subdural hemorrhage, and myocarditis. The results might suggest shared genetics between V̇o and disease. However, further effort should be put into investigating the potential shared genetics between inborn V̇o and disease in larger cohorts to increase statistical power. To our knowledge, this is the first genetic association study exploring how genes linked to cardiorespiratory fitness (CRF) relate to disease risk. By investigating shared genetics, we found indications that genetic variants linked to directly measured CRF also affect the level of blood creatinine, risk of diabetes, and endocarditis. Less certain findings showed that genetic variants of high CRF might cause lower body mass index, healthier HDL cholesterol, and lower resting heart rate.
Topics: Male; Humans; Female; Genetic Association Studies; Oxygen; Oxygen Consumption
PubMed: 37575066
DOI: 10.1152/physiolgenomics.00026.2023 -
Journal of Cardiothoracic and Vascular... Jul 2019
Review
Topics: Cardiac Surgical Procedures; Cardiopulmonary Bypass; Humans; Hyperoxia; Oxygen; Oxygen Consumption; Oxygen Inhalation Therapy; Perioperative Care; Postoperative Complications
PubMed: 29567040
DOI: 10.1053/j.jvca.2018.02.015 -
Cerebrovascular Diseases (Basel,... 2023The peak oxygen consumption (V.O2peak) and blood hemoglobin concentration [Hb] are lower in stroke patients than in age-matched healthy subjects. The ability of skeletal...
BACKGROUND
The peak oxygen consumption (V.O2peak) and blood hemoglobin concentration [Hb] are lower in stroke patients than in age-matched healthy subjects. The ability of skeletal muscles to extract oxygen is diminished after stroke. We hypothesized that the oxygen extraction capacity of skeletal muscles in stroke patients depends on [Hb]. To test the hypothesis, we determined the relationship between V.O2peak and total hemoglobin mass (tHb-mass) in stroke patients.
METHODS
The subjects were 19 stroke patients (age: 74 ± 2, mean ± SD, 10 males) and 11 age-matched normal subjects (age 76 ± 3, 6 males). Plasma volume (PV) and V.O2peak were measured on the same day. PV was measured using Evans Blue dye dilution method. Blood volume (BV) was calculated from PV and hematocrit, while tHb-mass was estimated from BV and [Hb]. Each subject underwent cardiopulmonary exercise test on a bicycle ergometer using a V.O2peak respiratory gas analyzer.
RESULTS
There were no differences in age, height, and weight between the two groups. V.O2peak was lower in stroke patients than in the control. BV and tHb mass were not significantly different between the two groups, but [Hb] was significantly lower in stroke patients. In stroke patients, V.O2peak correlated significantly with tHb-mass (r = 0.497, p < 0.05), but not with BV.
CONCLUSION
Our results suggested that low [Hb] seems to contribute to V.O2peak in stroke patients. The significant correlation between tHb-mass and V.O2peak suggested that treatment to improve [Hb] can potentially improve V.O2peak in stroke patients.
Topics: Aged; Humans; Male; Exercise Test; Hemoglobins; Oxygen; Oxygen Consumption; Stroke; Female
PubMed: 35917807
DOI: 10.1159/000525597 -
The Journal of Sports Medicine and... Jan 2024Freediving is defined as an activity where athletes repetitively dive and are exposed to long efforts with limited oxygen consumption. Therefore, anaerobic features are...
BACKGROUND
Freediving is defined as an activity where athletes repetitively dive and are exposed to long efforts with limited oxygen consumption. Therefore, anaerobic features are expected to be an important facet of diving performance. This study aimed to investigate differences in anaerobic capacity and local muscle oxygenation in spearfisherman and freedivers.
METHODS
The sample of participants included 17 male athletes (nine freedivers, and eight spearfishermen), with an average age of 37.0±8.8 years, training experience of 10.6±9.5 years, body mass of 82.5±9.5 kg and height of 184.2±5.7 cm. Anthropometric characteristics included: body mass, body height, seated height, and body fat percentage. Wingate anaerobic test was conducted, during which local muscle oxygenation was measured with a NIRS device (Moxy monitor). Wingate power outputs were measured (peak power [W/kg] and average power [W/kg]), together with muscle oxygenation variables (baseline oxygen saturation [%], desaturation slope [%/s], minimum oxygen saturation [%], half time recovery [s], and maximum oxygen saturation [%]).
RESULTS
The differences were not obtained between freedivers and spearfisherman in power outputs (peak power (9.24±2.08 spearfisherman; 10.68±1.04 freedivers; P=0.14); average power (6.85±0.95 spearfisherman; 7.44±0.60 freedivers; P=0.15) and muscle oxygenation parameters. However, analysis of effect size showed a moderate effect in training experience (0.71), PP (0.89), AP (0.75), Desat slope mVLR (0.66), half time recovery mVLR (0.90).
CONCLUSIONS
The non-existence of differences between freedivers and spearfishermen indicates similar training adaptations to the anaerobic demands. However, the results show relatively low anaerobic capacities of our divers that could serve as an incentive for the further development of these mechanisms.
Topics: Humans; Male; Adult; Middle Aged; Anaerobiosis; Oxygen Saturation; Muscles; Oxygen Consumption; Diving; Exercise Test; Anaerobic Threshold
PubMed: 37902796
DOI: 10.23736/S0022-4707.23.15185-1 -
Comprehensive Physiology Mar 2023Although it is intuitive that large mammals need more food than smaller ones, it is not so obvious that, relative to their body mass, larger mammals consume less than...
Although it is intuitive that large mammals need more food than smaller ones, it is not so obvious that, relative to their body mass, larger mammals consume less than smaller ones. In fact, on a per kg basis, the resting metabolic rate of a mouse is some 50 times higher than that of an elephant. The fact that metabolism could not be proportional to the mass of the animal was suggested by Sarrus and Rameaux in 1838. The first indication that oxygen consumption (or other indices of metabolic rate, Y) related to the animal body mass (M) according to an exponential of the type Y = a · M , where b was about 0.75, was presented by Max Kleiber in 1932. Two years later Samuel Brody had collected sufficient data to construct the first "mouse-to-elephant" metabolic curve. The physiological basis of the relationship has been the object of many hypotheses, often accompanied by a great deal of controversy. This historical essay traces the origin of the mouse-to-elephant metabolic function, recalling the earliest concepts of metabolism and its measurements to understand the body size dependency, which is still one of the most elusive phenomena in comparative physiology. A brief look at the metabolic scaling of nonmammalian organisms will be included to frame the mouse-to-elephant curve into a broader context and to introduce some interesting interpretations of the mammalian function. © 2023 American Physiological Society. Compr Physiol 13:4513-4558, 2023.
Topics: Animals; Mice; Elephants; Body Size; Mammals; Basal Metabolism; Oxygen Consumption
PubMed: 36994766
DOI: 10.1002/cphy.c220003