Ergonomic Considerations of Fin Size for Working Divers

1982 ◽  
Vol 26 (6) ◽  
pp. 525-529 ◽  
Author(s):  
I. B. Mekjavic ◽  
P. A. Rowe ◽  
J. B. Morrison
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Cardiovascular System ◽  
Surface Area ◽  
Minute Ventilation ◽  
Metabolic Cost ◽  
Breathing Frequency ◽  
Work Period ◽  
Ventilatory Volume

Four divers conducted two identical work protocols, consisting of swimming against a graded resistance on an underwater ergometer at a depth of ten feet. In one protocol the divers used fins each having a surface area of 540 cm2 and in the second protocol they used fins whose surface area was 940 cm2. Oxygen consumption, heart rate, ventilation, breathing frequency and kick rate were monitored throughout the twenty minute work period. The 540 cm2 fins demanded a siqnificantly higher metabolic rate than the 940 cm2 fins (50.85 ± 1.54 compared to 46.99 ± 1.52 ml.min.-1.kg-1). The smaller fins also elicited higher heart rates (171.8 ± 4.3 min.-1) than the larger fins (142.5 ± 8.7 min.-1) and induced a higher kicking frequency than was required with the larger fins (43 ± 4 min.-1 and 32 ± 1 min.-1 respectively). Ventilatory volume at the end of the final workload was 128.6 ± 7 1/min. with small fins and 111.1 ± 6.5 1/min. with large fins. These data suggest that the larger fins are more economical in terms of minute ventilation and metabolic cost and are less demanding on the cardiovascular system. Subjectively, the larger fins were perceived as less fatiguing than the smaller fins.

Respiratory Metabolism During Pregnancy in the Guinea Pig

1957 ◽  
Vol 190 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Richard M. Hoar ◽  
William C. Young
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Guinea Pig ◽  
Metabolic Rate ◽  
Adrenal Cortex ◽  
Guinea Pigs ◽  
Sharp Decrease ◽  
Zona Fasciculata ◽  
Respiratory Metabolism ◽  
Morphological Differences

Oxygen consumption and heart rate during pregnancy were measured in untreated, thyroxin-injected and thyroidectomized guinea pigs given I131. From impregnation until parturition, oxygen consumption increased 7.9% in untreated females. The increase continued until 5 days postpartum when a sharp decrease occurred. The increase is not accounted for by growth of the fetal mass. Comparable increases occurred in thyroxin-injected (16.2%) and thyroidectomized (11.9%) females, although the levels throughout were higher and lower, respectively, than in intact females. Heart rate did not increase. On the contrary, statistically significant decreases occurred in the untreated and thyroxin-injected females. Although the mechanism associated with the increased metabolic rate is not known, the possibility of thyroid participation would seem to be excluded. Involvement of the adrenal cortex is suggested by morphological differences in the cells of the zona fasciculata in pregnant and nonpregnant females and by evidence cited from other studies.

Respiratory responses to air-exposure in the southern rock lobster, Jasus edwardsii (Hutton) (Decapoda:Palinuridae)

1997 ◽  
Vol 48 (8) ◽  
pp. 889 ◽  
Author(s):  
H. Harry Taylor ◽  
Francesca M. Waldron
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Base Excess ◽  
Respiratory Acidosis ◽  
Metabolic Cost ◽  
Excess Oxygen ◽  
Air Exposure ◽  
Water Oxygen ◽  
Jasus Edwardsii ◽  
Resting Metabolism

Air-exposure of settled Jasus edwardsii at 17˚C initially halved oxygen consumption, doubled ventilation frequency and reduced heart rate. During 8 h emersion, oxygen uptake partially recovered, ventilation remained elevated and heart rate was restored. Haemolymph PCO2 increased fourfold, despite the hyperventilation. Branchial gas exchange, initially impaired in air, may improve as the gills drain. Partial anaerobiosis was indicated by elevation of haemolymph [lactate-] to 4.2 mmol L-1. Although haemolymph pH decreased ~0.3 units over 8 h, a base excess compensated all of the metabolic and part of the respiratory acidosis. On return to water, oxygen consumption initially increased to >2.5 times pre-emersion rates while ventilation and heart rates increased further. Most respiratory variables returned to pre-emersion levels within 8 h of re- immersion, but oxygen consumption and heart rate remained elevated for 24 h. The excess oxygen consumption over resting rate during 24 h recovery in water indicated a metabolic cost of 8 h emersion equivalent to 10 h resting metabolism in water. These responses contrast with better acid–base compensation previously reported for undisturbed Homarus gammarus in air and worse tolerance of air-exposure by Panulirus argus

scholarly journals Comparison of Cardiorespiratory and Metabolic Responses Between Kettlebell Half Marathon and Treadmill Running at the Same Average Oxygen Consumption: A Case Study

2020 ◽  
Author(s):  
Davide Greco ◽  
Luca Calanni ◽  
Giuseppe Cerullo ◽  
Massimo Negro ◽  
Giuseppe D’Antona
Keyword(s):  
Blood Pressure ◽  
Oxygen Consumption ◽  
Respiratory Exchange Ratio ◽  
Minute Ventilation ◽  
Treadmill Running ◽  
Metabolic Responses ◽  
Breathing Frequency ◽  
Exercise Routine ◽  
The Subject

Abstract Purposes In kettlebell sport (KS) half marathon, the lift of the kettlebell is required for the highest number of repetitions in 30 min. No data are available on cardiorespiratory and metabolic responses during this exercise routine. The aim of the study was to evaluate cardiopulmonary and metabolic responses to KS half marathon compared to 30 min treadmill running, chosen as a reference paradigm of aerobic exercise, at the same average oxygen consumption (VO2). Methods A male elite KS athlete was enrolled in two trials separated by 7 days of rest. In the first trial, one-hand long-cycle KS exercise with a 1/3 body weight kettlebell was performed for 30 min (kettlebell half marathon, KT); in the second trial, 30 min treadmill running (TR) was performed at the same average VO2 measured in the first trial (speed 9–10 km/h at 1° uphill inclination). Metabolic and cardiopulmonary assessments [respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE)], blood lactate (BL) kinetics, heart rate (HR), and blood pressure (BP) were measured in both experimental sessions. Results The average VO2 was 33.3 mL/min/kg in KT and 30.6 mL/min/kg in TR. The subject achieved RERpeak 1.17, RERmean 0.98, HRpeak 172 bpm (94% HRmax), HRmean 86% of HRmax, BPpeak 220/100 mmHg in KT, BLpeak 7.2 mmol/L (during trial) in KT and RERpeak 1.13, RERmean 0.89, HRpeak 142 bpm (78% HRmax), HRmean 70% of HRmax, BPpeak 160/80 mmHg, BLpeak 3.5 mmol/L (4 min after trial) mmol/L in TR. Conclusion Data indicate that a KS half marathon determines much higher cardiopulmonary and metabolic responses to treadmill running performed at similar VO2.

scholarly journals Effects of a Wearable Carriage Aid on Whole-Body Physiological Measures and Balance

2020 ◽  
Vol 10 (22) ◽  
pp. 8076
Author(s):  
Saad A. Alabdulkarim ◽  
Abdulsalam M. Farhan ◽  
Mohamed Z. Ramadan
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Minute Ventilation ◽  
Aid Effectiveness ◽  
Whole Body ◽  
Physiological Measures ◽  
Future Studies ◽  
Lower Back ◽  
The Impact ◽  
Load Mass

Carriage tasks are common and can lead to shoulder and lower back injuries. Wearable carriage aids have shown mixed effects on local physical demand measures. This study examined the impact of a wearable carriage aid on whole-body physiological measures (normalized oxygen consumption, minute ventilation, respiratory rate, and heart rate) to obtain a more comprehensive assessment regarding aid effectiveness. Additionally, this study investigated the effect of wearing the device on perceived balance. The potential moderating effect of carried load mass was considered. The examination was conducted while walking on a treadmill at a constant speed (2 km/h) for 5 min and was completed by 16 participants. Wearing the device reduced normalized oxygen consumption (~14%), minute ventilation (~7%), and heart rate (~3%), while substantially improving perceived balance (~61%). These effects were consistent across examined carried load levels. Although this study highlighted the potential for the developed aid, future studies are required for more diverse and realistic testing conditions.

Surface Area of the Euphausiid Thysanöessa raschii and Its Relation to Body Length, Weight, and Respiration

1977 ◽  
Vol 34 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Gareth C. H. Harding
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Surface Area ◽  
Body Length ◽  
External Surface ◽  
Dry Weight ◽  
External Surface Area ◽  
Marine Crustaceans ◽  
Respiratory Surface ◽  
Wet Weight

A method is described for estimating the surface area of marine crustaceans. The external surface area of the euphausiid Thysanöessa raschii (M. Sars) is proportional to length2.4, dry weight0.95, and wet weight0.84. Oxygen consumption is proportional to wet weight0.82, which indicates that respiration should be proportional to respiratory surface area. The implications of this finding regarding the relations of metabolic rate, size, and surface area are discussed in a broader framework by comparing them with similar studies on vertebrates and other invertebrates.

Physiology of 1-Mile Walk Test in Older Adults

1995 ◽  
Vol 3 (4) ◽  
pp. 373-382 ◽  
Author(s):  
Carmelo Bazzano ◽  
Lee N. Cunningham ◽  
Giovanni Cama ◽  
Tony Falconio
Keyword(s):  
Older Adults ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Cardiovascular Diseases ◽  
Minute Ventilation ◽  
Walk Test ◽  
Healthy Older Adults ◽  
Older Subjects ◽  
Physiologic Data

This study examined the physiology of the 1-mile walk test as administered in the field with 16 (7 M, 9 F) older adults (mean age 66.1 ± 5.9 yrs). Physiologic data were obtained via a Cosmed K2 miniaturized O2analyzer with telemetric capabilities during a maximal treadmill (TM) test and a 1-mile walk test (MWT). Oxygen consumption (ml · kg−1· min−1), minute ventilation (L · min−1), and heart rate (b · min−1) values obtained at maximal levels on the TM were 25.6 ± 7.6, 57 ± 17, and 155 ± 16, respectively. The measured V̇O2submax during the MWT was 18.5 + 5, V̇Esubmax was 44 ± 10, and HR submax was 140 ± 19. The subjects were able to hold 74% of the V̇O2max, 81% of V̇Emax, and 91% of HR max. An upward drift for HR and V̇Ewas noted while V̇O2remained constant throughout the MWT. The MWT with older subjects requires a vigorous level of metabolic and cardiorespiratory intensity. For healthy older adults who have been properly screened for hidden metabolic and cardiovascular diseases, participation in the MWT appears feasible.

Oxygen uptake by embryos and ovigerous females of two intertidal crabs, Heterozius rotundifrons (Belliidae) and Cyclograpsus lavauxi (Grapsidae): scaling and the metabolic costs of reproduction

2001 ◽  
Vol 204 (6) ◽  
pp. 1083-1097 ◽  
Author(s):  
H.H. Taylor ◽  
N. Leelapiyanart
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Metabolic Cost ◽  
Initial Energy ◽  
Egg Mass ◽  
Metabolic Rates ◽  
Blastula Stage ◽  
Female Crab ◽  
Metabolic Scaling ◽  
Intertidal Habitats

Heterozius rotundifrons and Cyclograpsus lavauxi are crabs of similar size, whose intertidal habitats overlap. They differ in the number and size of their eggs. A 2 g ovigerous H. rotundifrons incubates 675 large yolky eggs (mean single-egg mass 269 microg; egg clutch 9.15 % of mass of female crab; increasing to 435 microg and 13.4 % at hatching). The egg clutch of a 2 g C. lavauxi is larger (15.4 % of crab mass increasing to 18.9 % at hatching) and contains more numerous (28 000), smaller (10.9 microg increasing to 20.3 microg) eggs. The longer development time of the larger eggs (194 days versus 56 days at 15 degrees C) results from a delayed increase in metabolic rate (diapause) and not metabolic scaling. On the basis of the total mass of single eggs, the mass-specific metabolic rates of early embryonic stages of H. rotundifrons (0.72 micromol g(−1)h(−1) for the blastula stage at 15 degrees C) and C. lavauxi (1.13 micromol g(−1)h(−1)) were similar to those of the adult female crabs (0.70 micromol g(−1)h(−1) for H. rotundifrons and 0.91 micromol g(−1)h(−1) for C. lavauxi) and increased 13- and 10-fold, respectively, by the time of hatching. Thus, early embryonic metabolic rates were much lower than expected from their mass, but the metabolic rates of pre-hatching embryos were consistent with the allometry of juveniles and adults. Possible interpretations of this apparently anomalous scaling of embryonic metabolic rates are discussed. Mass-specific rates of oxygen consumption by ovigerous females (including the eggs) of both species were higher than for non-ovigerous crabs, in water and in air, and increased greatly during the development of the eggs. This difference was attributable mainly to the increasing metabolic rates of the attached embryos, but early ovigerous crabs (blastula stage) of both species also demonstrated a small elevation in metabolic rate by the crab itself, i.e. a metabolic cost of egg-bearing. In contrast, the elevation of the rate of oxygen consumption by late ovigerous females of C. lavauxi was less than predicted from the metabolic rate of eggs in a stirred respirometer. This suggests that, towards the end of development in C. lavauxi, the oxygen supply to the eggs in situ may be diffusion-limited by unstirred layers, an effect not observed for the larger eggs and more open egg clutch of H. rotundifrons. The cost of development, in terms of total oxygen consumption of single eggs, from extrusion to hatching, was 3.34 micromol O2 (approximately 1.5 J) for H. rotundifrons and 0.105 micromol O2 (approximately 0.05 J) for C. lavauxi. This 30-fold ratio approximates the ratios of their initial masses and yolk contents but represents only approximately one-third of the initial energy contents of the eggs.

Similitude in the cardiovascular system of mammals

2001 ◽  
Vol 204 (3) ◽  
pp. 395-407 ◽  
Author(s):  
T. Dawson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cardiovascular System ◽  
Body Mass ◽  
Scaling Laws ◽  
Basic Design ◽  
Experimental Basis ◽  
Additional Insight ◽  
Scaling Relationships ◽  
Rate Of Oxygen Consumption

Scaling laws governing the cardiovascular system of mammals are discussed in the present review in a manner emphasizing their experimental basis. Specific attention is given to the well-known experimental laws requiring the rate of oxygen consumption and the heart rate of mammals to vary with body mass raised to the powers 3/4 and −1/4, respectively. This review involves reconsideration and further discussion of the previous work of the writer in which these and other scaling relationships were developed from fundamental considerations. The predicted scaling laws remain unchanged from the earlier work, but alternative assumptions leading to the laws are used so as to provide additional insight. The scaling laws are shown to have their origin in the basic design of the cardiovascular system and in the basic processes involved in its working. Modification of the design assumptions of the system to account for known differences in the relative heart masses of mammals and birds is shown to lead to the scaling laws for rate of oxygen consumption and heart rate of birds.

scholarly journals Severe spontaneous bradycardia associated with respiratory disruptions in rat pups with fewer brain stem 5-HT neurons

2009 ◽  
Vol 296 (6) ◽  
pp. R1783-R1796 ◽  
Author(s):  
Kevin J. Cummings ◽  
Kathryn G. Commons ◽  
Kenneth C. Fan ◽  
Aihua Li ◽  
Eugene E. Nattie
Keyword(s):  
Heart Rate ◽  
Metabolic Rate ◽  
Breathing Pattern ◽  
Neonatal Period ◽  
Vehicle Control ◽  
Accurate Assessment ◽  
Breathing Frequency ◽  
Cardiorespiratory Control ◽  
Rat Pups ◽  
Novel Method

The medullary 5-HT system has potent effects on heart rate and breathing in adults. We asked whether this system mitigates the respiratory instability and bradycardias frequently occurring during the neonatal period. 5,7-Dihydroxytryptamine (5,7-DHT) or vehicle was administered to rat pups at postnatal day 2 (P2), and we then compared the magnitude of bradycardias occurring with disruptions to eupnea in treated and vehicle control littermates at P5–6 and P10–12. We then used a novel method that would allow accurate assessment of the ventilatory and heart rate responses to near square-wave challenges of hypoxia (10% O2), hypercapnia (5 and 8% CO2 in normoxia and hyperoxia), and asphyxia (8% CO2-10% O2), and to the induction of the Hering-Breuer inflation reflex (HBR), a potent, apnea-inducing reflex in newborns. The number of 5-HT-positive neurons was reduced ∼80% by drug treatment. At both ages, lesioned animals had considerably larger bradycardias during brief apnea; at P5–6, average and severe events were ∼50% and 70% greater, respectively, in lesioned animals ( P = 0.002), whereas at P10–12, events were ∼ 23% and 50% greater ( P = 0.018). However, lesioning had no effect on the HR responses to sudden gas challenge or the HBR. At P5–6, lesioned animals had reduced breathing frequency and ventilation (V̇e), but normal V̇e relative to metabolic rate (V̇e/V̇o2). At P10–12, lesioned animals had a more unstable breathing pattern ( P = 0.04) and an enhanced V̇e response to moderate hypercapnia ( P = 0.007). Within the first two postnatal weeks, the medullary 5-HT system plays an important role in cardiorespiratory control, mitigating spontaneous bradycardia, stabilizing the breathing pattern, and dampening the hypercapnic V̇e response.

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