An Increasing Work RATE Test for Assessing the Physiological Strain of Submaximal Exercise

1974 ◽  
Vol 46 (2) ◽  
pp. 191-206 ◽  
Author(s):  
S. G. Spiro ◽  
E. Juniper ◽  
P. Bowman ◽  
R. H. T. Edwards

1. A progressive exercise test was performed on forty-four male and twenty-nine female healthy Europeans, aged between 20 and 64 years. Values for cardiac frequency (fH) and ventilation (V̇) were interpolated to standard (submaximal) oxygen uptakes (V̇o2) of 0·751/min and 1·01/min. The tidal volume (Vt) at a ventilation of 20 and 301 BTPS/min was also determined (Vt 20 and Vt 30 respectively). 2. The slope of the linear relationship between cardiac frequency or ventilation and oxygen uptake (SfH and SV̇ respectively) can be used as a measure of the fitness of an individual, as it indicates the increase in fH or V̇ that is obligatory for an increase in energy expenditure equivalent to an additional oxygen uptake of 1·0 1/min (about the increase necessary for walking on the level at a normal speed). By analogy with the responses of an athlete, a ‘fit’ subject is one in whom responses are economically low, i.e. SfH and SV̇ are lower than in sedentary individuals. Measures of SfH and SV̇ can also be used to indicate the demands of everyday activities on fH and V̇. 3. When SfH and SV̇ are related to the individual's capacity to adapt fH and V̇ from resting to predicted maximum values (‘adaptation capacity’ ACfH and ACV̇ respectively), the resulting index (SfH × 100/ACfH or SV̇ × 100/ACV̇) expresses the percentage of the adaptation capacity used for an additional energy expenditure equivalent to a V̇o2 of 1·01/min, and can be considered a measure of the ‘physiological strain’ of exercise. The effects on exercise responses of differences in body muscle can be allowed for by multiplying this index by lean body mass (LBM). The lower the (size-adjusted) physiological strain index, the fitter the individual subject.


2013 ◽  
Vol 38 (11) ◽  
pp. 1162-1165 ◽  
Author(s):  
Kym J. Guelfi ◽  
Rhiannon E. Halse

The effect of exercise on appetite and appetite-related hormones during pregnancy is not known. This study found that 30 min of moderate-intensity stationary cycling transiently attenuated hunger and increased fullness in late gestational women (n = 12). Exercise did not affect perceived appetite or appetite-related hormones in response to subsequent caloric consumption. These observations suggest that appetite responses do not intrinsically compensate for the additional energy expenditure induced by exercise, at least in the short term.



1970 ◽  
Vol 10 (47) ◽  
pp. 679 ◽  
Author(s):  
RH Weston

Measurements were made of the feed intakes, heart rates and bad., Y weights of adult sheep with a short fleece (0.3-1.2 cm) that were offered a low quality roughage diet and maintained in a cold environment. Feed intake was higher during cold exposure than under thermoneutral conditions. The increase in feed intake usually began in the second week of cold exposure and maximum intakes were generally shown in the third and fourth weeks. The increases were relatively small, the mean feed intakes in the third and fourth week of cold exposure being 9 to 15 per cent or 1.5-2.3 g organic matter/day/kg body weight above those under thermoneutral conditions. Heart rate values of up to 116 beats per minute during cold exposure indicated that energy expenditure was higher in the cold than under thermoneutral conditions. The increases in energy intake in the cold did not always compensate for the additional energy expenditure and body weight losses of up to 5.5 kg in four weeks of cold exposure were recorded. It was concluded that a regime of ad lib. feeding with low quality roughage would be of limited value in maintaining short fleeced sheep subjected to cold exposure. The data were also considered to be consistent with the conclusion that the intake of the wheaten hay diet was limited by the resistance of the dietary organic matter to removal from the rumen rather than by a metabolic effect of a nutrient deficiency.



Author(s):  
Andrew van der Vlies

Two recent debut novels, Songeziwe Mahlangu’s Penumbra (2013) and Masande Ntshanga’s The Reactive (2014), reflect the experience of impasse, stasis, and arrested development experienced by many in South Africa. This chapter uses these novels as the starting point for a discussion of writing by young black writers in general, and as representative examples of the treatment of ‘waithood’ in contemporary writing. It considers (spatial and temporal) theorisations of anxiety, discerns recursive investments in past experiences of hope (invoking Jennifer Wenzel’s work to consider the afterlives of anti-colonial prophecy), assesses the usefulness of Giorgio Agamben’s elaboration of the ancient Greek understanding of stasis as civil war, and asks how these works’ elaboration of stasis might be understood in relation to Wendy Brown’s discussion of the eclipsing of the individual subject of political rights by the neoliberal subject whose very life is framed by its potential to be understood as capital.



Author(s):  
Takeshi Ebihara ◽  
Kentaro Shimizu ◽  
Masahiro Ojima ◽  
Yohei Nakamura ◽  
Yumi Mitsuyama ◽  
...  


2021 ◽  
Vol 11 (5) ◽  
pp. 2228
Author(s):  
Daniela Galli ◽  
Cecilia Carubbi ◽  
Elena Masselli ◽  
Mauro Vaccarezza ◽  
Valentina Presta ◽  
...  

Reactive Oxygen Species (ROS) are molecules naturally produced by cells. If their levels are too high, the cellular antioxidant machinery intervenes to bring back their quantity to physiological conditions. Since aging often induces malfunctioning in this machinery, ROS are considered an effective cause of age-associated diseases. Exercise stimulates ROS production on one side, and the antioxidant systems on the other side. The effects of exercise on oxidative stress markers have been shown in blood, vascular tissue, brain, cardiac and skeletal muscle, both in young and aged people. However, the intensity and volume of exercise and the individual subject characteristics are important to envisage future strategies to adequately personalize the balance of the oxidant/antioxidant environment. Here, we reviewed the literature that deals with the effects of physical activity on redox balance in young and aged people, with insights into the molecular mechanisms involved. Although many molecular pathways are involved, we are still far from a comprehensive view of the mechanisms that stand behind the effects of physical activity during aging. Although we believe that future precision medicine will be able to transform exercise administration from wellness to targeted prevention, as yet we admit that the topic is still in its infancy.



2014 ◽  
Vol 39 (3) ◽  
pp. 324-328 ◽  
Author(s):  
Raffaele Milia ◽  
Silvana Roberto ◽  
Marco Pinna ◽  
Girolamo Palazzolo ◽  
Irene Sanna ◽  
...  

Fencing is an Olympic sport in which athletes fight one against one using bladed weapons. Contests consist of three 3-min bouts, with rest intervals of 1 min between them. No studies investigating oxygen uptake and energetic demand during fencing competitions exist, thus energetic expenditure and demand in this sport remain speculative. The aim of this study was to understand the physiological capacities underlying fencing performance. Aerobic energy expenditure and the recruitment of lactic anaerobic metabolism were determined in 15 athletes (2 females and 13 males) during a simulation of fencing by using a portable gas analyzer (MedGraphics VO2000), which was able to provide data on oxygen uptake, carbon dioxide production and heart rate. Blood lactate was assessed by means of a portable lactate analyzer. Average group energetic expenditure during the simulation was (mean ± SD) 10.24 ± 0.65 kcal·min−1, corresponding to 8.6 ± 0.54 METs. Oxygen uptakeand heart rate were always below the level of anaerobic threshold previously assessed during the preliminary incremental test, while blood lactate reached its maximum value of 6.9 ± 2.1 mmol·L−1 during the final recovery minute between rounds. Present data suggest that physical demand in fencing is moderate for skilled fencers and that both aerobic energy metabolism and anaerobic lactic energy sources are moderately recruited. This should be considered by coaches when preparing training programs for athletes.



2021 ◽  
Vol 32 (4) ◽  
pp. 91
Author(s):  
Alexander Rubtsov

In the article, the relationship between the highest professional specialization of philosophy and its involvement in the realities of everyday life consciousness, collective and individual, are considered. Karl Jaspers defines philosophy precisely through the natural need and ability of human being as such, from the piercing questions of children to the revelations of anomalous geniuses. Great philosophers only concentrate this sleeping ability in a person to see the world directly and every time anew. Rightly considered the most closed type of intellectual activity, philosophy at the same time provides examples of live communication and direct appeal to people and society.  The fact that each of us is the bearer of philosophical ideas (whether we are aware of it or not) leads to the problem of ideology. By analogy with the constitution of the political by Carl Schmitt through the opposition "friend — enemy", ideology is constituted by the opposition of "faith — knowledge" in a single continuum between the poles of "almost religion" and "almost philosophy". If ideology asserts the non-obvious as obvious, then the mission of philosophy is a systematic criticism of the obvious.  This conflict manifests itself both in society and in the consciousness of an individual.  The classic understanding of ideology as a purely external manipulation (“consciousness for the Other”) is challenged by the presence in the consciousness of the individual subject of “internal dialogue” and “internal speech” with the effects of ideological work and ideological struggle with oneself (the individual as a micromodel of society and the state).  Postmodern all the more accentuates the non-professional dimension of philosophy by rejecting the schemes of progress and hierarchy, the logic of binary oppositions, including high and low, center and marginal, specialized and amateur.  The ability to reflect is the most important feature of a sovereign personality in its resistance to the "penetrating" ideology and new mythology, degrading to intellectual barbarism and political savagery.



1988 ◽  
Vol 32 (15) ◽  
pp. 985-989 ◽  
Author(s):  
T. Mihaly ◽  
P.A. Hancock ◽  
M. Vercruyssen ◽  
M. Rahimi

An experiment is reported which evaluated performance on a 10-sec time interval estimation task before, during and after physical work on cycle ergometer at intensities of 30 and 60% VO2max, as scaled to the individual subject. Results from the eleven subjects tested indicate a significant increase in variability of estimates during exercise compared to non-exercise phases. Such a trend was also seen in the mean of estimates, where subjects significantly underestimated the target interval (10 seconds) during exercise. Subjects also performed more accurately with information feedback than without knowledge of results, but they were still not able to overcome the effects of exercise. As suggested by the experimental findings, decreased estimation accuracy and increased variability can be expected during physical work and is part of a body of evidence which indicates that exercise and its severity has a substantive impact on perceptual and cognitive performance.



2016 ◽  
Vol 53 (1) ◽  
pp. 179-187 ◽  
Author(s):  
José Vilaça-Alves ◽  
Nuno Miguel Freitas ◽  
Francisco José Saavedra ◽  
Christopher B. Scott ◽  
Victor Machado dos Reis ◽  
...  

AbstractThe aim of this study was to compare the values of oxygen uptake (VO2) during and after strength training exercises (STe) and ergometer exercises (Ee), matched for intensity and exercise time. Eight men (24 ± 2.33 years) performed upper and lower body cycling Ee at the individual’s ventilatory threshold (VE/VCO2). The STe session included half squats and the bench press which were performed with a load at the individual blood lactate concentration of 4 mmol/l. Both sessions lasted 30 minutes, alternating 50 seconds of effort with a 10 second transition time between upper and lower body work. The averaged overall VO2 between sessions was significantly higher for Ee (24.96 ± 3.6 ml·kg·min-1) compared to STe (21.66 ± 1.77 ml·kg·min-1) (p = 0.035), but this difference was only seen for the first 20 minutes of exercise. Absolute VO2 values between sessions did not reveal differences. There were more statistically greater values in Ee compared to STe, regarding VO2 of lower limbs (25.44 ± 3.84 ml·kg·min-1 versus 21.83 ± 2·24 ml·kg·min-1; p = 0.038) and upper limbs (24.49 ± 3.84 ml·kg·min-1 versus 21.54 ± 1.77 ml·kg·min-1; p = 0.047). There were further significant differences regarding the moment effect (p<0.0001) of both STe and Ee sessions. With respect to the moment × session effect, only VO2 5 minutes into recovery showed significant differences (p = 0.017). In conclusion, although significant increases in VO2 were seen following Ee compared to STe, it appears that the load/intensity, and not the material/equipment used for the execution of an exercise, are variables that best influence oxygen uptake.



2003 ◽  
Vol 62 (4) ◽  
pp. 777-781 ◽  
Author(s):  
Rosemary A. Richardson ◽  
H. Isobel M. Davidson

Common to both acute and chronic disease are disturbances in energy homeostasis, which are evidenced by quantitative and qualitative changes in dietary intake and increased energy expenditure. Negative energy balance results in loss of fat and lean tissue. The management of patients with metabolically-active disease appears to be simple; it would involve the provision of sufficient energy to promote tissue accretion. However, two fundamental issues serve to prevent nutritional demands in disease being met. The determination of appropriate energy requirements relies on predictive formulae. While equations have been developed for critically-ill populations, accurate energy prescribing in the acute setting is uncommon. Only 25–32% of the patients have energy intakes within 10% of their requirements. Clearly, the variation in energy expenditure has led to difficulties in accurately defining the energy needs of the individual. Second, the acute inflammatory response initiated by the host can have profound effects on ingestive behaviour, but this area is poorly understood by practising clinicians. For example, nutritional targets have been set for specific disease states, i.e. pancreatitis 105–147 KJ (25–35 kcal)/kg; chronic liver disease 147–168 kj (35–40 kcl)/kg, but given the alterations in gut physiology that accompany the acute-phase response, targets are unlikely to be met. In cancer cachexia attenuation of the inflammatory response using eicosapentaenoic acid results in improved nutritional intake and status. This strategy poses an attractive proposition in the quest to define nutritional support as a clinically-effective treatment modality in other disorders.



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