scholarly journals Intensity Paradox—Low-Fit People Are Physically Most Active in Terms of Their Fitness

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2063
Author(s):  
Henri Vähä-Ypyä ◽  
Harri Sievänen ◽  
Pauliina Husu ◽  
Kari Tokola ◽  
Tommi Vasankari

Depending on their cardiorespiratory fitness (CRF), people may perceive the exertion of incident physical activity (PA) differently. Therefore, the use of relative intensity thresholds based on individual fitness have been proposed to evaluate the accumulation of PA at different intensity levels. A subsample of the FinFit2017-study, 1952 adults (803 men and 1149 women) aged 20–69 years, participated in this study. Their maximal oxygen uptake (VO2max) was predicted with a 6 min walk test, and they were instructed to wear a triaxial hip-worn accelerometer for one week. The participants were divided into CRF tertiles by five age groups and sex. Raw acceleration data were analyzed with the mean amplitude deviation method in 6 s epochs. Additionally, the data were smoothed with 1 min and 6 min exponential moving averages. The absolute intensity threshold for moderate activity was 3.0 metabolic equivalent (MET) and for vigorous 6.0 MET. Correspondingly, the relative thresholds were 40% and 60% of the oxygen uptake reserve. Participants in the lowest CRF tertile were the most active with relative thresholds, and participants in the highest CRF tertile were the most active with absolute thresholds. High-fit people easily reached the absolute thresholds, while people in the lowest CRF tertile had to utilize most of their aerobic capacity on a daily basis simply to keep up with their daily chores or peers.

1977 ◽  
Vol 32 (11-12) ◽  
pp. 908-912 ◽  
Author(s):  
H. J. Schmidt ◽  
U. Schaum ◽  
J. P. Pichotka

Abstract The influence of five different methods of homogenisation (1. The method according to Potter and Elvehjem, 2. A modification of this method called Potter S, 3. The method of Dounce, 4. Homogenisation by hypersonic waves and 5. Coarce-grained homogenisation with the “Mikro-fleischwolf”) on the absolute value and stability of oxygen uptake of guinea pig liver homogenates has been investigated in simultaneous measurements. All homogenates showed a characteristic fall of oxygen uptake during measuring time (3 hours). The modified method according to Potter and Elvehjem called Potter S showed reproducible results without any influence by homogenisation intensity.


Physica ◽  
1938 ◽  
Vol 5 (9) ◽  
pp. 898-900 ◽  
Author(s):  
J. Clay ◽  
P.H. Clay

1845 ◽  
Vol 1 ◽  
pp. 371-371
Author(s):  
Kelland

This Memoir is the prosecution of a subject on which the author had previously touched in a paper which is printed in the seventh volume of the Transactions of the Cambridge Philosophical Society. It has for its object the investigation of the quantity of light which is received on a screen of unlimited dimensions, after passing through a certain aperture, or suffering reflexion at two mirrors. The end for which the investigation is undertaken is to ascertain the constant which must be introduced in using Huygens's principle.


Author(s):  
Danilo Buonsenso ◽  
Cristina De Rose ◽  
Rossana Moroni ◽  
Piero Valentini

ABSTRACTIntroductionThe impact of school opening on the SARS-CoV-2 pandemic is still unknown. This study aims to provide preliminary information about the number of SARS-CoV-2 cases among students attending Italian schools.MethodsData are extracted and analysed from an open access, online dataset that monitor, on a daily basis, media news about SARS-CoV-2 infections of students attending Italian schoolsResultsAs of 5 October 2020, a total of 1350 cases of SARS-CoV-2 infections have been registered in the Italian territory schools (involving 1059 students, 145 teachers and 146 other school members), for a total of 1212 out of 65104 (1.8%) Italian schools involved. National schools reported only 1 case of SARS-CoV-2 infection in more than 90% of cases, and only in one high school a cluster of more than 10 cases have been described (P 0.015). The detection of one or more SARS-CoV-2 infections leaded to the closure of 192 (14.2%) entire schools, more frequently nursery/kindergartens (P<0.0005).DiscussionOur preliminary data support low transmission of SARS-CoV-2 within schools, at least among younger students. However, entire schools are frequently closed in the fear of larger outbreaks. Continuous monitoring of school settings, hopefully through daily updated open access datasets, are needed to better understand the impact of schools on the pandemic, and provide guidelines that better consider different risks within different age groups.


Author(s):  
Damir Zubac ◽  
Vladimir Ivančev ◽  
Zoran Valić ◽  
Boštjan Šimunič

We studied the effects of age on different physiological parameters, including those derived from (i) maximal cardiopulmonary exercise testing (CPET), (ii) moderate-intensity step transitions, and (iii) tensiomyography (TMG)-derived variables in moderately active women. Twenty-eight women (age, 19 to 53 years), completed 3 laboratory visits, including baseline data collection, TMG assessment, maximal oxygen uptake test via CPET, and a step-transition test from 20 W to a moderate-intensity cycling power output (PO), corresponding to oxygen uptake at 90% gas exchange threshold. During the step transitions, breath-by-breath pulmonary oxygen uptake, near infrared spectroscopy derived muscle deoxygenation (ΔHHb), and beat-by-beat cardiovascular response were continuously monitored. There were no differences observed between the young and middle-aged women in their maximal oxygen uptake and peak PO, while the maximal heart rate (HR) was 12 bpm lower in middle-aged compared with young (p = 0.016) women. Also, no differences were observed between the age groups in τ pulmonary oxygen uptake, ΔHHb, and τHR during on-transients. The first regression model showed that age did not attenuate the maximal CPET capacity in the studied population (p = 0.638), while in the second model a faster τ pulmonary oxygen uptake, combined with shorter TMG-derived contraction time (Tc) of the vastus lateralis (VL), were associated with a higher maximal oxygen uptake (∼30% of explained variance, p = 0.039). In conclusion, long lasting exercise involvement protects against a maximal oxygen uptake and τpulmonary oxygen uptake deterioration in moderately active women. Novelty: Faster τ pulmonary oxygen uptake and shorter Tc of the VL explain 33% of the variance in superior maximal oxygen uptake attainment. No differences between age groups were found in τ pulmonary oxygen uptake, τΔHHb, and τHR during on-transients.


2019 ◽  
Vol 44 (6) ◽  
pp. 681-684 ◽  
Author(s):  
E. Madison Jenkins ◽  
Leah N. Nairn ◽  
Lauren E. Skelly ◽  
Jonathan P. Little ◽  
Martin J. Gibala

We investigated the effect of stair climbing exercise “snacks” on peak oxygen uptake. Sedentary young adults were randomly assigned to perform 3 bouts/day of vigorously ascending a 3-flight stairwell (60 steps), separated by 1–4 h of recovery, 3 days/week for 6 weeks, or a nontraining control group (n = 12 each). Peak oxygen uptake was higher in the climbers after the intervention (P = 0.003), suggesting that stair climbing “snacks” are effective in improving cardiorespiratory fitness, although the absolute increase was modest.


1965 ◽  
Vol 20 (3) ◽  
pp. 432-436 ◽  
Author(s):  
K. Lange Andersen ◽  
Lars Hermansen

Maximal oxygen uptake and related respiratory and circulatory functions were measured in sedentary and well-trained middle-aged men. Maximal oxygen uptakes averaged 2.63 liter/min in sedentary men and 3.36 liter/min in well-trained men, the latter value being essentially the same as found in young untrained students. The heart rate/ oxygen uptake relationship was found to be the same for sedentary-living men, regardless of age, but maximal heart rate was lower in older men. The maximal heart rate is probably the same in well-trained as in sedentary middle-aged men, this in contrast to what has been observed in younger age groups, where training reduces maximal heart rate. The exercise-induced hyperventilation takes place at an oxygen uptake corresponding to 70–80% of the capacity, this being the same in trained and untrained, and essentially the same as found in young adult subjects. maximal O2 uptake Submitted on March 23, 1964


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