Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “work intensity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Work intensity of regional industrial physicians and specialists in the Occupational Health Care Units in Poland 1981-1986].

The paper contains an analysis of condition of resources and scope of activity of all Industrial Health Care Units in Poland in the period between 1981-1986. Special attention is given to the problems of medical staff, especially industrial physicians and different specialists working for these Units. The relationship was discussed between the existing resources and the Units. The relationship was discussed between the existing resources and the Units activity. The activity was understood as the number of consultations given both in cases of spontaneous attendance and prophylactic (including periodical) medical examination. Also, disproportions between these two types of consultations were discussed. The results were interpreted in detail, so that the cause-effect relationships could be found. The sense and potential advantages coming from this analysis were presented.

Ambulatory Care Facilities↗
PubMed2006

Oxygen consumption and metabolite concentrations during transitions between different work intensities in heart.

Steady-state metabolite (ADP, ATP, P(i), PCr, and NADH) concentrations usually differ little between different workloads with significantly different oxygen consumption rates in the heart. However, during transitions between steady states, metabolite concentrations may in some cases change transiently, exhibiting a significant overshoot or undershoot, whereas in other cases they approach near-exponentially new steady-state values. Oxygen consumption rate usually reaches the new steady-state value very quickly (within a few seconds). The present in silico studies, performed using a previously developed computer model of oxidative phosphorylation in the heart, demonstrate that such a behavior of the oxidative phosphorylation system can be reproduced only under the assumption that ATP usage, substrate dehydrogenation, and (particular steps of) oxidative phosphorylation are directly activated to a similar extend by some cytosolic factor/mechanism during transition from low work to high work (the so-called parallel-activation mechanism). Computer simulations show that some differences observed between different experimental systems can be explained by a slightly different balance of the activation of particular components of the system and/or by a delay in time of the activation/inactivation of substrate dehydrogenation and oxidative phosphorylation during low-to-high and high-to-low work transitions. Thus the presented theoretical approach offers a general idea that is able to unify, at least semiquantitatively, different experimental data available in the literature.

Adenosine Triphosphate↗
PubMed1980

Effect of work intensity and duration on recovery O2.

This study was undertaken to determine the effects of exercise intensity and duration on the time course and magnitude of recovery O2. Eighteen men exercised at 50, 65, and 80% of maximal O2 consumption (VO2max) for 5 and 20 min. Each exercise bout was preceded and followed by cycling at 150 kpm.min-1, which established the base-line VO2 used in this study. The magnitude of the rapid component of recovery O2 was proportional to exercise intensity and was not altered by exercise duration. The slow component of recovery O2 was not significantly altered by exercise intensity or duration at 50 and 65% of VO2max. However, after 20 min of exercise at 80% of VO2max, the slow component of recovery 02 was 5 times (p less than 0.01) larger than after the 5-min exercise at 80% of VO2max. End-exercise blood lactate level was also higher after the 20-min bout at 80% of VO2max; however, at most, 30% of the difference between the magnitude of the slow components of recovery O2 after the 5- and 20-min rides at 80% of VO2max could be accounted for by lactate metabolism. The Q10 effect of temperature on metabolism could account for 60-70% of the slow components of recovery O2 at all work rates and durations. It could also account for the remaining 70% of the increase in the slow component after the 20-min exercise at 80% of VO2max.

Adult↗
PubMed1995

Effect of drafting on work intensity in classical cross-country skiing.

The purpose of this study was to compare the heart rate responses during cross-country skiing as a leading skier, as well as in a drafting situation, three meters behind the leader. Eight male and two female cross-country ski racers, paired for skiing ability, skied a 2 km course (two loops of 1 km) using the diagonal stride and double-poling techniques at a fixed speed (4.75 m.s-1 and 4.45 m.s-1 for males and females respectively) on two different occasions, once as a leading skier, the other as a drafter. A recovery period of 30 minutes was allowed between the two trials. Heart rates (HR) were registered every five seconds during all performances. Results revealed that HR were significantly lower (165 vs 172 beats.min-1) when skiing behind another skier as opposed to leading. Results also revealed that projected frontal areas appeared to influence the effects of drafting such that the HR differences between the leading and the drafting situations were larger for smaller skiers drafting behind larger skiers. These results showed that skiing behind another skier in a classical cross-country ski race would be very advantageous when the situation is encountered and could help racers using this energy saving strategy.

Adult↗
PubMed1991

Muscle ATP loss and lactate accumulation at different work intensities in the exercising Thoroughbred horse.

The effect of 2 min treadmill exercise, at speeds of 6-12 m.s-1 on an incline of 5 degrees, upon muscle adenine nucleotide loss and lactate accumulation was studied in six Thoroughbred horses. Minimal change occurred in the adenosine triphosphate (ATP) content of the middle gluteal muscle at speeds of 10 m.s-1 or less, but significant loss (up to 47%) had occurred in all horses by 12 m.s-1. The decline in ATP significantly correlated with the accumulation of muscle lactate, beginning shortly after the accumulation of 40 mmol.kg-1 dry muscle lactate. Decline in muscle ATP was mirrored closely by the appearance of ammonia, and to a lesser extent, hypoxanthine and uric acid in plasma. The results suggest that peak accumulation of any of these, or simply the concentration at a specified recovery time, may be used as a measure of ATP loss in the musculature as a whole. This was not so in the case of xanthine, which may also be formed from the degradation of guanidine nucleotides. An In-In plot of plasma ammonia against treadmill speed indicated a break point in accumulation between 8 and 9 m.s-1. The kinetics of ammonia accumulation with speed differed from those of lactate.

Adenosine Triphosphate↗
PubMed1979

Work intensities of different modes of exercise testings in clinical use.

Several different exercise testings with treadmill, bicycle ergometer and two-step were carried out by healthy Japanese men to study oxygen consumption per minute and circulatory responses. Stress imposed on the heart by dynamic leg exercise varied depending on the mode of exercise even if energy expenditure expressed in VO2 was identical. This should be fully taken into consideration in comparison of results of different modes of exercise testing. For estimation of VO2 during treadmill slope walk, an equation was derived by multiple regression analysis with use of belt speed and slope as independent variables.

Adult↗
PubMed1987

Ergonomics and the effects of vibration in hand-intensive work.

Along with ergonomic factors, such as forceful and repeated exertion and certain postures, vibration has been cited as a factor of chronic nerve and tendon disorders such as carpal tunnel syndrome and tendinitis. The arguments for the contribution of vibration come from epidemiologic studies, clinical case analyses, and studies of short-term effects. It is well established that vibration stimulates muscle contraction, which is called the tonic vibration reflex. It is also known that vibration reduces tactility and that tactility affects the amount of force exerted to hold or manipulate a given object. For localized vibration exposure of the hand and arm to occur, the hand must grip a vibrating object. Vibration may increase the risk of chronic tendon and nerve disorders by increasing the force exerted in repetitive manual tasks. This close relationship between force and vibration, and difficulties in measuring force and vibration in manual work, makes it very difficult to determine their relative contributions in epidemiologic and clinical studies.

Carpal Tunnel Syndrome↗