Search PubMed⌕ Search

Biomedical subjects

M Garcin

Publications and source records attributed to M Garcin.

At least 19 recordsLinked to original sources
PubMed2003

Reliability of rating scales of perceived exertion and heart rate during progressive and maximal constant load exercises till exhaustion in physical education students.

The purpose of this study was to assess the reliability of ratings of perceived exertion (RPE) and estimation of time limit (ETL) scales, and heart rate in physical education students during standardised and replicated progressive and constant load exercises till exhaustion realised on a track. Three groups of ten physical education students who present the same anthropometrical characteristics performed an incremental exercise to determine their maximal aerobic velocity (MAV) on an indoor track. Thereafter, group 1 performed an identical incremental exercise whereas groups 2 and 3 performed two identical exercises to exhaustion: a constant load exercise up to exhaustion at 90 and 100 % MAV, respectively, to determine the time to exhaustion at each intensity (tlim 90 and tlim 100). The results of this study were that MAV, tlim 90 and tlim 100 were not significantly different between the two trials. Moreover, the individual Pearson correlation coefficients between test and retests were very high (0.94 to 1). The slope and y intercept values of the relationships between test and retest perceived exertion ratings were not significantly different from the identity line. Moreover, test-retest differences in HR values fell within the 95 % LoA analysis. Consequently, HR values, RPE and ETL scales are reliable during standardised and replicated progressive and constant load exercises till exhaustion performed on a track with physical education students.

Adult↗
PubMed2002

The ratio HLa : RPE as a tool to appreciate overreaching in young high-level middle-distance runners.

The purpose of the present investigation was to study the effects of eight weeks of intensive training at the beginning of the athletic season on perceived exertion and on the ratio of blood lactate concentration to ratings of perceived exertion (HLa : RPE) in young runners. Eight high-level middle-distance runners performed two exhausting exercises on an indoor track before and after eight weeks of training. The first test was an incremental exercise to determine their maximal oxygen uptake (VO(2) max), the velocity associated with VO(2) max (vVO(2) max), the velocity of the lactate concentration threshold (vLT) and the velocity delta 50 (vDelta50 : the velocity halfway between vVO(2) max and vLT). The second test was a constant-load all-out run at vDelta50 to determine the time to exhaustion at this intensity (tlim vDelta50). There were five training sessions a week with interval training twice a week. After eight weeks of training, vVO(2) max, vLT and tlim vDelta50 were not significantly different. The athletes perceived exercise as being harder after training than before at a same given relative velocity in the incremental test. During the all-out run at vDelta50, they felt that, at the same given relative time, they could endure less after than before training. Moreover, the HLa : RPE ratio was significantly lower after intensive interval-training performed immediately after the holidays. Consequently, two interval-training sessions per week would induce an overreaching state that is not yet characterized by a decrease in performance and physiological values whereas perceived exertion (RPE, ETL) and especially the HLa : RPE ratio allows the detection of changes in young high-level middle-distance runners.

Adaptation, Physiological↗
PubMed2001

RPE responses during arm and leg exercises: effect of variations in spontaneously chosen crank rate.

The aim of this study was two-fold. First, the rating of perceived exertion (RPE) was compared between two different upper and lower body exercises. Subjects (n = 12) performed with spontaneously chosen crank or pedal rates: (i) incremental maximum power tests (Test 1), with an initial work rate of 50% of maximal power followed by increases of 10% at each 120-sec. work stage and (ii) tests (Test 2) with exercise bouts set at 20, 40, 60, and 80% of maximal power separated by passive recovery periods. Second, the effects of variations in spontaneously chosen crank rate on RPE was analysed using the second test performed only with upper body. Subjects performed Test 2 three times with crank rates spontaneously chosen by the subjects, set at plus or minus 20% of spontaneously chosen crank rate. During both Tests 1 and 2 for upper or lower body, RPE increased linearly (p<.01) with power output. No significant difference was noticed between upper and lower body tests; however, RPE was significantly different (p<.05) between Test 1 results for upper and lower body at 70, 80, 90, and 100% of maximal power. The greater RPE at high power output could be linked to the important effect of fatigue during upper body exercise. Among the three crank-rate conditions, no significant difference in RPE was noticed. The choice of crank rate does not seem to influence the perception of exertion in upper body cycling exercise.

Adult↗
PubMed2001

Does perceived exertion depend on glycemic index of foods ingested throughout three hours before a one-hour high-intensity exercise?

The purpose of this study was to assess the relationships between perceived exertion (RPE) and plasma glucose concentrations or hunger feelings during a 1-hr. bicycle submaximal exercise after ingestion of pre-exercise test foods with a different glycemic index. Each of endurance-trained male triathletes ingested three different glycemic index (GI) foods (HighGI: glucose, LowGI: whole-wheat biscuit or water) throughout the 3 hr. before exercise at 80% maximal oxygen uptake (VO2 max). RPE values increased as a logarithmic function of time. This result is opposite to results obtained with longer exercise bouts up to 3 hr. duration. RPE and hunger ratings were not significantly different for the three test foods whatever the time. Moreover, RPE did not correlate with plasma glucose concentrations during exercise. Consequently, RPE did not depend on the GI of the pre-exercise test foods during a 1-hr. exercise at 80% VO2 max. Physiological and psychological factors other than glycemic index may have mediated the perceptual responses during a 1-hr. high-intensity exercise. It is possible that during endurance exercise of longer duration, the level of blood glucose mediates the intensity of peripheral exertional perceptions arising from active skeletal muscle during prolonged exercise.

Adult↗
PubMed2001

Perceived exertion scales attest to both intensity and exercise duration.

The present purpose was to study the relationships between perceived exertion (RPE, ETL) and exercise duration for all-out runs eliciting vVO2 max. 12 endurance-trained men performed three exhausting exercises on an indoor track. The first test was an incremental exercise to measure their maximal oxygen uptake (VO2 max), the velocity associated with VO2 max (vVO2 max), the velocity of the lacate concentration threshold (vLT) and the velocity delta 50 (vdelta50: the velocity halfway between vVO2 max and vLT). The second and third tests were a constant load all-out run at vVO2 max and vdelta50 to measure the time to exhaustion at these intensities (tlim vVO2 max and tlim vdelta50, respectively). vdelta50 corresponded to 90.1 +/- 2.5% vVO2 max; tlim vVO2 max and tlim vdelta50 were equal to 286 +/- 71 sec. and 547+/- 157 sec., respectively. For a same given relative time (%tlim), athletes perceived exercise as harder and felt that they could endure less for vVO2 max than vdelta50. When subjects began to perceive exercise as "hard" (RPE = 15), they had run for only 36.4 +/- 26.8%tlim at vVO2 max, whereas they had run for 46.1 +/- 15.7 %tlim at vdelta50. These results indicate that RPE and ETL scales were a combined subjective estimation of both intensity and exercise duration for all-out runs at 90 and 100% vVO2 max. Therefore, this scale could be used to assess duration as well as intensity of exercise for the practical application in sport. Moreover, it could be suggested that exercise duration can be prescribed as a function of perceived exertion for healthy normal people. Consequently, perceived exertion could be an important tool to individualize the prescription of a training program.

Adult↗
PubMed1999

A new rating scale of perceived exertion based on subjective estimation of exhaustion time: a preliminary study.

Perceived exertion has been investigated during incremental exercise to exhaustion with athletes, according to the 6-20 scale proposed by Borg (RPE, 1970) and a new scale based on the estimation of exhaustion time (t(lim)) (Estimated Time Limit or ETL, from 1 to 20; ETL= 21 - 2 n, with n = log2t(lim)). ETL increased linearly with the percentage of maximal aerobic power (%MAP) up to the ventilatory threshold (VT). Beyond VT, an inflection of the ETL-%MAP relationship was observed. RPE and ETL calculated at VT were equal to 15 +/- 1.7, i.e. an exercise intensity perceived as "hard", and 10 +/- 2.3, i.e. an estimated exhaustion time equal approximately to 45 minutes. Standard deviations for RPE and ETL at VT were too large for an accurate estimation of this threshold. The results of the present study suggest that RPE and ETL should be used in addition to physiological data, but not replace them in the prescription of a training program.

Adult↗
PubMed1998

Ratings of perceived exertion (RPE) during cycling exercises at constant power output.

The purpose of the present investigation was to study the overall rating of perceived exertion (RPEov) according to the 6-20 scale proposed by Borg (1970) and muscular RPE (RPEmu) in exercises at constant load. The relationship between RPE and heart rate for three different loads was studied during exhausting exercises in 10 participants. Whether the drift of RPE during a 20 min exercise at constant load could be an index of the endurance time during long-lasting exercises at constant load was also investigated. At 1-week intervals, the participants performed cycling exercises up to exhaustion at 60, 73, and 86% maximal aerobic power (MAP) measured during an incremental test. Heart rate, RPEov, RPEmu and exhaustion time (tlim) were measured. The upward shift of the HRmax-RPE regressions was significant between 86, 73 and 60% MAP (p < 0.001) for RPEov and RPEmu. This result suggests that the equation HR = 10 x RPE proposed by Borg (1973) for incremental exercise is not valid for long-lasting exercise at constant load until exhaustion because the heart rate corresponding to a given RPE depends on load and time. Mean RPE increased linearly with time up to exhaustion. Unexpectedly, the relationships between RPEmu or RPEov and percentage of exhaustion time were similar for exercises at 60 and 73% MAP although the exhaustion times were very different (79.40 +/- 30.64 min versus 36.19 +/- 15.99 min, respectively) (p < 0.001). Consequently, it is likely that RPE was a subjective estimation of the hardness of exercise rather than the intensity of exercise. The RPE pattern at the beginning of long-lasting exercises at constant load (60 and 73% MAP) cannot be considered as a sensitive predictor of the point of self-imposed exhaustion for individuals. Indeed, the errors in the estimation of exhaustion time from extrapolation of RPE at the beginning of exercise were very large. Moreover, at 60% MAP, a steady-state in RPE was observed during 20 min in five subjects whose tlim were not longer than tlim of the other subjects. In addition, the data of the present study indicate that RPEmu could be more useful than RPEov in cycling.

Adult↗
PubMed1998

Ratings of perceived exertion (RPE) as an index of aerobic endurance during local and general exercises.

The main purpose of this study was to assess the correlations of RPE with indicators of endurance (critical power), exhaustion time and the electromyographic activity of a relevant muscle during general and local exercises. Eight healthy subjects participated in the study. During the first session, Maximal Aerobic Power (MAP) was measured by means of an incremental cycling exercise on a Monark ergometer. At 1-week intervals the participants performed a general or local exhausting exercise, which consisted of a cycle exercise (60, 73, 86 or 100% MAP) and a knee extension exercise (lifting a load between 17.5 and 32.5 kg every 3 s), respectively. The critical powers corresponding to cycling (CPcycling) and knee extension (CPknee) were calculated from the slope of the linear relationship between exhaustion time (tlim) and work. Rate of perceived exertion, concerning the whole body (overall RPE [RPEov]), RPE concerning the exercising muscles (muscular RPE [RPEmu]) and exhaustion time were measured. During the last session, the integrated electromyogram of the right Vastus Lateralis (iEMG s-1) was measured during short (20 s) cycling and knee extension non-exhausting exercises, with the same electrode location, at the different power outputs used during the exhausting exercises. The relationships between RPEmu at the fifth minute and log tlim and between iEMG% (percentage of the iEMG s-1 corresponding to 100% MAP during cycling) and log tlim were similar for the cycling and knee extension exercises. The mean values of RPEmu at the fifth minute of exercise calculated for CPcycling and CPknee were almost equal (12.3 +/- 1.7 versus 12.2 +/- 0.9). Similarly, the mean values of iEMG% corresponding to CPcycling and CPknee were equal (78.44 versus 79.02%). These results suggest that RPEmu is related to aerobic endurance and that the possibility of sustaining a high percentage of maximal aerobic power during a general exercise is mainly related to local muscular factors.

Adult↗
PubMed1996

Physiological strains while pushing or hauling.

An experiment has been designed to compare two ways of load moving: pushing with a bar or hauling with a pelvic belt, against the same resistances, at the same speeds. This study has been carried out in the laboratory on a treadmill, using two groups: 15 healthy sedentary men and 10 endurance trained male athletes. The task consisted of pushing or hauling against the same resistance (3, 5 and 7 kg for the first group and 6, 8, 9 and 10 kg for the second) at two walking speeds (3 and 4 km. h-1 for the first group and 3.7 and 4.7 km.h-1 for the second). The physiological strains were studied by measuring heart rate (HR) and oxygen consumption (VO2) in both experiments. In addition, perceived exertion was estimated in the second group according to a rating scale of perceived exertion (RPE). Analysis of variance showed that pushing with the arms was more strenuous than hauling with a pelvic belt with regard to HR, VO2 and RPE (P < 0.01). When resistances and speeds were grouped, the differences between pushing and hauling were equal to 3 beats min-1, 0.85 ml. min-1. kg-1 for HR and VO2, respectively, for the first experiment (sedentary subjects), whereas the differences were equal to 11.4 beats. min-1, 1.66 ml.min-1.kg-1 and 2.15 for HR, VO2 and RPE, respectively, for the second experiment (trained endurance athletes). In the endurance athletes, there was a parallel upward shift of the VO2-HR linear relationship for pushing (covariance analysis, P < 0.01), which suggested that an element of static work (pushing with the upper limbs) added to the dynamic work could explain the higher physiological cost during pushing.

Adult↗
PubMed1996

Use of physiological criteria for improving physical work conditions.

Physical work is still present in many countries, specially in developing ones. The physiological analysis of the work load could be conducted through two different ways, referring to his energetic cost and/or to the mechanical power of the human motor. The purpose of ergonomics is to organize any physical professional task in order to maintain the workers as much as possible inside the limits of a fatiguing activity. The process of fatigue affects differently a "general activity" and a "local work." If a worker is engaged in a general hard activity, like carrying a load or pushing a trolley, an increase of oxygen consumption or/and an acceleration of the heart rate could be observed. This latter, allowing to estimate the oxygen cost of the work, is more affected if the work is performed in a hot environment. In order to establish the ratio between the data observed at the work place and the maximal working capacity of the organism, it is possible to experiment with the physiological effects of transitory increases of the work stress, by increasing the load or/and the frequency of the repetition of the "unit" of work done. When the task could be described in terms of local work, the correct methodology is based upon the general rules established respectively for the static and the dynamic work. In both the cases, it is possible to determine the critical rate of the muscular activity, the part of the muscular capacity engaged at the work place and the probable time for local exhaustion, in order to limit the duration of each period of work. It should be remembered that 50 years ago, Lucien Brouha proposed that heart rate determinations at work be used as a criteria for a better organization of human work by a non-sophisticated method.

Biomechanical Phenomena↗
PubMed1987

[Our attitude in functional vocal pathology].

After underlining the frequency of organic lesions observed in functional diseases of vocal cords, emphasis is placed on the importance of the phonetogram in their evaluation and video-laryngo-stroboscopic investigation in their diagnosis. When surgery is necessary, stainless steel instruments are preferred to the laser. Respective isolated or associated vocal reeducational and surgical indications are discussed, and the establishment of a team including laryngologist, phoniatrist and orthophonist recommended to ensure most effective results.

Cysts↗
PubMed1986

Melanotic neurofibroma: a case report with ultrastructural study.

The authors report a case of a solitary melanotic neurofibroma involving the temporomalar area in a 17-year-old man. Light-microscopic study reveals a benign neurofibroma including melanin deposits. Electron microscopy shows typical premelanosomes and melanosomes within Schwann cell cytoplasm. The literature is reviewed, and theories of histogenesis for this unusual tumor are discussed.

Adolescent↗
PubMed1983

[Current histopathological findings in Ménière's disease].

Controversy exists as to the presence of ruptures of the membranous labyrinth in patients with Meniere's disease, some authors considering the lesions reported to be artefacts only. Confirmation of the existence of healed labyrinthine tears was obtained in all cases of clinically and histopathologically confirmed Menière's disease studied by means of a protocol involving strict criteria. Lesions were observed mainly in Reissner's membrane and demonstrated three particular aspects. It is suggested that the images described by Out-Pouch in the posterior labyrinth are also the result of healed ruptures.

Cochlear Duct↗
PubMed1982

[Use of a microcomputer for simplified data processing of ENT case-records employing a commercial program (author's transl)].

Combined use of a microcomputer of sufficient capacity and a commercial program for data processing permits simple storage and exploitation of hospital case-records in an ENT department of moderate size. The principal advantages of the system reside in its permanent availability, the ease of communication with the computer due to the clear language employed, its large storage capacity (650 case-records per diskette), and the moderate cost involved. Programming time is reduced by the use of a particular nomenclature for questions and possible replies. The system is not static, and can be adapted to individual needs or modifications in pathology.

Computers↗