Project Aquarius 2. Limitations of Maximum Oxygen Uptake for Predicting the Strains of Building Fireline With a Rakehoe

1997 ◽  
Vol 7 (2) ◽  
pp. 77 ◽  
Author(s):  
JR Brotherhood ◽  
GM Budd ◽  
AL Hendrie ◽  
SE Jeffery ◽  
FA Beasley ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Pulmonary Ventilation ◽  
Average Energy ◽  
Rating Of Perceived Exertion ◽  
Upper Body ◽  
Whole Body ◽  
Hand Tools ◽  
Eucalypt Forest ◽  
Arm Work

In three-stage graded work tests we compared men's responses to laboratory step tests with their responses to building fireline with a rakehoe (McLeod tool) in dry eucalypt forest. The subjects were experienced firefighters and the scientific observers (novices at raking fireline) who carried out the investigation. At the average energy expenditure of raking fireline in bushfire suppression (655 W, oxygen uptake 1.9 1 min-1) the firefighters' heart rate (HR), pulmonary ventilation ((V)E), and rating of perceived exertion (RPE) were higher in raking than in stepping by 18 beats min-1, 13 1 min-1 and 0.5 units RPE respectively. At higher work rates the average difference in the response to raking and stepping decreased for HR (the opposite response to that found in laboratory studies of arm work), increased for (V) E, and did not change for RPE. Contrary to the usual finding for arm work, the firefighters' average maximal oxygen uptake (VO2max) was the same for raking and stepping, although the observers' raking (VO2max) was 10 % (P<0.01) less than their stepping (VO2max). These findings imply that firefighters rake mainly with their arms and upper body at normal work rates, but recruit additional trunk and leg muscles at higher work rates to achieve a 'whole-body' (VO2max) — which is greater than could be achieved with the arm work of normal raking and would thus lead to underestimates of strain and fatigue. Seventeen (50%) of the firefighters, but only one (8%) of the observers, had greater (VO2max) for raking than for stepping, suggesting that regular practice with hand tools had enhanced the firefighters' raking performance through local muscle training and improved technique.

scholarly journals Upper- vs. Lower-Body Exercise Performance in Female and Male Cross-Country Skiers

2021 ◽  
Vol 3 ◽  
Author(s):  
Linda Marie Hansen ◽  
Øyvind Sandbakk ◽  
Gertjan Ettema ◽  
Julia Kathrin Baumgart
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Physiological Responses ◽  
Peak Oxygen Uptake ◽  
Rating Of Perceived Exertion ◽  
Upper Body ◽  
Endurance Capacity ◽  
Lower Body ◽  
Exercise Modality ◽  
Cross Country

Purpose: To investigate the interaction between exercise modality (i.e., upper- and lower-body exercise) and sex in physiological responses and power output (PO) across the entire intensity spectrum (i.e., from low to maximal intensity).Methods: Ten male and 10 female cross-country (XC) skiers performed a stepwise incremental test to exhaustion consisting of 5 min stages with increasing workload employing upper-body poling (UP) and running (RUN) on two separate days. Mixed measures ANOVA were performed to investigate the interactions between exercise modalities (i.e., UP and RUN) and sex in physiological responses and PO across the entire exercise intensity spectrum.Results: The difference between UP and RUN (ΔUP−RUN), was not different in the female compared with the male XC skiers for peak oxygen uptake (18 ± 6 vs. 18 ± 6 mL·kg−1·min−1, p = 0.843) and peak PO (84 ± 18 vs. 91 ± 22 W, p = 0.207). At most given blood lactate and rating of perceived exertion values, ΔUP−RUN was larger in the male compared with the female skiers for oxygen uptake and PO, but these differences disappeared when the responses were expressed as % of the modality-specific peak.Conclusion: Modality-differences (i.e., ΔUP−RUN) in peak physiological responses and PO did not differ between the female and male XC skiers. This indicates that increased focus on upper-body strength and endurance training in female skiers in recent years may have closed the gap between upper- and lower-body endurance capacity compared with male XC skiers. In addition, no sex-related considerations need to be made when using relative physiological responses for intensity regulation within a specific exercise modality.

Project Aquarius 3. Effects of Work Rate on the Productivity, Energy Expenditure, and Physiological Responses of Men Building Fireline With a Rakehoe in Dry Eucalypt Forest

1997 ◽  
Vol 7 (2) ◽  
pp. 87 ◽  
Author(s):  
JR Brotherhood ◽  
GM Budd ◽  
AL Hendrie ◽  
SE Jeffery ◽  
FA Beasley ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Ventilatory Threshold ◽  
Pulmonary Ventilation ◽  
Work Load ◽  
Work Capacity ◽  
Work Rate ◽  
Eucalypt Forest ◽  
Stable Characteristic

Four crews of firefighters built fireline for 7 min periods (with intervening rests), without fire, at self-chosen 'slow', 'normal', and 'fast' rates in Australian eucalypt forests. Individuals differed twofold for energy expenditure (EE, measured as oxygen uptake by the Douglas bag technique) and relative work load (RWL, i.e % of maximum oxygen uptake), and threefold for productivity and efficiency (productivity per unit EE). They maintained their differences in all stages of the test and also while suppressing free-running wildland fires, showing that the work rate adopted was a stable characteristic of the individuals' work behaviour. The technique of raking fireline did not constrain EE but instead allowed firefighters to call upon their maximum work capacity for urgent tasks with no reduction in efficiency. EE, RWL, and heart rate increased linearly with productivity whereas perceived exertion and pulmonary ventilation increased curvilinearly, rising steeply at 'fast' work rates. We suggest that perceived exertion and the ventilatory threshold (the upper limit of comfortable breathing) provide the cues by which firefighters pace themselves at sustainable work rates that balance their fireline productivity against its physiological cost. The findings were highly consistent over four crews, three summers, and two regions and are thus generally applicable to bushfire suppression in southern Australia.

Validation of the OMNI-Cycle Scale of Perceived Exertion in the Elderly

2011 ◽  
Vol 19 (3) ◽  
pp. 214-224 ◽  
Author(s):  
Laura Guidetti ◽  
Antonio Sgadari ◽  
Cosme F. Buzzachera ◽  
Marianna Broccatelli ◽  
Alan C. Utter ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Construct Validity ◽  
Perceived Exertion ◽  
Pulmonary Ventilation ◽  
Cycle Ergometer ◽  
Rating Of Perceived Exertion ◽  
Elderly Men ◽  
Men And Women ◽  
Cycle Ergometer Exercise ◽  
Ergometer Exercise

This study examined the concurrent and construct validity of the OMNI-Cycle Rating of Perceived Exertion (RPE) Scale, using elderly men and women. Seventy-six participants performed a load-incremented cycle-ergometer exercise test. Concurrent validity was determined by correlating OMNI-RPE responses with oxygen uptake, relative peak oxygen uptake, pulmonary ventilation, heart rate, respiratory rate, and respiratory-exchange ratio during a load-incremented cycle-ergometer protocol. Construct validity was established by correlating RPE derived from the OMNI-Cycle Scale with RPE from the Borg (6–20) Scale. Multilevel, mixed linear-regression models indicated that OMNI-RPE distributed as a significant (p< .05) positive linear function (r= .81–.92) for all physiological measures. OMNI-RPE was positively (p< .01) and linearly related to Borg-RPE in elderly men (r= .97) and women (r= .96). This study demonstrates both concurrent and construct validity of the OMNI-Cycle RPE Scale. These findings support the use of this scaling metric with elderly men and women to estimate RPE during cycle-ergometer exercise.

scholarly journals Physiological responses and cycle characteristics during double-poling versus diagonal-stride roller-skiing in junior cross-country skiers

2021 ◽  
Author(s):  
Erik P. Andersson ◽  
Irina Hämberg ◽  
Paulo Cesar Do Nascimento Salvador ◽  
Kerry McGawley
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Double Poling ◽  
Cross Country

Abstract Purpose This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. Results No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L−1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ($$\dot{V}$$ V ˙ O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). Conclusion In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher $$\dot{V}$$ V ˙ O2peak values when using DS compared to DP.

scholarly journals Does Metabolic Rate Increase Linearly with Running Speed in all Distance Runners?

2017 ◽  
Vol 02 (01) ◽  
pp. E1-E8 ◽  
Author(s):  
Matthew Batliner ◽  
Shalaya Kipp ◽  
Alena Grabowski ◽  
Rodger Kram ◽  
William Byrnes
Keyword(s):  
Oxygen Uptake ◽  
Metabolic Rate ◽  
Perceived Exertion ◽  
Running Economy ◽  
Rating Of Perceived Exertion ◽  
Distance Runners ◽  
Cost Of Transport ◽  
Linear Relationships ◽  
Distance Running Performance ◽  
Elite Runners

AbstractRunning economy (oxygen uptake or metabolic rate for running at a submaximal speed) is one of the key determinants of distance running performance. Previous studies reported linear relationships between oxygen uptake or metabolic rate and speed, and an invariant cost of transport across speed. We quantified oxygen uptake, metabolic rate, and cost of transport in 10 average and 10 sub-elite runners. We increased treadmill speed by 0.45 m·s−1 from 1.78 m·s−1 (day 1) and 2.01 m·s−1 (day 2) during each subsequent 4-min stage until reaching a speed that elicited a rating of perceived exertion of 15. Average runners’ oxygen uptake and metabolic rate vs. speed relationships were best described by linear fits. In contrast, the sub-elite runners’ relationships were best described by increasing curvilinear fits. For the sub-elites, oxygen cost of transport and energy cost of transport increased by 12.8% and 9.6%, respectively, from 3.58 to 5.14 m·s−1. Our results indicate that it is not possible to accurately predict metabolic rates at race pace for sub-elite competitive runners from data collected at moderate submaximal running speeds (2.68–3.58 m·s−1). To do so, metabolic rate should be measured at speeds that approach competitive race pace and curvilinear fits should be used for extrapolation to race pace.

The efficacy of the self-paced V̇O2max test to measure maximal oxygen uptake in treadmill running

2013 ◽  
Vol 38 (12) ◽  
pp. 1211-1216 ◽  
Author(s):  
Alexis R. Mauger ◽  
Alan J. Metcalfe ◽  
Lee Taylor ◽  
Paul C. Castle
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
The Self ◽  
Rating Of Perceived Exertion ◽  
Treadmill Running ◽  
The Novel ◽  
Balanced Design ◽  
Graded Exercise Test ◽  
Graded Exercise

The novel self-paced, cycle-based maximal oxygen uptake (V̇O2max) test (SPV) has been shown to produce higher V̇O2max values than standard graded exercise test (GXT) protocols. This study sought to ascertain whether these observations would also be apparent in a self-paced, treadmill-based test design. Fourteen trained male runners performed a standard GXT on a motorised treadmill and a self-paced V̇O2max test on a nonmotorised treadmill in a counter-balanced design. The GXT included a plateau verification and was designed to last between 8 and 12 min. The self-paced test included 5 × 2 min stages and allowed participants to set their own running speed based on fixed increments in rating of perceived exertion. Significantly higher V̇O2max values (t[13] = 3.71, p = 0.003) were achieved in the self-paced test (64.4 ± 7.3 mL·kg−1·min−1) compared with the GXT (61.3 ± 7.3 mL·kg−1·min−1), and 13 of the 14 participants achieved the same or higher V̇O2max values in the self-paced test. Higher (p = 0.01) maximum heart rates were observed in the GXT (191 ± 10 beats·min−1 vs. 187 ± 7 beats·min−1), but no differences were observed in any other recorded variables. The self-paced V̇O2max test may provide a more valid means of measuring V̇O2max than the GXT and suggests that a V̇O2 plateau during a GXT does not always signify achievement of a definitive V̇O2max. These results provide further support that self-paced V̇O2max testing produces higher values for maximal oxygen uptake.

Hormonal, Physiological, and Physical Performance During Simulated Kickboxing Combat: Differences Between Winners and Losers

2016 ◽  
Vol 11 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Ibrahim Ouergui ◽  
Philip Davis ◽  
Nizar Houcine ◽  
Hamza Marzouki ◽  
Monia Zaouali ◽  
...  
Keyword(s):  
Test Performance ◽  
High Intensity ◽  
Perceived Exertion ◽  
National Level ◽  
Wingate Test ◽  
Rating Of Perceived Exertion ◽  
Upper Body ◽  
Before And After ◽  
Mental Abilities ◽  
Physical Responses

The aim of the current study was to investigate the hormonal, physiological, and physical responses of simulated kickboxing competition and evaluate if there was a difference between winners and losers. Twenty athletes of regional and national level participated in the study (mean ± SD age 21.3 ± 2.7 y, height 170.0 ± 5.0 cm). Hormone (cortisol, testosterone, growth hormone), blood lactate [La], and glucose concentrations, as well as upper-body Wingate test and countermovement-jump (CMJ) performances, were measured before and after combats. Heart rate (HR) was measured throughout rounds 1, 2, and 3 and rating of perceived exertion (RPE) was taken after each round. All combats were recorded and analyzed to determine the length of different activity phases (high-intensity, low-intensity, and referee pause) and the frequency of techniques. Hormones, glucose, [La], HR, and RPE increased (all P < .001) precombat to postcombat, while a decrease was observed for CMJ, Wingate test performance, body mass (all P < .001), and time of high-intensity activities (P = .005). There was no difference between winners and losers for hormonal, physiological, and physical variables (P > .05). However, winners executed more jab cross, total punches, roundhouse kicks, total kicks, and total attacking techniques (all P < .042) than losers. Kickboxing is an intermittent physically demanding sport that induces changes in the stress-related hormones soliciting the anaerobic lactic system. Training should be oriented to enhance kickboxers’ anaerobic lactic fitness and their ability to strike at a sufficient rate. Further investigation is needed to identify possible differences in tactical and mental abilities that offer some insight into what makes winners winners.

Chronic fatigue syndrome: new evidence for a central fatigue disorder

2003 ◽  
Vol 105 (2) ◽  
pp. 213-218 ◽  
Author(s):  
Evelina GEORGIADES ◽  
Wilhelmina M. H. BEHAN ◽  
Liam P. KILDUFF ◽  
Marios HADJICHARALAMBOUS ◽  
Eileen E. MACKIE ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chronic Fatigue Syndrome ◽  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Chronic Fatigue ◽  
Rating Of Perceived Exertion ◽  
Time Points ◽  
Fatigue Syndrome ◽  
Rate Limiting

Considerable evidence points towards a prominent role for central nervous system (CNS) mechanisms in the pathogenesis of chronic fatigue syndrome (CFS), a disorder characterized chiefly by persistent, often debilitating, fatigue. We wished to characterize circulating profiles of putative amino acid modulators of CNS 5-hydroxytryptamine (5-HT; serotoninergic) and dopaminergic function in CFS patients at rest, as well as during symptom-limited exercise and subsequent recovery. Groups of 12 CFS patients and 11 age- and sex-matched sedentary controls, with similar physical activity histories, underwent ramp-incremental exercise to the limit of tolerance. Plasma amino acid concentrations, oxygen uptake and ratings of perceived exertion were measured at rest, and during exercise and recovery. Peak oxygen uptake was significantly lower in the CFS patients compared with controls. Rating of perceived exertion in the patients was higher at all time points measured, including at rest, relative to controls. Levels of free tryptophan (free Trp), the rate-limiting 5-HT precursor, were significantly higher in CFS patients at exhaustion and during recovery, whereas concentrations of branched-chain amino acids (BCAA) and large neutral amino acids (LNAA) were lower in CFS patients at exhaustion, and for LNAA also during recovery. Consequently, the [free Trp]/[BCAA] and [free Trp]/[LNAA] ratios were significantly higher in CFS patients, except at rest. On the other hand, levels of tyrosine, the rate-limiting dopaminergic precursor, were significantly lower at all time points in the CFS patients. The significant differences observed in a number of key putative CNS 5-HT and dopaminergic modulators, coupled with the exacerbated perception of effort, provide further evidence for a potentially significant role for CNS mechanisms in the pathogenesis of CFS.

Higher Fat Oxidation in Running Than Cycling at the Same Exercise Intensities

2010 ◽  
Vol 20 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Benoit Capostagno ◽  
Andrew Bosch
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Fat Oxidation ◽  
Carbohydrate Oxidation ◽  
Rating Of Perceived Exertion ◽  
Plasma Lactate ◽  
Maximum Heart Rate ◽  
Maximum Workload

This study examined the differences in fat and carbohydrate oxidation during running and cycling at the same relative exercise intensities, with intensity determined in a number of ways. Specifically, exercise intensity was expressed as a percentage of maximum workload (WLmax), maximum oxygen uptake (%VO2max), and maximum heart rate (%HRmax) and as rating of perceived exertion (RPE). Ten male triathletes performed maximal running and cycling trials and subsequently exercised at 60%, 65%, 70%, 75%, and 80% of their WLmax. VO2, HR, RPE, and plasma lactate concentrations were measured during all submaximal trials. Fat and carbohydrate oxidation were calculated from VO2 and VCO2 data. A 2-way ANOVA for repeated measures was used to determine any statistically significant differences between exercise modes. Fat oxidation was shown to be significantly higher in running than in cycling at the same relative intensities expressed as either %WLmax or %VO2max. Neither were there any significant differences in VO2max and HRmax between the 2 exercise modes, nor in submaximal VO2 or RPE between the exercise modes at the same %WLmax. However, heart rate and plasma lactate concentrations were significantly higher when cycling at 60% and 65% and 65–80%WLmax, respectively. In conclusion, fat oxidation is significantly higher during running than during cycling at the same relative intensity expressed as either %WLmax or %VO2max.

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