Economy Of Movement Research Articles

Immune Responses To An Acute Maximal Exercise Changes During A Training Cycle In Swimming

In endurance sports, cycles of high training volume are implemented in order to optimize aerobic and movement economy adaptations. This leads to transient imbalances between training loads and recovery contributing to the onset of fatigue and sometimes illness in highly trained athletes. The well-established interdependence between substrate depletion, hormonal and immune functions elicits usually a immunodepression state as response to hard training periods. PURPOSE: To evaluate the effects of two subsequent training cycles of different load quantitative and intensity characteristics on the response of systemic and mucosal immunity to a maximal swimming bout. METHODS: 6 well-trained male swimmers (18±2.2 yrs; 177±6.3 cm; 67±5.3 Kg) performed an incremental maximal step test (7×200 m front crawl) in 3 moments of the season: M1 - after a recovery microcycle, M2 - after a 5 week period of aerobic overload (volume increased by 20%) and M3 - after 8 weeks of progressively decreasing volume and higher intensities. Blood and saliva samples were collected before (6:30 a.m.) and 5 min after, for the determination of leukocyte and total lymphocyte and subpopulations (CD3+, CD4+, CD8+, CD19+ and CD16+) counts by flow cytometry; serum immunoglobulin A (IgA) concentration by cytometric bead array and salivary IgA (s-IgA) concentrations by ELISA. s-IgA secretory rate (sr-IgA) was calculated from s-IgA values. ANOVA for repeated measures was used for the assessment of training effect. The level of significance was set at p<.05. RESULTS: At rest, CD16+ (NK) cells and IgA decreased significantly from M1 to M2, recovering to initial levels at M3. The acute response (% change) of total lymphocytes, CD3+, CD4+ and CD16+ remained stable from M1 to M2 but was elevated at M3, contrarily to the CD4+/CD8+ ratio, which decreased significantly in M3. CONCLUSIONS: In spite of some signs of impaired immune capacity after the hard training period in what concerns the rest values, values after maximal exercise, even of CD16+ cells, showed high systemic responsiveness. Training load volume seems to be the main determinant of immune changes, with overall recovery of initial levels at M3. During this training cycle it was observed a stimulation of systemic immunity and the maintenance of mucosal immunity.

Neuromuscular Economy, Strength, and Endurance in Healthy Elderly Men

Declines in muscular strength resulting from reduced neural activity may influence the reduction in aerobic capacity in older men. However, there has been little investigation into the relationship between muscular strength and economy of movement during aerobic exercise in elderly subjects. Thus, the purpose of this study was to investigate the possible relationship between strength, aerobic performance, and neuromuscular economy in older men. Twenty-eight aged men (65 ± 4 years old) were evaluated in dynamic (1 repetition maximum test), isometric strength (maximal voluntary contraction), and rate of force development. Peak oxygen uptake, maximal workload, and ventilatory threshold were determined during a ramp protocol on a cycle ergometer. Throughout the same protocol, the neuromuscular economy (electromyographic signal) of the vastus lateralis was measured. Significant correlations were found between muscular strength, cardiorespiratory fitness, and neuromuscular economy (r = 0.43-0.64, p < 0.05). Our results suggest that cardiorespiratory capacity and economy of movement are associated with muscular strength during aging.

The political economy of movement and gesture in Cairo

Based on fieldwork in Cairo, this article shows how analysis of bodily practice and of political economy – two fields that anthropologists have treated as completely separate – intersect in important ways. I provide conceptual tools to solve a common ethnographic dilemma: how can members of a group with no official status, no distinguishing marks of ethnicity, religious difference, race, recognize others who share that identity? I argue that the embodied practice in which the historically constituted identity of sha‘abi people in Cairo is evinced lies in the realm of gesture, while the embodied practice through which status as a pious Muslim is evinced lies in the realm of significant symbol. I further argue that gestural resources of poor people of Cairo can usefully be analysed as a ‘semiotic commons’ and ‘collective good’ in the political economy of Egypt. Resume Sur la base d’un travail de terrain au Caire, l’auteure met en lumiere des recoupements importants entre l’analyse des pratiques corporelles et celle de l’economie politique, deux domaines que les anthropologues ont separes. Elle fournit des outils conceptuels visant a resoudre un dilemme ethnographique frequent : comment les membres d’un groupe ne disposant d’aucun statut officiel, d’aucune marque distinctive d’appartenance ethnique, de difference religieuse ou de race, reconnaissent-ils ceux qui partagent leur identite. L’auteure affirme que la pratique incorporee dans laquelle s’inscrit l’identite, constituee historiquement, des sha’abi cairotes est de l’ordre du geste, tandis que la pratique incorporee marquant le statut de musulman pieux est de l’ordre du symbole signifiant. Elle affirme en outre que les ressources gestuelles des populations pauvres du Caire peuvent etre analysees utilement comme des « communs semiotiques » et comme un « bien collectif » dans l’economie politique egyptienne.

Differences in hand movements and task completion times between laparoscopic, robotically assisted, and open surgery: an in vitro study.

Surgical dexterity depends on economy and precision of movements, and this can be objectively measured using electromagnetic motion analysis. We have assessed the differences in hand movements and task completion times between open, laparoscopic and robotically assisted surgery during an exercise performed in vitro. A standard surgical exercise was performed using open, standard laparoscopic (SL) and robotically assisted laparoscopic (RAL) approaches. The total duration of the exercise was studied along with the number and duration of movements required to complete the exercise in each surgical modality. The time taken to complete the exercise was significantly longer in both the SL and RAL approaches when compared to the open route. However, it was found that RAL had significantly decreased number of movements (mean difference=24 movements, P<0.006) but a longer duration of each movement when compared to SL (mean difference=0.13s, P<0.001). This study shows objectively that the exercise took longer to complete using the RAL approach than the standard open approach. However, RAL had more purposeful movements and required fewer movements to complete the exercise compared to SL.

At the Mall With Children: Group Size and Pedestrian Economy of Movement

The study of pedestrian locomotion in public environments includes both velocity and trajectory of movement. Within public settings such as shopping malls, pedestrians display economy of movement by minimizing the distance (trajectory) walked to arrive at a destination (Bitgood &amp; Dukes, 2006). Although groups of pedestrians have been found to walk more slowly than individuals (Finnis &amp; Walton, 2008), there has been little systematic investigation of how the size of a group and the presence of accompanying children independently affect pedestrian trajectory and velocity. Five naturalistic observational studies with 1,050 observations were conducted at an enclosed retail shopping mall. Neither the size of groups nor the number of children had a significant effect on trajectory of movement. However, both group size and number of children independently predicted pedestrian velocity. Results have implications for predictions of pedestrian facility throughput.

Retention of laparoscopic procedural skills acquired on a virtual-reality surgical trainer

Virtual-reality (VR) simulator training has been shown to improve surgical performance in laparoscopic procedures in the operating room. We have, in a randomised controlled trial, demonstrated transferability to real operations. The validity of the LapSim virtual-reality simulator as an assessment tool has been demonstrated in several reports. However, an unanswered question regarding simulator training is the durability, or retention, of skills acquired during simulator training. The aim of the present study is to assess the retention of skills acquired using the LapSim VR simulator, 6 and 18 months after an initial training course. The investigation was designed as a 6- and 18-month follow-up on a cohort of participants who earlier participated in a skills training programme on the LapSim VR. The follow-up cohort consisted of trainees and senior consultants allocated to two groups: (1) novices (experience < 5 procedures, n = 9) and (2) experts (experience > 200 procedures during the past 3 years, n = 10). Each participant performed ten sessions. Assessment of skills was based on time, economy of movement and the error parameter "bleeding". The novice group were re-tested after 6 and 18 months, whereas the expert group were only retested once, after 6 months. None of the novices performed laparoscopic surgery in the follow-up period. The experts continued their daily work with laparoscopic surgery. Novices showed retention of skills after 6 months. After 18 months, novices' laparoscopic skills had returned to the pre-training level. This indicates that laparoscopic skills seemed to deteriorate in the period between 6 and 18 months without training. Experts showed consistent performance over time. This information can be included when planning training curricula in minimal invasive surgery.

Performance on a Virtual Reality Angled Laparoscope Task Correlates with Spatial Ability of Trainees

The aim of the present study was to investigate whether trainees' performance on a virtual reality angled laparoscope navigation task correlates with scores obtained on a validated conventional test of spatial ability. 56 participants of a surgery workshop performed an angled laparoscope navigation task on the Xitact LS 500 virtual reality Simulator. Performance parameters were correlated with the score of a validated paper-and-pencil test of spatial ability. Performance at the conventional spatial ability test significantly correlated with performance at the virtual reality task for overall task score (p < 0.001), task completion time (p < 0.001) and economy of movement (p = 0.035), not for endoscope travel speed (p = 0.947). In conclusion, trainees' performance in a standardized virtual reality camera navigation task correlates with their innate spatial ability. This VR session holds potential to serve as an assessment tool for trainees.

How changing the focus of attention affects performance, kinematics, and electromyography in dart throwing

Research has found an advantage for an external focus of attention in motor control and learning; instructing subjects to focus on the effects of their actions, rather than on body movements, can improve performance during training and retention testing. Previous research has mostly concentrated on movement outcomes, not on the quality of the movement itself. Thus, this study combined surface electromyography (EMG) with motion analysis and outcome measures in a dart throwing task, making this the first study that includes a comprehensive analysis of changes in motor performance as a function of attentional focus. An external focus of attention led to better performance (less absolute error), decreased preparation time between throws, and reduced EMG activity in the triceps brachii. There was also some evidence of increased variability for kinematic measures of the shoulder joint under an external focus relative to an internal focus. These results suggest improved movement economy with an external focus of attention.

The Effect of Practice and Chronic Ankle Instability on Intralimb Coordination and Movement Economy

The Effect of Practice and Chronic Ankle Instability on Intralimb Coordination and Movement Economy

Thermoregulatory Responses To Racewalking Vs. Running In A Hot Environment

Racewalking at speeds beyond 9 km/h results in higher energy expenditure than running at the same speed. We hypothesize that if racewalking takes place in a hot environment, its reduced economy of movement, may lead to larger body heat accumulation than when running at similar speed. Alternatively, the difference in movement pattern between walking and running (less strides but more forceful) may affect the mechanoreceptor signals that influence heat dissipation (i.e., sweating and skin blood flow). PURPOSE: To determine if in a hot environment racewalking increases core temperature above the levels observed when running at the same speed. To study if at the same rate of heat production, exercise mode (walking vs. running) affects heat dissipation and accumulation. METHODS: Nine competitive racewalkers (22 ± 5.1 yrs; 58 ± 5 mL · kg · min-1 of VO2max and 58 ± 9 kg of body weight) exercised during 60 min in a hot-dry environment (30.1 ± 1.4 °C; 33 ± 8 % relative humidity; 2.4 m · s-1 air speed) on three separated occasions: i) Walking (WALK) at a velocity just below lactate threshold (i.e., 11 km · h-1, ii) running at the same WALK velocity (RUN≈VEL) and, iii) running at a velocity which elicited a similar VO2 than when walking (i.e., 12.8 km · h-1; RUN≈VO2). Energy expenditure, intestinal temperature (TINT), skin temperature (TSK), heart rate, whole body sweat rate and skin blood flow (SKBF) were measured during exercise. Data were analyzed using single and repeated measures ANOVA. RESULTS: Pre-exercise body weight, hemoglobin concentration and urine specific gravity (USG) were not different before each trial evidencing similar initial hydration status. Energy expenditure was similar during WALK and RUN≈VO2 but lower during RUN≈VEL. Accordingly, final TINT was similar during WALK and RUN≈VO2 and both were higher than during RUN≈VEL (39.2 and 39.0 vs. 38.4 °C, respectively; P < 0.05). Final heart rate was higher during WALK and RUN≈VO2 than during RUN≈VEL (179 and 181 vs. 159 beats per minute, respectively; P < 0.05). However, sweat rate, TSK and SKBF were not different among trials. CONCLUSIONS: In a hot environment, racewalking at similar velocity than running, results in higher heat accumulation. However, when energy expenditure is matched, exercise mode (walk vs. run) has not measurable impact on heat accumulation or dissipation.

A computerized assessment to compare the impact of standard, stereoscopic, and high-definition laparoscopic monitor displays on surgical technique

Surgeons performing laparoscopic surgery have strong biases regarding the quality and nature of the laparoscopic video monitor display. In a comparative study, we used a unique computerized sensing and analysis system to evaluate the various types of monitors employed in laparoscopic surgery. We compared the impact of different types of monitor displays on an individual's performance of a laparoscopic training task which required the subject to move the instrument to a set of targets. Participants (varying from no laparoscopic experience to board-certified surgeons) were asked to perform the assigned task while using all three display systems, which were randomly assigned: a conventional laparoscopic monitor system (2D), a high-definition monitor system (HD), and a stereoscopic display (3D). The effects of monitor system on various performance parameters (total time consumed to finish the task, average speed, and movement economy) were analyzed by computer. Each of the subjects filled out a subjective questionnaire at the end of their training session. A total of 27 participants completed our study. Performance with the HD monitor was significantly slower than with either the 3D or 2D monitor (p < 0.0001). Movement economy with the HD monitor was significantly reduced compared with the 3D (p < 0.0004) or 2D (p < 0.0001) monitor. In terms of average time required to complete the task, performance with the 3D monitor was significantly faster than with the HD (p < 0.0001) or 2D (p < 0.0086) monitor. However, the HD system was the overwhelming favorite according to subjective evaluation. Computerized sensing and analysis is capable of quantitatively assessing the seemingly minor effect of monitor display on surgical training performance. The study demonstrates that, while users expressed a decided preference for HD systems, actual quantitative analysis indicates that HD monitors offer no statistically significant advantage and may even worsen performance compared with standard 2D or 3D laparoscopic monitors.

Psychomotor control in a virtual laparoscopic surgery training environment: gaze control parameters differentiate novices from experts

BackgroundSurgical simulation is increasingly used to facilitate the adoption of technical skills during surgical training. This study sought to determine if gaze control parameters could differentiate between the visual control of experienced and novice operators performing an eye-hand coordination task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Typically adopted hand movement metrics reflect only one half of the eye-hand coordination relationship; therefore, little is known about how hand movements are guided and controlled by vision.MethodsA total of 14 right-handed surgeons were categorised as being either experienced (having led more than 70 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The eight experienced and six novice surgeons completed the eye-hand coordination task from the LAP Mentor basic skills package while wearing a gaze registration system. A variety of performance, movement, and gaze parameters were recorded and compared between groups.ResultsThe experienced surgeons completed the task significantly more quickly than the novices, but only the economy of movement of the left tool differentiated skill level from the LAP Mentor parameters. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools.ConclusionThe findings of the study provide support for the utility of assessing strategic gaze behaviour to better understand the way in which surgeons utilise visual information to plan and control tool movements in a virtual reality laparoscopic environment. It is hoped that by better understanding the limitations of the psychomotor system, effective gaze training programs may be developed.

A tale of two trainers: virtual reality versus a video trainer for acquisition of basic laparoscopic skills

Background This study aimed to assess the transferability of basic laparoscopic skills between a virtual reality simulator (MIST-VR) and a video trainer box (D-Box). Methods Forty-six medical students were randomized into 2 groups, training on MIST-VR or D-Box. After training with one modality, a crossover assessment on the other was performed. Results When tested on MIST-VR, the MIST-VR group showed significantly shorter time (90.3 seconds vs 188.6 seconds, P <.001), better economy of movements (4.40 vs 7.50, P <.001), and lower score (224.7 vs 527.0, P <.001). However, when assessed on the D-Box, there was no difference between the groups for time (402.0 seconds vs 325.6 seconds, P = .152), total hand movements (THC) (289 vs 262, P = .792), or total path length (TPL) (34.9 m vs 34.6 m, P = .388). Conclusion Both simulators provide significant improvement in performance. Our results indicate that skills learned on the MIST-VR are transferable to the D-Box, but the opposite cannot be demonstrated.

The Role of Haptic Feedback in Laparoscopic Training Using the LapMentor II

Laparoscopic surgery has become the standard of care for many surgical diseases. Haptic (tactile) feedback (HFB) is considered an important component of laparoscopic surgery. Virtual reality simulation (VRS) is an alternative method to teach surgical skills to surgeons in training. Newer VRS trainers such as the Simbionix Lap Mentor II provide significantly improved tactile feedback. However, VRSs are expensive and adding HFB software adds an estimated cost of $30,000 to the commercial price. The HFB provided by the Lap Mentor II has not been validated by an independent party. We used the Simbionix Lap Mentor II in this study to demonstrate the effect of adding an HFB mechanism in the VRS trainer. The study was approved by the University of Cincinnati Institutional Review Board. Twenty laparoscopically novice medical students were enrolled. Each student was asked to perform three different tasks on the Lap Mentor II and repeat each one five times. The chosen tasks demanded significant amount of traction and counter traction. The first task was to pull leaking tubes enough and clip them. The second task was stretching a jelly plate enough to see its attachments to the floor and cut these attachments. In the third task, the trainee had to separate the gallbladder from its bed on the liver. The students were randomized into two groups to perform the tasks with and without HFB. We used accuracy, speed, and economy of movement as scales to compare the performance between the two groups. The participants also completed a simple questionnaire that highlighted age, sex, and experiences in videogame usage. The two groups were comparable in age, sex, and videogame playing. No differences in the accuracy, the economy, and the speed of hand movement were noticed. In fact, adding HFB to the Lap Mentor II simulator did not contribute to any improvement in the performance of the trainees. Interestingly, we found that videogame expert players tend to have faster and more economic motion in their dominant hands. However, the performance accuracy was not significantly affected. The presence of HFB has less effect than it thought to be on the performance of the novice trainees. This may suggest that better HFB is still needed. However, there may be visual compensation for the lack of haptics. Playing videogames has a positive impact on economy, and the speed of the dominant had motion without affecting its accuracy. Further research is needed to clarify the value of haptics to the expert surgeon and compare it to the new trainees.

A comparison of laparoscopic and robotic assisted suturing performance by experts and novices

Surgical robotics has been promoted as an enabling technology. This study tests the hypothesis that use of the robotic surgical system can significantly improve technical ability by comparing the performance of both experts and novices on a complex laparoscopic task and a robotically assisted task. Laparoscopic experts (LE) with substantial laparoscopic and robotic experience (n = 9) and laparoscopic novices (LN) (n = 20) without any robotic experience performed sequentially 10 trials of a suturing task using either robotic or standard laparoscopic instrumentation fitted to the ProMIS surgical simulator. Objective performance metrics provided by ProMIS (total task time, instrument pathlength, and smoothness) and an assessment of learning curves were analyzed. Compared with LNs, the LEs demonstrated significantly better performance on all assessment measures. Within the LE group, there was no difference in smoothness (328 +/- 159 vs 355 +/- 174; P = .09) between robot-assisted and standard laparoscopic tasks. An improvement was noted in total task time (113 +/- 41 vs 132 +/- 55 sec; P < .05) and instrument pathlengths (371 +/- 163 vs 645 +/- 269 cm; P < .05) when using the robot. This advantage in terms of total task time, however, was lost among the LEs by the last 3 trials (114 +/- 40 vs 118 +/- 49 s; P = .84), while instrument pathlength remained better consistently throughout all the trials. For the LNs, performance was significantly better in the robotic trials on all 3 measures throughout all the trials. The ProMIS surgical simulator was able to distinguish between skill levels (expert versus novice) on robotic suturing tasks, suggesting that the ProMIS is a valid tool for measuring skill in robot-assisted surgery. For all the ProMIS metrics, novices demonstrated consistently better performance on a suturing task using robotics as compared to a standard laparoscopic setup. This effect was less evident for experts who demonstrated improvements only in their economy of movement (pathlength), but not in the speed or smoothness of performance. Robotics eliminated the early learning curve for novices, which was present when they used standard laparoscopic tools. Overall, this study suggests that, when performing complex tasks such as knot tying, surgical robotics is most useful for inexperienced laparoscopists who experience an early and persistent enabling effect. For experts, robotics is most useful for improving economy of motion, which may have implications for the highly complex procedures in limited workspaces (eg, prostatectomy).

Aging and inactivity—capitalizing on the protective effect of planned physical activity in old age

AbstractThe paper discusses two parallel biocultural trends—aging and inactivity. The principle of economy in movement in modern society versus the dependency of human beings on movement for their development and health is described. The results of inactivity are sometimes mistakenly considered irreversible losses caused by aging, but in actual fact, inactivity accelerates the irreversible losses caused by the aging process. The paper then describes the contribution of physical activity in terms of increasing positive aspects or decreasing risks: increasing life expectancy or decreasing risk of mortality, increasing cardiovascular fitness or decreasing risk of cardiovascular disease, increasing muscle mass or decreasing falls and instability, improving cognitive performance or reducing cognitive decline and neurological disorders, and improving well-being or reducing depression. The optimal dose of physical activity is then described, followed by recommendations for further research on mechanisms determining physical activity behavior.

Climate Change and the Contemporary Evolution of Foodways

Climate Change and the Contemporary Evolution of Foodways

The Role of Simulator Promis2 in Learning Laparoscopic Skill

Laparoscopic surgery is unique and complex in nature, so the training is necessary before proceeding to operation room. Many computer aided simulators have been developed for the purpose. Our objective is to assess the improvement of basic laparoscopic skills after training in simulator. The fifth year medical students underwent training of three laparoscopic skills using Promis2 simulator twice weekly for 4-6 weeks. The skills are laparoscopic orientation, target pointing and objects transferring. Time, path length of instruments and economy of movements were recorded. The comparisons were made for these parameters between session first and the last using a Mann-Whitney U test. Ten volunteers completed the exercises in less time (186.3 +/- 55.4 seconds) than the first exercise (215.7 +/- 57.4 seconds) (P=0.0027). Both the right and left hand instrument path lengths were also improved from 4425.8 +/- 1284.3 mm in the first exercise to 3925.3 +/- 1313.6 mm in the last exercise in the left side (P=0.0219) and likewise from 4273.8 +/- 1859.4 mm to 3831.3 +/- 1717.4 mm in the right side (P=0.0027). Economy of the movement in the left handed instrument improved from 1114.4 +/- 453.5 mm in the first exercise to 966.8 +/- 411.1 mm in the last (P=0.0443) and in the right handed instrument from 845 +/- 398.8 mm to 771.4 +/- 370.5 mm according to the software of Promis2 simulator (P >0.005). Training in Promis2 simulator improves the basic laparoscopic skills. The candidates become consistently faster with shorter path lengths and had smoother instruments movements. They also became significantly more consistent in their performance.

Comparison of energy expenditure, economy, and pedometer counts between normal weight and overweight or obese women during a walking and jogging activity

This study compared energy expenditure (EE), economy of movement, and pedometer counts between normal weight and overweight or obese women during a treadmill walking and jogging activity. Participants were 13 normal weight (BMI 22.2 +/- 2.0 kg m(-2)) and 13 overweight or obese (BMI 27.2 +/- 2.1 kg m(-2)) women and all were non-smokers, not regularly active, and able to run 1.609 km continuously at 2.23 m s(-1). Each participant reported to the laboratory on three separate days within a 1-week period. During the first visit, tests for resting metabolic rate via indirect calorimetry, anthropometric measures, and VO(2)max were completed. On the subsequent two visits, participants were randomized to perform either a 1.609-km walk at 1.34 m s(-1) or a 1.609-km jog at 2.23 m s(-1). During each physical activity trial, all participants wore a pedometer to assess steps taken. EE during the 1.609-km walk was 280 +/- 29 kJ for the normal weight and 356 +/- 42 kJ for the overweight/obese women and during the 1.609-km jog was 393 +/- 46 kJ for the normal weight and 490 +/- 59 kJ for the overweight/obese women. In both trials, EE was statistically greater in the overweight/obese women. Economy of movement was not statistically different between the normal weight and overweight/obese women during the walk or jog. In both groups, pedometer counts were lower during the jog than the walk (P < 0.05). These data indicate significant differences in EE between normal weight and overweight/obese women during both a walking and jogging activity.

Short-duration Quercetin Supplementation Does Not Alter Substrate Utilization, Cycling Economy, Or Rpe In Untrained Men

Quercetin is a naturally-occurring dietary flavonoid found in fruits and vegetables. Quercetin feedings for 7 d in sedentary mice have increased skeletal muscle mitochondrial enzyme activity by 20-30%. Increased mitochondrial enzyme activity might alter movement economy and substrate utilization during submaximal exercise. In in vitro tests, quercetin has been shown to be an adenosine A-1 receptor antagonist and, thus, may have analgesic effects that alter perception of effort. Dietary quercetin supplementation for 3-6 wk has not increased muscle mitochondrial enzyme activity, substrate utilization, movement economy, or RPE in trained cyclists, but the effects of quercetin supplementation in untrained humans are unknown. PURPOSE: To investigate the effects of short-duration quercetin supplementation on substrate utilization, movement economy, and RPE measured during submaximal cycling in untrained men. METHODS: Using a double-blind, pretest-posttest, control-group design, 30 recreationally-active, but not endurance-trained, young men were randomly assigned to Quercetin (Q) and Placebo (P) groups. Measurements during min 58-60 of submaximal cycling at 50% VO2max were performed before and after 9-16 d of supplementation with 1 g/d of quercetin in a fruit punch beverage or a placebo beverage. RESULTS: Pretest-to-posttest changes in respiratory quotient (Q: 0.89 ± 0.03 vs 0.92 ± 0.03; P: 0.89 ± 0.03 vs 0.90 ± 0.04), plasma glucose (Q: 4.5 ± 1.0 vs 4.7 ± 1.2 mmol/L; P: 4.8 ± 0.9 vs 4.8 ± 0.6 mmol/L), plasma non-esterified fatty acids (Q: 0.52 ± 0.19 vs 0.41 ± 0.13 mmol/L; P: 0.42 ± 0.18 vs 0.49 ± 0.19 mmol/L), plasma glycerol (Q: 0.09 ± 0.12 vs 0.06 ± 0.06 mmol/L; P: 0.07 ± 0.06 vs 0.07 ± 0.07 mmol/L), and beta hydroxybuterate (Q: 0.13 ± 0.10 vs 0.09 ± 0.03 mmol/L; P: 0.08 ± 0.04 vs 0.09 ± 0.05 mmol/L) were not significantly different (p > 0.05) in Q and P. Changes in VO2 (Q: 21.7 ± 4.2 vs 20.3 ± 3.3 ml/kg·min; P: 19.9 ± 2.8 vs 19.6 ± 3.4 ml/kg·min) and RPE (Q: 12.7 ± 1.4 vs 11.8 ± 1.6; P: 11.2 ± 2.7 vs 11.4 ± 2.4) also were not significant (p > 0.05). CONCLUSIONS: Dietary quercetin supplementation with 1 g/d for 9-16 d does not alter substrate utilization, cycling economy, or RPE in untrained men. Supported by the Beverage Institute for Health and Wellness, The Coca-Cola Company.