1 |
Custo energético durante a prática do Kendō e proposição de protocolo específico para avaliação da aptidão aeróbia em praticantes / Energy expenditure during Kendō practice and a specific protocol as proposal to the assessment of practitioner’s aerobic conditionSancassani, Andrei [UNESP] 06 April 2016 (has links)
Submitted by Andrei Sancassani null (andreisanca@hotmail.com) on 2016-05-09T12:37:09Z
No. of bitstreams: 1
Dissertação-4.pdf: 1004721 bytes, checksum: 5e21e3f1719813a43afcc58ade609212 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-12T13:01:48Z (GMT) No. of bitstreams: 1
sancassani_a_me_rcla.pdf: 1004721 bytes, checksum: 5e21e3f1719813a43afcc58ade609212 (MD5) / Made available in DSpace on 2016-05-12T13:01:48Z (GMT). No. of bitstreams: 1
sancassani_a_me_rcla.pdf: 1004721 bytes, checksum: 5e21e3f1719813a43afcc58ade609212 (MD5)
Previous issue date: 2016-04-06 / Enquanto luta, o Kendō apresenta movimentos dinâmicos e estáticos, com manejo da espada em diferentes planos e amplitudes articulares, além do deslocamento vertical e horizontal do corpo. Este estudo teve por objetivo quantificar o custo energético (Ė) durante a prática do Kendō, bem como analisar a aptidão aeróbia de seus praticantes (consumo máximo de oxigênio (V̇O2max), limiar de permuta gasosa (LPG) e ponto de compensação respiratória (PCR)) e propor um protocolo progressivo máximo com técnicas do Kendō para a avaliação específica da aptidão aeróbia. Dez participantes homens (29,0 ± 7,6 anos, 82,0 ± 14,2 kg, 174,4 ± 7,5 cm) foram submetidos à (1) avaliação da composição corporal pelo DXA, (2) teste progressivo em esteira para avaliação cardiorrespiratória, (3) protocolo de desempenho: 11 exercícios de aquecimento e 31 de waza, aplicando técnicas de Kendō e (4) protocolo específico para o Kendō. Parâmetros ventilatórios foram amostrados respiração-a-respiração, usando uma unidade portátil (K4b2, COSMED®). O Ė (kcal×min-1) foi obtido pela equação: Ė = 3,941 × V̇O2 + 1,106 × V̇CO2. Para cada fase do protocolo (aquecimento e waza) foram considerados: ĖPico (ĖPicoAquec e ĖPicoWaza, em kcal×min-1), ĖMédia (ĖMédiaAquec e ĖMédiaWaza, em kcal×min-1) e ĖTotal (ĖTotalAquec, ĖTotalWaza e ĖTotalProt, em kcal). A transformação em equivalente metabólico (MET) foi realizada com o emprego da constante 4.184 (kJ×kg-1×h-1) a partir do V̇O2 de repouso (avaliado na posição sentada durante 10 minutos). A quantidade (gramas) e taxa (gramas∙min-1) de oxidação de carboidratos (CHO) e gorduras (FAT) foi determinada por: CHO = 4,585 V̇CO2 – 3,226 V̇O2 e FAT = 1,695 V̇O2 – 1,701 V̇CO2. O coeficiente de Pearson analisou as correlações entre as variáveis do custo energético e da composição regional e corporal. Em todas as análises adotou-se ≤ 0,05. Os valores de ĖTotal foram: 76,2 ± 13,2 kcal (ĖTotalAquec) e 142,2 ± 26,5 kcal (ĖTotalWaza). Os valores de pico foram: 13,5 ± 2,7 kcal×min-1 (ĖPicoAquec) e 14,3 ± 2,9 kcal×min-1 (ĖPicoWaza). Em METs, os valores alcançaram picos de 6,9 ± 1,4 e 7,7 ± 1,8 kJ×kg-1×h-1 durante a execução do aquecimento e waza, respectivamente. As quantidades de CHO e FAT utilizadas foram 21,5 7,4 gramas e 2,0 1,1 gramas (aquecimento) e 52,0 6,4 gramas e 0,1 0,2 gramas (waza). A massa total e área regional e corporal não diferem quanto à influência sobre as variáveis de Ė e oxidação de substratos, porém a massa isenta de gordura regional (MIG) é mais influente sobre as variáveis de Ė, quando comparada à MIG corporal. Assim, a demanda energética durante a execução das técnicas do Kendō está associada à área e à quantidade de tecido regional metabolicamente ativo. / As fighting, the Kendō is a combination of dynamic and static movements handling the sword in different plans and range of motion, as well as vertical and horizontal body displacement. This study aimed to quantify the energy cost during the practice of Kendō, and also analyze the aerobic level of the practitioners (maximal oxygen consumption (V̇ O2max), gas exchange threshold (GET) and respiratory compensation point (RCP)), and finally propose a progressive protocol from Kendō techniques to the specific assessment of aerobic condition. Ten male participants (29.0 ± 7.6 years, 82.0 ± 14.2 kg, 174.4 ± 7.5 cm) were underwent (1) assessing body composition by DXA, (2) progressive treadmill test for cardiac evaluation, (3) Performance protocol: 11 warm-up exercises and 31 waza, applying techniques Kendō, and (4) specific Kendō protocol. Ventilatory parameters were sampled breath-by-breath using a portable unit (K4b2 , Cosmed). The Ė (kcal×min-1 ) was obtained from: Ė = 3.941 × 1.106 × V̇ O2 + V̇ CO2. For each phase of the protocol (warm-up and waza) were considered: ĖPeak (ĖPeakWarm and ĖPeakWaza, in kcal×min-1 ), ĖMean (ĖMeanWarm and ĖMeanWaza, in kcal×min-1 ), and ĖTotal (ĖTotalWarm, ĖTotalWaza and ĖTotalProt, in kcal). The metabolic equivalent (MET) was obtained by the constant 4.184 (kJ× g-1 ×h-1 ) from the rest V̇ O2 (measured in sited position for 10 minutes). The amount (grams) and rate (grams×min-1 ) for carbohydrate (CHO) and fat (FAT) oxidation were measured from CHO = 4,585 V̇ CO2 – 3,226 V̇ O2 e FAT = 1,695 V̇ O2 – 1,701 V̇ CO2. The Pearson’s coefficient analyzed the correlation between the variables of energy cost and regional/whole body composition. The level of significance was set at ≤ 0.05. The values for ĖTotal were: 76.2 ± 13.2 kcal (ĖTotalAquec) and 142.2 ± 26.5 kcal (ĖTotalWaza). The peak values were: 13.5 ± 2.7 kcal×min-1 (ĖPeakWarm) and 14.3 ± 2.9 kcal×min-1 (ĖPeakWaza). The MET values reached peaks at 6.9 ± 1.4 and 7.7 ± 1.8 kJ×kg-1 ×h-1 during the warm-up and waza, respectively. The amount of CHO and FAT oxidized were 21.5 7.4 grams and 2.0 1.1 grams (warm-up), and 52.0 6.4 grams and 0.1 0.2 grams (Waza). The regional and whole-body total mass and area had no different for the influence on the expenditure of Ė and substrate, although regional FFM exerted greater influence on Ė variables than whole-body FFM have presented. Thus, the energy demand during Kendō performance is related to the area and the amount of regional tissue metabolically active.
|
2 |
Prognostisk prestanda hos arbetsprov jämfört med myokardscintigrafi hos patienter med kranskärlsjukdom / The prognostic performance in exercise treadmill test compared to myocardial perfusion imaging (MPI) in coronary artery disease (CAD) patientsIngabire, Aline, Hassanzadeh, Zahra January 2020 (has links)
Kranskärlssjukdom (CAD) är den ledande dödsorsaken. Sjukdomen startar med plackbildning i ett eller flera kranskärl, vilket kan leda till bröstsmärta samt andra symtom. Diagnostik av CAD inkluderar undersökningarna arbetsprov (AP) och myokardscintigrafi (MPI). Båda undersökningarnas prognostiska värde påverkas dock av parametrar som elektrokardiogram (EKG), EKG-triggning, Dukes löpbands index (DTS) och Metaboliska ekvivalenter (MET). Litteraturstudiens syfte var att jämföra den prognostiska prestandan hos AP jämfört med MPI. Detta genom att studera de nämnda parametrarnas prognostiska påverkan på respektive undersökning. De använda artiklarna uppfyllde samtliga inklusionskriterier: engelska, peer-reviewed samt etiskt godkänd eller inhämtat samtycke. Databasen Pubmed, snowballsmetod samt relaterade artiklar användes vid litteraturinsamlingen. Enligt resultatet ökar ovannämnda parametrar det prognostiska värdet hos både AP och MPI. Dock visades att patienter som uppnår olika MET samt DTS-värden bättre kan riskkategoriseras med MPI. Dessutom visades MPI kunna skilja de med sämre prognos bland patienter med positiva AP-resultat, men även bland de med negativa AP-resultat. Därmed drog författarna slutsatsen att MPI har ett ökat mervärde gällande prognostik hos patienter med CAD. Fler studier som samtidigt jämför AP och MPI behövs dock för en mer fullständig slutsats. / Coronary artery disease (CAD) is the leading cause of death. This disease starts with plaque buildup in one or more coronary vessels, which can lead to chest pain among other symptoms. Diagnostics include the exercise stress test (AP) and myocardial scintigraphy (MPI). The prognostic value of both examinations depends on parameters such as electrocardiogram (ECG), ECG-gating, Duke treadmill score (DTS) and Metabolic equivalents (MET). The purpose of this study was to compare the prognostic performance of AP with MPI, by studying the prognostic effect of the mentioned parameters in each study. The used articles met all inclusion criterias: English, peer-reviewed, and ethically accepted or obtained consent. Pubmed database, snowball method and related articles were used for literature collection. According to the results, the above-mentioned parameters increase the prognostic value of AP and MPI. However, patients achieving different MET and DTS scores are better categorized with MPI. MPI was shown to differentiate those with poorer prognosis among patients with positive AP-results and those with negative AP-results. The authors concluded that MPI has an added value regarding prognosis forpatients with CAD. However, more studies comparing AP and MPI at the same time are needed to obtain a more complete conclusion.
|
3 |
Comparison between two different activity diaries for children and an activity meter.Pettersson, Ulrika January 2019 (has links)
Background: The level of activity in an individual can be the difference between health and illness. Physical inactivity can cause diseases such as osteoporosis and type-2 diabetes. It has been reported that children live an increasingly inactive life, with less than the recommended a total of 60 minutes daily for children and adolescents of 6-17 years of age. Objective: The objective was to compare two activity diaries and how the results correspond to measurements by an activity meter. Material and methods: This study included 12 children who each carried an activity meter for four days to measure Total Energy Expenditure. In parallel, they filled in two different activity diaries. In the diaries two different calculation methods were used, with a Physical Activity Ratio value or a Metabolic Equivalent of Task value which then was inserted into equations to calculate Total Energy Expenditure. Anthropometric measurements were obtained by use of a stadiometer, a caliper and a bioimpedance scale. Results: The results from the Physical Activity Ratio diary indicated a better match with the results from the activity meter. Conclusions: Between the two diaries significant difference in how the activities were estimated were found, where an overestimation could be seen in the diary that used the Metabolic Equivalent of Task. Differences could also be seen between the activity meter and both diaries, also here the difference were bigger with the Metabolic Equivalent of Task diary. The Physical Activity Ratio diary was better matched with the activity meter.
|
4 |
Physical activity in natural environments : importance of environmental quality, landscape type and promotional materialsElliott, Lewis Roland January 2016 (has links)
Physical inactivity and disconnection from natural environments threatens human health. However, research has demonstrated that natural environments potentially support health-enhancing physical activity which could confer greater physical and mental health benefits than physical activity in other types of environment. This thesis approached the study of physical activity in natural environments through three related pieces of research. Firstly, an experimental study was carried out to explore how the presence of litter in beach environments affected psychophysiological responses to exercise. Responses to exercise did not differ in littered and clean conditions but there was evidence that order effects influenced findings. Visual attention to the two scenes differed, but did not mediate differences in psychophysiological responses. Secondly, analysis of a national dataset was undertaken to explore the form and quantity of physical activity conducted within natural environments in England. A series of linear regressions revealed that higher-intensity physical activities occurred in countryside environments, but more total energy expenditure occurred in coastal environments. Thirdly, a quantitative content analysis of brochures which promote recreational walking in natural environments was conducted which investigated their use of persuasive behavioural messages. These brochures omitted behavioural techniques which may be effective at motivating inactive individuals to walk. Extending this, an online survey tested whether improving brochure content heightened intentions to walk in natural environments. By designing content based on the theory of planned behaviour, the intentions of inactive individuals to undertake walking in natural environments were increased. The findings from this thesis demonstrate that the protection of natural environments is vital for preserving and promoting active recreation and could contribute to population-level increases in physical activity with theory-based promotion in the future.
|
5 |
Gardening as a physical activity for health in older adultsPark, Sin-Ae January 1900 (has links)
Doctor of Philosophy / Department of Horticulture, Forestry, and Recreation Resources / Candice A. Shoemaker / The objectives of this study were to determine exercise intensity of common gardening tasks in older adults and to investigate if older gardeners meet the physical activity (PA) recommendations (intensity and time) through their daily gardening. Kinds of gardening tasks, body postures, and bodily pain while gardening of older gardeners were investigated and the possibility of gardening as a predictor for a physically active lifestyle and life satisfaction in older adults was determined.
Older participants were randomly recruited from the community of Manhattan, KS. To determine the exercise intensity of gardening, the heart rates of older adults were measured by radiotelemetry during gardening or garden tasks, and then oxygen uptake and energy expenditure were measured via indirect calorimetry using a submaximal graded exercise test. Overall health conditions by the Short Form 36 Health Survey (SF-36), hand functions by hydraulic hand dynamometer and pinch gauge, and bone mineral density (BMD) by dual-energy x-ray absorptiometry were measured. An observational study and weekly logs were conducted to study kinds of gardening, postures, and bodily pain of older gardeners. The Community Healthy Activities Model Program for Senior (CHAMPS) questionnaire was used to measure leisure-time PAs (frequency per week of all PAs and calories expended per week in all PAs).
In conclusion, the nine gardening tasks were found to be low to moderate intensity PA in healthy older adults (1.6 ± 3.6 METs). Gardening observed was moderate intensity (3.8 ± 1.4 METs) PA in older adults and the subjects met the PA recommendation, which is at least 30 minutes of moderate intensity PA on most days of the week through their daily gardening (moderate intensity; average 33 hrs/wk in May and 15 hrs/wk in June and July). The older gardeners showed higher values for hand function and some SF-36 domains (physical function, bodily pain, and physical summary) than older non-gardeners. Gripping, stooping, lifting, stretching, walking, standing, kneeling, sitting, and squatting were observed while older adults gardened and lower back pain was the main bodily pain reported. Furthermore, gardening was found to be a predictor for leading a physically active lifestyle and high life satisfaction in older adults.
|
6 |
Energy expenditure and physical activity patterns in children : applicability of simultaneous methodsAmorim, Paulo Roberto dos Santos January 2007 (has links)
Consistently, reports in the literature have identified that a sedentary lifestyle contributes to the progression of a range of chronic degenerative diseases. The measurement of energy expenditure and physical activity pattern in children is a challenge for all professionals interested in paediatric health and from a broader perspective, the public health fraternity charged with considering longer term health consequences of physical inactivity. The primary objective of this thesis was to identify a suitable indirect and objective measurement technique for the assessment of energy expenditure and physical activity pattern in children. The ideal characteristics of such a technique are that it should be reproducible and have been validated against a criterion reference method. To achieve this goal, a series of methodological studies were undertaken (Chapters II and III). This work was essential to increase accuracy during the individualised laboratory calibration process and further minimise prediction errors when analysing data from 7 days of monitoring under free-living conditions in the second part of the study (Chapters IV and V). In the first study to verify the combined effect of body position, apparatus and distraction on children's resting metabolic rate (RMR), experiments were carried out on 14 children aged 8-12 (mean age = 10.1 years ± 1.4). Each participant underwent 2 test sessions, one week apart under three different situations: a) using mouthpiece and nose-clip (MN) or facemask (FM); b) sitting (SEAT) or lying (LY) and c) TV viewing (TV) or no TV viewing. In the first session, following 20 min rest and watching TV, the following protocol was used: LY: 20 min - stabilisation; 10 min using MN and 10 min using FM. Body position was then changed to seated: 20 min stabilisation; 10 min using FM; 10 min using MN. In the second session, FM and MN order was changed and participants did not watch TV. Data were analysed according to the eight combinations among the three studied parameters. Repeated measures ANOVA indicated statistically significant differences for &VO2 (p=0.01) and RMR (p=0.02), with TVMNSEAT showing higher values than TVFMLY. Bland-Altman analysis showed a bias for &VO2, &VCO2, RQ and RMR between TVFMLY and TVMNSEAT of -17.8±14.5 ml.min-1, -8.8±14.5 ml. min-1, 0.03±0.05 and -115.2±101.9 kcal.d-1, respectively. There were no differences in RMR measurements due to body position and apparatus when each variable was isolated. Analyses of distraction in three of four combinations indicated no difference between TV and no TV. In summary, different parameter combinations can result in increased bias and variability and thereby reported differences among children's RMR measurement. The second study dealt with treadmill adaptation and determination of self-selected (SS) walking speed. Assessment of individual and group differences in metabolic energy expenditure using oxygen uptake requires that individuals are comfortable with, and can accommodate to, the equipment being utilised. In this study, a detailed proposal for an adaptation protocol based on the SS was developed. Experiments were carried out on 27 children aged 8-12 (mean age = 10.3±1.2 yr). Results from three treadmill tests following the adaptation protocol showed similar results for step length with no significant differences among tests and lower and no statistically significant variability within- and between-days. Additionally, no statistically significant differences between SS determined over-ground and on a treadmill were verified. These results suggest that SS speed determined over-ground is reproducible on a treadmill and the 10 min familiarisation protocol based on this speed provided sufficient exposure to achieve accommodation to the treadmill. The purpose of the third study was to verify within- and between-day repeatability and variability in children's oxygen uptake ( &VO2), gross economy (GE) [ &VO2 divided by speed] and heart rate (HR) during treadmill walking based on SS. 14 children (mean age = 10.2±1.4 yr) undertook 3 testing sessions over 2 days in which four walking speeds, including SS, were tested. Within- and between-day repeatability was assessed using the Bland and Altman method and coefficients of variability (CV) were determined for each child across exercise bouts and averaged to obtain a mean group CV value for &VO2, GE and HR per speed. Repeated measures ANOVA showed no statistically significant differences in within- or between-day CV for &VO2, GE or HR at any speed. Repeatability within and between-day for &VO2, GE and HR for all speeds was verified. These results suggest that submaximal &V O2 during treadmill walking is stable and reproducible at a range of speeds based on children's SS. In the fourth study, the objective was to establish the effect of walking speed on substrate oxidation during a treadmill protocol based on SS. Experiments were carried out on 12 girls aged 8-12 (mean age = 9.9±1.4 yr). Each participant underwent 2 test sessions, one week apart. Workloads on the treadmill included 2 speeds slower than SS (1.6 [V1] and 0.8 km.h-1 [V2] slower than SS), SS (V3), and a speed 0.8 km.h-1 faster than SS (V4). Indirect calorimetry from respired gas measurements enabled total fat (FO) and carbohydrate (CHO) oxidation rates to be calculated according to the non-protein respiratory quotient (Peronnet and Massicote, 1991) and percentage of CHO and FO calculations using equations from McGilvery and Goldstein (1983). Repeated measures ANOVA followed by a Tukey Post Hoc test (p< 0.05) was used to verify differences in CHO and FO rates among speeds. Paired T-test was used to verify differences in CHO and FO rates between tests per velocity. The reliability between-day was assessed using intraclass correlation coefficient (ICC). Results showed significant differences for CHO among all speeds, as well as significant differences for FO between V1 and V2 against V3 and V4 in both tests. Analyses between trials per velocity showed no significant substrate use differences as well as acceptable reliability. At the self-selected speed (V3) there was an accentuation in FO reduction as well as an increase in CHO oxidation. The purpose of the fifth study was to determine whether there were differences in substrate oxidation between girls (G) and women (W) during a treadmill protocol based on SS. Experiments were carried out on 12 G aged 8-12 (mean age = 9.9±1.4 yr) and 12 W aged 25-38 (mean age = 32.3±3.8 yr). The treadmill protocol included 6 min workloads followed by 5 min rest periods. Workloads included 2 speeds slower than SS (1.6 (V1) and 0.8 km.h-1 (V2) slower than SS), SS (V3), and a speed 0.8 km.h-1 faster than SS (V4). Total fat and carbohydrate (CHO) oxidation rates were calculated from indirect calorimetry according to the non-protein respiratory quotient. Repeated measures ANOVA followed by a Tukey Post Hoc test was used to verify intra-test differences in CHO and fat oxidation rates among speeds. Intergroup differences were analysed using paired T-test. Fat utilisation in W achieved a plateau at a relative velocity 0.8 km.h-1 slower than SS, but for G, fat utilisation increased until SS, and then stabilised upon reaching the higher velocity. CHO oxidation curves rose abruptly above V2 for W, while for G the acute increase occurred after SS (V3). Collectively, these results indicate that as walking intensity increases G are able to meet the energy demands of the work by increasing fat oxidation together with the increased CHO oxidation up to SS. In contrast for W, increasing CHO oxidation is associated with an early decrease in fat utilisation at a velocity slower than the self-selected speed. The sixth study dealt with validation of indirect techniques for the measurement of energy expenditure in free-living conditions against the DLW technique. Experiments were carried out on 19 children aged 8-12 (mean age = 10.3±1.0 yr). To indirectly predict energy expenditure 12 different procedures were used. Only one procedure, combining activity and heart rate (AHbranched), was based on a group equation, the others were based on individualised regression. Three of the individually-based techniques were able to accurately predict energy expenditure in free-living conditions. These tecniques were HRPAnetRMR using HRnet [HR exercise minus sleep HR (SHR)] against PAnet (measured PA exercise minus measured RMR) and upper and lower body equations corrected by RMR; HRPAnet4act using the same procedure but corrected by the mean resting &VO2 for 4 resting activities [(4act) = supine watching TV, sitting watching TV, sitting playing computer games and standing], and HRPALBnet4act using only lower body activities and corrected by 4act. HRPAnetRMR was only slightly more accurate than HRPAnet4act and HRPALBnet4act, but this technique is only adjusted by RMR whereas the other two are heavily dependent on more complex laboratory calibration. Bland and Altman (1986) analyses showed no significant differences between AHbranched predicted and measured TEE using the DLW technique. A SEE of 79 kcal.d-1 and a mean difference of 72 kcal.d-1, with a 95% CI ranging from -238 to 93.9 kcal.d-1 was found. In addition, no significant differences between predicted HRPAnetRMR and measured TEE using DLW were found, showing an SEE of 99 kcal.d-1 and a mean difference of -67 kcal.d-1, and a 95% CI ranging from -276.6 to 141.9 kcal.d-1. AHbranched and HRPAnetRMR were both valid and similarly suitable for the prediction of energy expenditure in children under free-living conditions. Significant associations between DLWAEE and the after-school time window indicated that this time window as an important discretionary period representative of children physical activity. However, the duration of the after-school time windows should be more carefully considered. Accelerometer data showed a better association between the largest after-school time window (3.5 hr) and measured TEE. The final study, completed with 19 children aged 8-12 (10.3±1.0 yr) highlighted, under laboratory conditions across a range of walking and running speeds, the inadequacy of the use of the standard MET in children. This traditional approach overestimates energy expenditure with an increased difference linearly related to speed increments. Minute-by-minute analyses of 7 days of free-living monitoring showed an average overestimation of 64 minutes per day for moderate-to-vigorousphysical- activity (MVPA) using the standard MET compared with the individually measured MET. For all intensities, these differences were statistically significant (p< 0.001). The second part of this study showed a variability of 20% in the average time spent at MVPA when comparing HR I 140 bpm and HR > 50%P &VO2 (P &VO2 = the highest &VO2 observed during an exercise test to exhaustion). Results of the current study compared to observations in the literature showed that HR I 140 bpm consistently estimates lower MVPA time than HR > 50%P &VO2. When these two PA indices were compared with individual and standard MET measured minute-byminute, statistically significant differences were verified among all of them at MPA, but no differences were verified at VPA, except between individual and standard METs. However, whether each one of the PA indices used are under- or overestimating time at MVPA is still debatable due to the lack of a gold standard. Finally, each index used in this study classified different numbers of participants as achieving the PA target of 60 min.d-1. The wide variability between indices when attempting to classify children who are achieving the recommended target is cause for great concern because habitually these indices are utilised as screening tools in paediatric and public health settings and used to guide behavioural interventions.
|
Page generated in 1.7501 seconds