RESUMEN
OBJECTIVE: The purpose of these experiments was to develop a rating-of-fatigue (ROF) scale capable of tracking the intensity of perceived fatigue in a variety of contexts. METHODS: Four experiments were carried out. The first provided the evidential basis for the construction of the ROF scale. The second tested the face validity of the ROF, and the third tested the convergent and divergent validity of the ROF scale during ramped cycling to exhaustion and 30 min of resting recovery. The final experiment tested the convergent validity of the ROF scale with time of day and physical activity (accelerometer counts) across a whole week. RESULTS: Modal selections of descriptions and diagrams at different levels of exertion and recovery were found during Experiment 1 upon which the ROF scale was constructed and finalised. In Experiment 2, a high level of face validity was indicated, in that ROF was reported to represent fatigue rather than exertion. Descriptor and diagrammatic elements of ROF reportedly added to the coherence and ease of use of the scale. In Experiment 3, high convergence between ROF and various physiological measures were found during exercise and recovery (heart rate, blood lactate concentration, oxygen uptake, carbon dioxide production, respiratory exchange ratio and ventilation rate were all P < 0.001). During ramped cycling to exhaustion ROF and RPE did correspond (P < 0.0001) but not during recovery, demonstrating discriminant validity. Experiment 4 found ROF to correspond with waking time during each day (Mon-Sun all P < 0.0001) and with physical activity (accelerometer count) (Mon-Sun all P < 0.001). CONCLUSIONS: The ROF scale has good face validity and high levels of convergent validity during ramped cycling to exhaustion, resting recovery and daily living activities. The ROF scale has both theoretical and applied potential in understanding changes in fatigue in a variety of contexts.
Asunto(s)
Ejercicio Físico , Fatiga , Esfuerzo Físico/fisiología , Adulto , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Consumo de Oxígeno/fisiología , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
BACKGROUND: The Cardiac Depression Scale (CDS) has been designed to measure depressive symptoms in patients with heart disease. There is no Arabic version of the CDS. We translated and validated the CDS in an Arabic sample of patients with heart disease. METHODS: Forward and back translation of the CDS was followed by assessment of cultural relevance and content validity. The Arabic version of the CDS (A-CDS) and the Arabic version of the Hospital Anxiety and Depression Scale (A-HADS) were then administered to 260 Arab in-patients with heart disease from 18 Arabic countries. Construct validity was assessed using exploratory factor analysis with polychoric correlations. Internal consistency was assessed using ordinal reliability alpha and item-to-factor polychoric correlations. Concurrent validity was assessed using Pearson's correlation coefficient between the A-CDS and the depression subscale of the A-HADS (A-HADS-D). RESULTS: Cultural relevance and content validity of the A-CDS were satisfactory. Exploratory factor analysis revealed three robust factors, without cross-loadings, that formed a single dimension. Internal consistency was high (ordinal reliability alpha for the total scale and the three factors were .94, .91, .86, and .87, respectively; item-to-factor correlations ranged from .77 to .91). Concurrent validity was high (r=.72). The A-CDS demonstrated a closer to normal distribution of scores than the A-HADS-D. LIMITATIONS: Sensitivity and specificity of the A-CDS were not objectively assessed. CONCLUSIONS: The A-CDS appears to be a valid and reliable instrument to measure depressive symptoms in a representative sample of Arab in-patients with heart disease.
Asunto(s)
Depresión/diagnóstico , Cardiopatías/psicología , Escalas de Valoración Psiquiátrica/normas , Psicometría/instrumentación , Adulto , Anciano , Anciano de 80 o más Años , Árabes , Depresión/etnología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Traducciones , Adulto JovenRESUMEN
OBJECTIVE: to investigate the effect of all-out cycling test duration on indices of power, anaerobic lactic energy metabolism, perceived exertion and mood. METHODS: nine physically active men undertook four all-out cycling tests of 5, 15, 30 or 45 s from seated stationary start on an ergometer fit with power cranks. The participants completed a Profile of Mood States questionnaire before each test and indicated perceived exertion immediately post-test (Borg 6-20 scale). Indices of anaerobic lactic metabolism were determined from blood lactate concentrations. RESULTS: pacing strategy was apparent in the 45-s tests with lower peak (p<0.01) and mean power in the initial 10 s compared to the 5- and 15-s tests (p<0.05). The first 15 s of the 30- and 45-s tests revealed lower fatigue indices compared to the 15-s tests (p<0.05) indicating some pacing in the 30-s tests. Perceived exertion increased with duration, with no difference between the 15- and 30-s tests (p>0.05). Extravascal lactate generation (reflecting exercising muscle lactate production) explained 59% of the variance in perceived exertion. There was no effect of knowledge of test duration on mood states or total mood disturbance (p>0.05). CONCLUSIONS: an all-out pacing strategy was apparent for at least up to 15 s, with indicators of dampened power in both 30 and 45 s sprints. Reduced power at the start of all-out long-duration sprints support a central control of at least initial pacing strategy.
Asunto(s)
Afecto/fisiología , Anticipación Psicológica/fisiología , Ciclismo/fisiología , Metabolismo Energético/fisiología , Ejercicio Físico/fisiología , Ácido Láctico/metabolismo , Ergometría , Fatiga/etiología , Humanos , Masculino , Consumo de Oxígeno/fisiología , Percepción/fisiología , Intercambio Gaseoso Pulmonar/fisiología , Factores de Tiempo , Adulto JovenRESUMEN
OBJECTIVE: To investigate how experience and feedback influence pacing and performance during time trial cycling. DESIGN: Twenty-nine cyclists performed three 20 km cycling time trials using a Computrainer. The first two time trials (TT1 and TT2) were performed (1) without any performance feedback (n = 10), (2) with accurate performance feedback (n = 10) or (3) with false feedback showing the speed to be 5% greater than the actual speed (n = 9). All participants received full feedback during the third time trial (TT3), and their performance and pacing data were compared against TT2. RESULTS: Completion time, average power and average speed did not change among the false feedback group, but their pacing strategy did change as indicated by a lower average cadence, 89.2 (SD 5.2) vs 96.4 (6.8) rpm, p<0.05, and higher power during the first 5 km (SMD = 39, 36, 36, 27 and 27 W for 1-5 km respectively). Pacing changed among the blind feedback group indicated by a faster completion time, 35.9 (3.1) vs 36.8 (4.4) min, p<0.05, and power increases during the final 5 km (SMD = 14, 13, 18, 23 and 53 W for 16-20 km respectively). No performance or pacing changes were observed among the accurate feedback group. CONCLUSIONS: Pacing is influenced by an interaction between feedback and previous experience. Conscious cognitive processes that lead to ratings of perceived exertion and pacing appear to be influenced by previous experience.
Asunto(s)
Ciclismo/fisiología , Retroalimentación Fisiológica/fisiología , Adulto , Análisis de Varianza , Metabolismo Energético/fisiología , Ejercicio Físico/fisiología , Humanos , Masculino , Percepción , Resistencia Física/fisiología , Práctica Psicológica , Factores de TiempoRESUMEN
The purpose of this study was to develop a practical and reliable squash specific incremental test for estimating maximal oxygen uptake (VO(2max)). VO(2max) was measured using breath-by-breath online gas analysis among 11 male and 10 female squash players during a maximal incremental running treadmill protocol. All subjects performed a specially designed maximal squash specific incremental test (SSIT) until fatigue on two separate occasions. There were positive intra-class correlations for the two SSIT trials for time to fatigue (r=0.998, p<0.001) but the second trial was shorter (t=2.7, p<0.05) due to less stable scores among female players. A positive correlation was found between SSIT performance and VO(2max) (r=0.924, p<0.001). SSIT time to fatigue and VO(2max) regression equations were used to produce a table to predict VO(2max) from SSIT performance. SSIT was found to be a reliable and valid method of estimating VO(2max) among squash players. A balance between usability and squash specificity was achieved in the design of the SSIT without jeopardising its purpose of estimating VO(2max). SSIT is inexpensive, quick to set up and simple to administer compared to other squash specific tests and can be used with novice through to elite players.
Asunto(s)
Prueba de Esfuerzo , Consumo de Oxígeno/fisiología , Deportes de Raqueta/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Reproducibilidad de los Resultados , Carrera/fisiología , Sensibilidad y Especificidad , Estadística como Asunto , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Performance and metabolic profiles of the Wingate Anaerobic Test (WAnT) were compared between a mechanically resisted (ME) and an electro-magnetically braked (EE) cycle ergometer. Fifteen healthy subjects (24.0+/-3.5 years, 180.5+/-6.1 cm, 75.4+/-11.9 kg) performed a WAnT on ME, and EE 3 days apart. Performance was measured as peak power (PP), minimum power (MP), mean power (AP), time to PP (TTPP), fatigue rate (FR), and maximum cadence (RPM(MAX)). Lactic (W (LAC)) and alactic (W (PCR)) anaerobic energy were calculated from net lactate appearance and the fast component of post-exercise oxygen uptake. Aerobic metabolism (W (AER)) was calculated from oxygen uptake during the WAnT. Total energy cost (W (TOT)) was calculated as the sum of W (LAC), W (PCR), and W (AER). There was no difference between ME and EE in PP (873+/-159 vs. 931+/-193 W) or AP (633+/-89 vs. 630+/-89 W). In the EE condition TTPP (2.3+/-0.7 vs. 4.3+/-0.7 s) was longer (P<0.001), MP (464+/-78 vs. 388+/-57 W) was lower (P<0.001), FR (15.2+/-5.2 vs. 20.5+/-6.8%) was higher (P<0.005), and RPM(MAX) (168+/-18 vs. 128+/-15 rpm) was slower (P<0.001). There was no difference in W (TOT) (1,331+/-182 vs. 1,373+/-120 J kg(-1)), W (AER) (292+/-76 vs. 309+/-72 J kg(-1)), W (PCR) (495+/-153 vs. 515+/-111 J kg(-1)) or W (LAC) (545+/-132 vs. 549+/-141 J kg(-1)) between ME and EE devices. The EE produces distinctly different performance measures but valid metabolic WAnT results that may be used to evaluate anaerobic fitness.