Decrement in Professional Cyclists' Performance After a Grand Tour.

PURPOSE: To analyze professional cyclists' performance declines after, and the exercise demands during, a Grand Tour. METHODS: Seven professional cyclists performed 2 incremental exercise tests, 1 wk before and the day after the Vuelta España. During the race the exercise demands were analyzed on the basis of heart rate (HR). Three intensity zones were established according to reference HR values corresponding to the ventilatory- (VT) and respiratory-compensation (RCT) thresholds determined during the prerace test. In addition, exercise demands for the last weeks of the Vuelta were recalculated using the reference HR determined during the postrace test for the 3rd week and averaging the change observed in the VT and RCT per stage for the 2nd week. The reference HR for the beginning of the 2nd week was estimated. RESULTS: A significant (P-value range, .044-.000) decrement in oxygen uptake, power output, and HR at maximal exercise, VT, and RCT was found after the race. Based on the prerace test, the mean time spent daily above the RCT was 13.8 ± 10.2 min. This time decreased -1.2 min·day-1 across the race. When the exercise intensity was corrected according to the postrace test, the time above RCT (34.1 ± 9.9 min) increased 1.0 min·day-1. CONCLUSION: These data indicate that completing a Grand Tour may result in a significant decrement in maximal and submaximal endurance performance capacity. This may modify reference values used to analyze exercise demands. As a consequence, the high-intensity exercise performed by cyclists may be underestimated.

Reliability and Seasonal Changes of Submaximal Variables to Evaluate Professional Cyclists.

PURPOSE: The aim of this study was to determine the reliability and validity of several submaximal variables that can be easily obtained by monitoring cyclists' performances. METHODS: Eighteen professional cyclists participated in this study. In a first part (n = 15) the test-retest reliability of heart rate (HR) and rating of perceived exertion (RPE) during a progressive maximal test was measured. Derived submaximal variables based on HR, RPE, and power output (PO) responses were analyzed. In a second part (n = 7) the pattern of the submaximal variables according to cyclists' training status was analyzed. Cyclists were assessed 3 times during the season: at the beginning of the season, before the Vuelta a España, and the day after this Grand Tour. RESULTS: Part 1: No significant differences in maximal and submaximal variables between test-retest were found. Excellent ICCs (0.81-0.98) were obtained in all variables. Part 2: The HR and RPE showed a rightward shift from early to peak season. In addition, RPE showed a left shift after the Vuelta a España. Submaximal variables based on RPE had the best relationship with both performance and changes in performance. CONCLUSION: The present study showed the reliability of different maximal and submaximal variables used to assess cyclists' performances. Submaximal variables based on RPE seem to be the best to monitor changes in training status over a season.

Physiological work demands of Spanish wildland firefighters during wildfire suppression.

PURPOSE: The aim of this study was to analyze the physiological demands and thermal strain of wildland firefighters during real wildfire suppression. METHODS: The response of core temperature and heart rate (HR) were analyzed in 200 wildland firefighters during wildfire suppression activities of different duration: <1 h (n = 52), 1-3 h (n = 70), 3-5 h (n = 44), and >5 h (n = 34). The exercise workload (TRIMP), the physiological strain index (PSI), and cumulative heat strain index (CHSI) were calculated using the time spent in different intensity zones, the HR, and core temperature. RESULTS: Mean HR was significantly higher (P < 0.05) in wildfires <1 h (133 ± 2 bpm) and 1-3 h (128 ± 1 bpm) versus 3-5 h (120 ± 3 bpm) and >5 h (116 ± 32 bpm). The time spent in higher intensity zones increased (P < 0.05) when wildfire duration increased. TRIMP accumulation increased with wildfire duration (54.9 ± 3.2, 167.4 ± 5.9, 296.0 ± 8.3, 511.7 ± 12.8 in <1, 1-3, 3-5, and >5 h, respectively). Neither core temperature (37.4 ± 0.1°C) nor PSI (4.5 ± 0.2) were influenced by wildfire duration. The CHSI increased (p < 0.05) in the following order: <1 h (104 ± 23), 1-3 h (1,396 ± 275), 3-5 h (4,586 ± 387), and >5 h (10,703 ± 710). CONCLUSIONS: The results demonstrate the high work strain sustained by Spanish wildland firefighters during wildfire suppression. Both workload and CHSI increased with the wildfires duration although the pace of work was faster in wildfires of a shorter duration.

Exercise intensity and load during different races in youth and junior cyclists.

This study analyzed and compared the exercise intensity exerted by Youth and Junior cyclists in single-day and stage races. Heart rate was measured during the races and categorized according to 3 intensity zones: Z1 (below the ventilatory threshold [VT]), Z2 (between the VT and the respiratory compensation threshold [RCT]), and Z3 (above the RCT). The training impulse (TRIMP) was calculated by multiplying the sum of the time spent in each zone by 1, 2, and 3, respectively. Time spent in Z1, Z2, and daily TRIMP were significantly higher (p < 0.05) in Junior than in Youth in both single-day races (21.6 ± 1.9 min vs. 14.8 ± 1.6 min, 55.4 ± 2.3 min vs. 34.7 ± 1.9 min, and 257 ± 6 vs. 194 ± 6, respectively) and stage races (49.2 ± 3.4 min vs. 23.5 ± 4.7 min, 51.2 ± 2.6 min vs. 35.3 ± 3.7 min, and 201 ± 10 vs. 147 ± 7, respectively). In Youth and Junior, time and percentage time spent in Z3 and daily TRIMP were also significantly higher (p < 0.05) in single-day races (39.0 ± 1.9 min, 40.2 ± 1.9% and 225 ± 7) than in stage races (13.9 ± 1.8 min, 15.2 ± 1.8% and 174 ± 8). In conclusion, the present study showed that races in both Youth and Junior categories are highly demanding and that their intensity and exercise load are related to the total race duration.

Intensidad de esfuerzo realizado en la extinción de incendios forestales / Exercice intensity during wildfire suppression

El Personal Especialista en Extinción de Incendios Forestales (PEEIF) desarrolla su trabajo en condiciones que exigen un gran esfuerzo físico. La actividad realizada está condicionada por diversos factores, entre ellos las altas temperaturas, la dureza orográfica, la inhalación de humos y la deshidratación. En el presente estudio se ha cuantificado el esfuerzo realizado por el PEEIF (n = 200) en la extinción de diferentes incendios forestales (n = 79). Así, en función del consumo de oxígeno máximo (VO2max) de los sujetos se establecieron tres zonas de intensidad de esfuerzo: moderada (por debajo del 50% VO2max), alta (entre el 50 y el 75% VO2max) y muy alta (por encima del 75% VO2max). El tiempo de permanencia en cada una de estas zonas se utilizó para calcular la carga de trabajo, multiplicando por las constantes 1, 2 o 3, respectivamente. La duración media de los incendios fue de 225,3 ± 6,2 min. La frecuencia cardíaca (FC) media obtenida por los sujetos fue de 117 ± 2 ppm. Los sujetos permanecieron 185,5 ±5,4, 33,1 ± 1,5 y 4,5 ± 0,5 min en la zona de moderada, alta y muy alta intensidad, respectivamente. Cuando se compararon los incendios en función de su duración no se obtuvieron diferencias significativas en el porcentaje del tiempo total de trabajo en la zona de alta intensidad. Sin embargo, a medida que la duración de los incendios fue mayor el porcentaje de trabajo en la zona de moderada intensidad aumentó en detrimento del porcentaje de trabajo a alta intensidad. Se obtuvo una carga de trabajo media de aproximadamente 265 unidades. En conclusión, el esfuerzo desarrollado por el PEEIF en la extinción de incendios fue muy exigente, fundamentalmente debido a la duración delos incendios. El conocimiento de estas demandas puede ayudar al desarrollo de programas de entrenamiento más específicos que permitan afrontar la extinción de los incendios de manera más eficiente y segura (AU)

The wildland firefighters (PEEIF) develop their work inconditions that require great physical effort (eg., high temperature, hardness orographic, smoke exposure, dehydration). The aim of this study was to quantify the exercise effort exerted by the PEEIF (n = 200) in different wildfires extinction (n = 79). According to the maximum oxygen consumption values (VO2max), three intensity zones were established: moderate (below 50% VO2max), high (between50-75% VO2max) and very high (above 75% VO2max). The workload was computed by multiplying the duration of wildfire within each zone by a multiplier for that intensity zone (zone 1 = 1, zone 2 = 2, zone 3 = 3) and reported as TRIMP. The mean duration of the wildfires was 225.3 ±6.2 min and the mean heart rate (HR) 117 ± 2 bpm, representing 60.6 ± 1.1 % of the maximum HR. Subjects spent 185.5 ± 5.4, 33.1 ± 1.5 and 4.5 ± 0.5 min in moderate, high and very high exercise intensity zones, respectively. When we compared wildfires according to its duration, no significant differences in the percentage of total time spentin high intensity zone were found. However, when wildfires duration was higher, the percentage of total time spentin moderate intensity zone increased and the percentage of total time spent in high-intensity zone decreased. The mean workload (TRIMP) was ~265 units. In conclusion, the present study shows that wildfire extinction is highly demanding. It is likely that the workload is modulated by total wildfire duration. Finally, the knowledge of these demands can help to develop more specific and scientific training programs (AU)