Expanding Knowledge About the Effect of Measurement Time on Session Rating of Perceived Exertion.

ABSTRACT: Rodríguez-Marroyo, JA, Blanco, P, Foster, C, Villa, JG, and Carballo-Leyenda, B. Expanding knowledge about the effect of measurement time on session rating of perceived exertion. J Strength Cond Res 37(1): 230-233, 2023-The purpose of this study was to analyze the effect of postexercise rating times (from 0 minutes to 4 weeks) on session rating of perceived exertion (sRPE). Twenty-five athletes (12 women and 13 men) from different sports (sprinting, endurance running, cycling, and volleyball) were involved in this study. At least 3 training sessions per subject were quantified based on sRPE using a visual analog scale. The scale was administered immediately after, at 5, 10, 20, and 30 minutes, 24, 48, and 72 hours, and 1, 2, 3, and 4 weeks postexercise. In addition, the effect of rating time on sRPE was studied according to the training intensity. For this, the training sessions were classified (based on the 30-minute rating) as easy (sRPE < 3), moderate (sRPE 3-5), and hard (sRPE > 5). A significant (p < 0.001) main effect of the postexercise rating time on sRPE was found. There were significant (p < 0.05) differences between sRPE obtained at 30 minutes and those obtained immediately after hard training sessions and at 1, 2, 3, and 4 weeks postexercise. There was no significant effect of rating time on sRPE in the easy and moderate training sessions. In conclusion, the present data suggest that athletes' sRPE may be obtained in a valid and reliable manner within a time frame of 5 minutes to 72 hours posttraining. The effect of postexercise rating time on sRPE seems to be conditioned by the training intensity, especially in those training sessions whose training intensity was high (sRPE > 5).

Effect of the Cooldown Type on Session Rating of Perceived Exertion.

PURPOSE: This study investigated the effect of cooldown modality (active vs passive) and duration (5, 10, and 15 min) on session rating of perceived exertion (sRPE). Secondarily, the possible influence of training sessions' demand on this effect was studied. METHODS: A total of 16 youth male soccer players (15.7 [0.4] y) completed 2 standardized training sessions per week across 6 weeks. During weeks 1 to 2, 3 to 4, and 5 to 6, cooldown lengths of 15, 10, and 5 minutes were studied, respectively. Using a crossover design, players were randomly assigned to 2 groups and each group performed 1 of 2 different cooldown interventions. Passive and active cooldown interventions based on static stretching and running exercises were studied. Heart rate and sRPE were recorded during all training sessions. RESULTS: The lowest sRPE was observed when passive cooldown was performed. When the hardest training sessions were considered, a significant main effect of cooldown modality (P < .01) and duration (P < .05) and an interaction effect between these variables (P < .05) on sRPE were obtained. The lowest (P < .01) sRPE was observed during the longest cooldown (15 min). CONCLUSION: The findings suggest that sRPE may be sensitive to the selected cooldown modality and duration, especially following the most demanding training sessions.

Effectiveness of a Generic vs. Specific Program Training to Prevent the Short-Term Detraining on Repeated-Sprint Ability of Youth Soccer Players.

Rodríguez-Fernández, A, Villa, JG, Sánchez-Sánchez, J, and Rodríguez-Marroyo, JA. Effectiveness of a generic vs. specific program training to prevent the short-term detraining on repeated-sprint ability of youth soccer players. J Strength Cond Res 34(8): 2128-2135, 2020-The aim of this study was to analyze the effects of 2 short-term training programs to prevent the negative effect of detraining on repeated-sprint ability (RSA) performance. The study was performed during a 2-week midseason break without official matches. Forty-five youth soccer players (17.7 ± 0.8 years, 175.4 ± 5.5 cm, and 67.2 ± 5.1 kg) were split into 3 groups during the intervention period: inactivity group (IN; N = 16), generic high-intensity training group (GG; N = 15), and specific training group (SG; N = 14). IN was instructed to avoid performing physical activity during the 2-week training intervention. However, GG and SG performed 8 training sessions. GG performed a generic aerobic interval training consisting of 4 repetitions of 4 minutes of exercise at 90-95% of maximal heart rate. SG performed a specific conditioning through small-sided games (4 vs. 4, 4 × 4-minute) and repeated sprints (6 × 30-m). Testing sessions included an RSA test and a Yo-Yo intermittent recovery test level 1 (YYIR1). Repeated-sprint ability performance only improved after the training intervention in SG (∼2%, p < 0.01, (Equation is included in full-text article.)= 0.23-0.25). Both GG and IN declined their performance in post-test (∼2%, p < 0.01, (Equation is included in full-text article.)= 0.19-0.22). No significant effect, group × time, was analyzed for YYIR1 performance. This study suggests that only specific training, based on small-sided games and repeated sprints, leads to short-term improvements on RSA performance in youth soccer players.

Characterizing Wildland Firefighters' Thermal Environment During Live-Fire Suppression.

Wildland firefighters work under adverse environments (e.g., heat and fire exposure), which contribute to increasing the heat strain. Despite this there is a paucity of knowledge about the thermal environment in real wildfire suppression scenarios. Therefore, the main purpose of this study was to characterize the environmental thermal exposure and the risk of heat burn injuries during real wildfire suppression (n = 23). To characterize the wildland firefighter's (n = 5) local thermal exposure, measurements of air temperature and heat flux were performed. Heat flux measurements were made using four thin-planar heat flux sensors. Two were affixed on the outer surface of the garment on the left chest and thigh. Two other sensors were placed on the inner surface of the fabric in parallel to those placed externally. Four thermal classes were defined based on the heat flux across the inner sensors (≤1000, ≤5000, ≤7000, and >7000 W⋅m-2). The risk of pain and first-degree burns were calculated using the dose of thermal radiation method. The inner sensors mean and maximum heat flux and environment temperature were 286.7 ± 255.0 and 2370.4 ± 3004.5 W⋅m-2 and 32.6 ± 8.9 and 78.0 ± 8.9°C, respectively. Approximately 81, 15, and 3.5% of the exposure time the heat flux was ≤1000, >1000-5000, and >5000 W⋅m-2, respectively. The highest average and maximum thermal dose values were ∼94 and ∼110 (kW⋅m-2)4/3⋅s. In conclusion, the thermal exposure obtained may be considered light. However, high thermal exposure values may be obtained in punctual moments, which can elicit first-degree burns.

Fractional Contribution of Wildland Firefighters' Personal Protective Equipment on Physiological Strain.

Activities performed by wildland firefighters are carried out wearing a personal protective equipment (PPE). Although the PPE protects workers from a wide variety of hazards, it may increase their physiological response and limit their performance. The aim of this study was to analyze the effect of the protective clothing (PPC) and the rest of the PPE elements (i.e., helmet, neck shroud, gloves, goggles, and mid-calf leather boots) on the wildland firefighters' thermophysiological response during a moderate-intense exercise. Six male wildland firefighters performed, in a counterbalanced order, a 120 min graded exercise test wearing three different clothing configurations: (i) a traditional short sports gear (SG), (ii) a PPC, and (iii) a complete firefighters' PPE. Trials were conducted on separate days at the same time of the day (12:00-15:00 h) and under climate-controlled conditions (∼30°C and ∼30% relative humidity). Heart rate, respiratory gas exchange, gastrointestinal and skin temperature, blood lactate concentration were recorded throughout the tests. Additionally, parameters of heat balance were estimated. Exercise time was shorter (p < 0.001) wearing the PPE (62.4 ± 13.3 min) than with the PPC (115.5 ± 5.0 min) and SG (118.2 ± 20.7 min). The increment of gastrointestinal temperature with the PPE (1.8 ± 0.3°C) was greater (p < 0.05) than the observed in PPC (1.2 ± 0.6°C) and SG (1.0 ± 0.2°C). The use of PPC increased (p < 0.05) subjects' metabolic demand and skin temperature versus SG during the last 20 min of the test. The sweat retention in the PPE (1,045.7 ± 214.7 g) and PPC (978.3 ± 330.6 g) was significantly higher than that obtained in the SG (510.0 ± 210.0 g). Sweat efficiency decreased (p < 0.05) in the following order: PPE (45.6 ± 18.3%), PPC (64.3 ± 7.8%), and SG (79.3 ± 7.0%). These results highlight the importance of the PPE elements in the subjects' thermal strain. The reduction in the sweat evaporation produced by the PPE, together with the ensemble mass caused a substantial increase in the subjects' thermophysiological response. As a consequence the performance was reduced by ∼50%.

Impact of Different Personal Protective Clothing on Wildland Firefighters' Physiological Strain.

Wildfire firefighting is an extremely demanding occupation performed under hot environment. The use of personal protective clothing (PPC) is needed to protect subjects from the thermal exposure. However, the additional use of PPC may increase the wildland firefighters' physiological strain, and consequently limit their performance. The aim of this study was to analyze the effect of four different PPC on the physiological strain of wildland firefighters under moderate conditions (30°C and 30% RH). Eight active and healthy wildland firefighters performed a submaximal walking test wearing a traditional short sports gear and 4 different PPC. The materials combination (viscose, Nomex, Kevlar, P-140 and fire resistant cotton) used during the PPC manufacturing process was different. During all tests, to simulate a real scenario subjects wore a backpack pump (20 kg). Heart rate, respiratory gas exchange, gastrointestinal temperature, blood lactate concentration, perceived exertion and temperature and humidity underneath the PPC were recorded throughout tests. Additionally, parameters of heat balance were estimated. Wearing a PPC did not cause a significant increase in the subjects' physiological response. The gastrointestinal temperature increment, the relative humidity of the microclimate underneath the PPC, the sweat residue in PPC, the sweat efficiency, the dry heat exchange and the total clothing insulation were significantly affected according to the PPC fabric composition. These results suggest that the PPC composition affect the moisture management. This might be taken into account to increase the wildland firefighters' protection in real situations, when they have to work close to the flames.

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.

Validity, Reliability, and Sensitivity of a Volleyball Intermittent Endurance Test.

PURPOSE: To analyze the concurrent and construct validity of a volleyball intermittent endurance test (VIET). The VIET's test-retest reliability and sensitivity to assess seasonal changes was also studied. METHODS: During the preseason, 71 volleyball players of different competitive levels took part in this study. All performed the VIET and a graded treadmill test with gas-exchange measurement (GXT). Thirty-one of the players performed an additional VIET to analyze the test-retest reliability. To test the VIET's sensitivity, 28 players repeated the VIET and GXT at the end of their season. RESULTS: Significant (P < .001) relationships between VIET distance and maximal oxygen uptake (r = .74) and GXT maximal speed (r = .78) were observed. There were no significant differences between the VIET performance test and retest (1542.1 ± 338.1 vs 1567.1 ± 358.2 m). Significant (P < .001) relationships and intraclass correlation coefficient (ICC) were found (r = .95, ICC = .96) for VIET performance. VIET performance increased significantly (P < .001) with player performance level and was sensitive to fitness changes across the season (1458.8 ± 343.5 vs 1581.1 ± 334.0 m, P < .01). CONCLUSIONS: The VIET may be considered a valid, reliable, and sensitive test to assess the aerobic endurance in volleyball players.

Effects of 5-week pre-season small-sided-game-based training on repeat sprint ability.

BACKGROUND: Numerous studies have analyzed during competitive season different conditioning programs to improve soccer players' repeat sprint ability (RSA). However, few studies have focused on analyzing what happens with this ability after small-sided-game- (SSG-) -based training. Thus, the aim of this study was to determine the changes in physical performance after 5 weeks of pre-season training composed of SSGs in amateur soccer players. METHODS: Twenty-four male soccer players performed RSA, a sit-and-reach and two vertical jump (squat and countermovement jump) tests before and after 5 weeks of pre-season training mainly consisting of SSGs. RESULTS: The pre-season training induced a significant improvement (P<0.05) in RSA and flexibility performance. However, no significant improvements were analyzed during the vertical jump tests. Soccer players with worst initial RSA performance, improved significantly (P<0.05) their fastest sprint (~2.5%) and the total time (~3.0%) during the RSA. No changes in soccer players with better initial RSA performance were analyzed. CONCLUSIONS: A pre-season composed of training sessions performed basically through SSGs during 5 week improves the RSA performance in amateur soccer players, especially in those with the worst initial performance level.

Validity and Test-Retest Reliability of the TIVRE-Basket Test for the Determination of Aerobic Power in Elite Male Basketball Players.

The aims of this study were to (a) determine the relationship between performance on the court-based TIVRE-Basket test and peak aerobic power determined from a criterion laboratory-based incremental treadmill test and (b) to examine the test-retest reliability of the TIVRE-Basket test in elite male basketball players. To address aim 1, 36 elite male basketball players (age: 25.2 ± 4.7 years, weight: 94.1 ± 11.4 kg, height: 195.83 ± 9.6 cm) completed a graded treadmill exercise test and the TIVRE-Basket within 72 hours. The mean distance recorded during the TIVRE-Basket test was 4001.8 ± 176.4 m, and mean VO2 peak was 54.7 ± 2.8 ml · kg(-1) · min(-1), and the correlation between the 2 parameters was r = 0.824 (p ≤ 0.001). Linear regression analysis identified TIVRE-Basket distance (in meters) as the only unique predictor of VO2 peak in a single variable plus constant model: VO2 peak = 2.595 + (0.13 × TIVRE-Basket distance [in meters]). Performance on the TIVRE-Basket test accounted for 67.8% of the variance in VO2 peak (t = 8.466, p ≤ 0.001, 95% confidence interval: 0.01-0.016, SEE: 1.61). To address aim 2, 20 male basketball players (age: 26.7 ± 4.2 years, height: 1.94 ± 0.92 cm, weight: 94.0 ± 9.1 kg) performed the TIVRE-Basket test on 2 occasions. There was no significant difference in total distance covered between trial 1 (4138.8 ± 677.3 m) and trial 2 (4188.0 ± 648.8 m; t = 0.5798, p = 0.5688). Mean difference between trials was 49.2 ± 399.5 m, with an intraclass correlation coefficient of 0.85 suggesting a moderate level of reliability. Standardized typical error of measurement was 0.88%, representing a moderate degree of trial-to-trial error, and the Coefficient of Variation (CV) was 6.3%. The TIVRE-Basket test therefore represents a valid and moderately reliable court-based sport-specific test of aerobic power for use with individuals and teams of elite-level male basketball players. Future research is required to ascertain its validity and reliability in other basketball populations, for example, across age groups, at different levels of competition, in females and in different forms of the game, for example, wheelchair basketball.

Effects of seven weeks of static hamstring stretching on flexibility and sprint performance in young soccer players according to their playing position.

BACKGROUND: The aim of this study was to investigate the effect of 7 weeks of static hamstring stretching on flexibility and sprint performance in young soccer players. METHODS: One hundred and three healthy soccer players voluntarily participated in this study. Subjects were assigned to a control group (N.=22, 16.5±0.7 years, 174.0±5.4 cm and 68.0±6.8 kg) and an experimental group (N.=81, 18.9±1.8 years, 176.0±5.8 cm and 68.2±8.4 kg). All subjects performed a sit-and-reach and a 30-m Sprint Test to assess their flexibility performance and sprinting ability, respectively, before and after 7 weeks of static hamstring stretching program. The static stretching program consisted of 4 stretching exercises performed at the end of the training session during 6 days per week. Each stretch was held for 30-s and performed twice with a 15-s rest between. RESULTS: Flexibility was significantly (P<0.05) improved for the experimental group. This improvement was analyzed in all playing positions studied. There were significant differences (P<0.05) between pre and post 30-m Sprint Test in both groups. All soccer positions significantly (P<0.05) improved their performance in the experimental group. However, in the control group only defenders improved significantly (P<0.05) the sprint time. CONCLUSIONS: The use of static stretching at the end of the training sessions prevents the negative effect of the load on hamstring flexibility and it can influence improvement in flexibility.

Temporal activity in particular segments and transitions in the olympic triathlon.

The Olympic Triathlon is a combined endurance sport. It includes back-to-back swimming, cycling, running and the transition between events (T1 & T2). The aim of the current study was to analyse the possible relationship between the Lost Time T1 & T2 and overall performance. The results showed that the percentages of total time corresponding to each part of the race were: 16.2% for swimming, 0.74% for the swimming-cycling transition (T1), 53.07% for cycling, 0.47% for the cycling-running transition (T2) and 29.5% for running. The correlations between each part of the race and the final placing were: r=0.36 for swimming, r=0.25 for T1, r=0.62 for the cycling, r=0.33 for T2, and r=0.83 for the running. Also, values of r=0.34 & r=0.43 were obtained for Lost Time T1 and Lost Time T2, respectively. In conclusion, losing less time during T2 has been demonstrated to be related to obtaining a better final result.

Relationship between the talk test and ventilatory thresholds in well-trained cyclists.

The aim of this study was to extend the range of populations where the Talk Test (TT) might be used as a marker of physiologic thresholds. Eighteen highly trained cyclists underwent 2 incremental tests. One test included measurement of respiratory gas exchange to determine the ventilatory (VT) and respiratory compensation thresholds (RCTs). On a separate day, a TT was performed using the same exercise protocol. During TT, subjects read a standard paragraph at the end of each stage. The first stage at which the cyclists could not talk comfortably and could definitely not talk were referred to as the equivocal (EQ) and the negative stages (NEG), respectively. There were no significant differences in workload, heart rate, lactate, and rating of perceived exertion between VT (3.7 ± 0.4 W kg, 150 ± 10 b min, 1.6 ± 0.3 mm L, and 4.1 ± 1.4, respectively) vs. EQ (3.6 ± 0.4 W kg, 148 ± 12 b min, 1.3 ± 0.5 mm L, and 3.8 ± 1.2, respectively) and RCT (5.3 ± 0.4 W kg, 177 ± 7 b min, 4.0 ± 0.9 mm L, and 7.2 ± 1.0, respectively) vs. NEG (5.3 ± 0.5 W kg, 176 ± 10 b min, 4.2 ± 1.3 mm L, and 6.8 ± 1.5, respectively). We found significant relationships (p < 0.01) between VT and EQ and RCT and NEG for workload (r = 0.86 and 0.94, respectively), heart rate (r = 0.79 and 0.92, respectively), and rating of perceived exertion (r = 0.79 and 0.88, respectively). In conclusion, the present study showed that the EQ and NEG stages of TT can be used as a simple and practical surrogate of the VT and RCT in highly trained cyclists.

Sitting time increases the overweight and obesity risk independently of walking time in elderly people from Spain.

INTRODUCTION: Obesity, defined as an excess of total body fat, is a matter of concern all over the world, and its prevalence is still increasing among elderly people. OBJECTIVES: To examine whether sedentary behaviour (hours sitting per day) is associated with higher risk of central obesity, overweight-obesity and overfat in a representative sample of non-institutionalized Spanish elderly population and if so, whether hours walking per day modified this association. STUDY DESIGN: A cross-sectional study in a sample of 3136 people ≥65 years of age. MAIN OUTCOMES MEASURES: Anthropometric measurements were obtained using standardized techniques and equipment. Active and sedentary behaviours were recorded by questionnaire. RESULTS: For both men and women, the higher prevalence of overweight-obesity, central obesity and overfat was found in those who spent sitting more than 4h per day and walk less than 1h, compared with those who spent sitting less than 4h per day and walk more than 1h (all p<0.001, except for central obesity in women). In men, more than 4h sitting per day was associated with 1.7-fold higher odds of having central obesity compared with those sitting less than 4h per day (p<0.01). In women, this sedentary behaviour increased the risk of overweight-obesity and overfat by 1.5 and 1.4, respectively (p<0.01). Age or time spent walking did not significantly change these results. CONCLUSION: Sitting time increases the risk of overweight-obesity and overfat in women and the risk of central obesity in men, independently of walking time.

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.

The rotor pedaling system improves anaerobic but not aerobic cycling performance in professional cyclists.

The aims of this study were to evaluate the effects of both noncircular (ROT) and conventional (CON) chainring systems on aerobic and anaerobic cycling performances of professional cyclists, while analyzing the influence of varying the crank angle of maximum crank arm length of ROT. Fifteen professional road cyclists performed both incremental and sub-maximal aerobic tests and the Wingate anaerobic test in the laboratory. There were no statistical differences between CON and ROT in the aerobic tests, even when the best ROT position (ROT+) was selected. However, in the anaerobic test, maximal (4.2-9.1%) and mean (0.7-4.7%) power outputs were higher in ROT (P < 0.05). These differences were greater when the ROT+ was selected (11.2 and 7.0%, respectively). Our findings suggest that ROT is able to improve anaerobic but not aerobic cycling performance in professional cyclists. Nevertheless, it must be adapted to each cyclist to ensure these improvements.

Does intermittent hypoxia increase erythropoiesis in professional cyclists during a 3-week race?

In this study we examined the effects of intermittent hypoxia exposure (IHE) in a group of professional cyclists (n = 6; age 26 +/- 1 yr) competing in the 2001 Vuelta a España. After each daily stage, treated subjects received four 5-min bouts of normobaric IHE (mean O2 concentration of 12.6%, simulating a mean altitude of 4,000 m) interspersed with 5-min bouts of breathing hotel room air (normoxia) until completing a total IHE of 20-min duration. The primary outcome, compared to a control group of similar characteristics not receiving IHE (n = 5; age 25 +/- 1 yr), was the % increase in erythropoietin (Epo) from the beginning to the end of the Vuelta. Statistical analysis showed that Epo increase tended to be higher (p = 0.052) in the IHE group than in controls (37.4 +/- 5.8% vs. -4.4 +/- 19.5%, respectively). However IHE had no effect on reticulocytes or erythrocyte count (p > 0.05).

Urinary levels of 8-hydroxydeoxyguanosine as a marker of oxidative damage in road cycling.

We have determined the urinary 8-hydroxydeoxyguanosine (8-OHdG) levels of eight professional cyclists during a 4-day and a 3-week stage races. Monitoring of heart rates was used to establish zones corresponding to different intensities of exercise. The urinary 8-OHdG excretion, expressed by body weight, increased significantly in the first day or the first week of each race, respectively, and did not show further increases thereafter. Maximum 8-OHdG levels were reached in parallel to longer times spent at high intensities of exercise. Urinary excretion of creatinine increased with exercise, and changes in 8-OHdG levels were not detected when corrected by creatinine excretion. Serum glutathione concentrations did not change significantly at any point during exercise. We conclude that road cycling courses with an oxidative damage to DNA, which is sustained as long as the exercise is repeated. Both adaptation of antioxidant defenses and a decreased capacity to maintain a high intensity of effort may contribute to explain the absence of progressive increases in 8-OHdG excretion. The results of this study also confirm that the correction procedure using the amount of creatinine excreted should not be used when studying effects of exercise on urinary 8-OHdG.