Jose A. Rodríguez-Marroyo

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.

Rearfoot striking runners are more economical than midfoot strikers.

PURPOSE This study aimed to analyze the influence of foot strike pattern on running economy and biomechanical characteristics in subelite runners with a similar performance level. METHODS Twenty subelite long-distance runners participated and were divided into two groups according to their foot strike pattern: rearfoot (RF, n = 10) and midfoot (MF, n = 10) strikers. Anthropometric characteristics were measured (height, body mass, body mass index, skinfolds, circumferences, and lengths); physiological (VO2max, anaerobic threshold, and running economy) and biomechanical characteristics (contact and flight times, step rate, and step length) were registered during both incremental and submaximal tests on a treadmill. RESULTS There were no significant intergroup differences in anthropometrics, VO2max, or anaerobic threshold measures. RF strikers were 5.4%, 9.3%, and 5.0% more economical than MF at submaximal speeds (11, 13, and 15 km·h respectively, although the difference was not significant at 15 km·h, P = 0.07). Step rate and step length were not different between groups, but RF showed longer contact time (P < 0.01) and shorter flight time (P < 0.01) than MF at all running speeds. CONCLUSIONS The present study showed that habitually rearfoot striking runners are more economical than midfoot strikers. Foot strike pattern affected both contact and flight times, which may explain the differences in running economy.

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.

Workload demands in professional multi-stage cycling races of varying duration

Objetive: To analyse and compare the workload exerted by professional cyclists in 5-day, 8-day and 21-day stage races (5-SR, 8-SR, 21-SR). Methods: The study subjects were 30 professional cyclists competing in 10 5-SR, 5 8-SR and 5 21-SR. Heart rate (HR) was measured during the races and categorised into three intensity zones: Z1 (below the ventilatory threshold (VT)), Z2 (between VT and the respiratory compensation threshold (RCT)) and Z3 (above RCT). The training impulse (TRIMP) was calculated by multiplying the sum of the time spent in each zone by 1, 2 and 3, respectively. Monotony (average TRIMP/SD) and strain (total TRIMP×monotony) were also calculated for each race type. Results: The average time spent in Z3 during each stage was significantly (p<0.05) higher for 5-SR (∼31 min) and 8-SR (∼28 min) than for 21-SR (∼14 min). Daily TRIMP values in 5-SR (∼400) and 8-SR (∼395) were also higher than in 21-SR (∼370). Monotony was similar across races (∼3) but strain was about three times higher for 21-SR than for 5-SR and 8-SR. Conclusions: The cyclists’ effort by stage was less for 21-SR than for 5-SR and 8-SR. Competition strain and monotony accumulated during longer races influence the choice of strategies adopted by cyclists. It is likely that the intensity of each stage is modulated by total race duration, with longer races averaging the lowest daily workload.

Intensity of Exercise according to Topography in Professional Cyclists

PURPOSE The aim of the study was to analyze the intensity of effort made by professional cyclists in the different mountain passes climbed during the 1999 and 2000 Vuelta a España. METHODS During the ascent of high mountain passes of different categories (special category (HMS), and 1st (HM1), 2nd (HM2), and 3rd category (HM3)), the response of the HR was analyzed according to three intensity zones: zone 1(Z1, above the ventilatory threshold (VT)), zone 2 (Z2, between VT and the respiratory compensation threshold (RCT)), and zone 3 (Z3, above the RCT). RESULTS The values are presented as mean +/- SEM. Values of HR were significantly higher (P < 0.05) in HM1 (160 +/- 1 beats x min-1) compared with the other types of ascents. When we compared the different passes, the intensity decreased in the following order: HM1, HMS, HM2, and HM3. The average time that cyclists spent in Z3 was significantly higher in HM1 (10.7 +/- 1.4 min) with respect to the other categories. The time in Z2 was significantly higher in HMS and HM1 (43.1 +/- 1.5 and 44.3 +/- 3.1 min) than in HM2 and HM3 (21.6 +/- 1.1 and 11.9 +/- 1.1 min). The percentage of total time spent in Z3 was significantly higher in HM1 and HM3 (21.2 +/- 2.9 and 17.3 +/- 1.9%) than in HME and HM2. CONCLUSION The ascent of mountain passes is an activity involving intense effort which is reflected in the time cyclists spend in Z3 and Z2, and is related to the category of the mountain passes involved.

Comparison of Heart Rate and Session Rating of Perceived Exertion Methods of Defining Exercise Load in Cyclists

Abstract Rodríguez-Marroyo, JA, Villa, G, García-López, J, and Foster, C. Comparison of heart rate and session rating of perceived exertion methods of defining exercise load in cyclists. J Strength Cond Res 26(8): 2249–2257, 2012—The aim of this study was to analyze the competition load using the session rating of perceived exertion (RPE) during different professional cycling races and to assess its validity using the competition load based on heart rate (HR). During 2 consecutive seasons, 12 professional cyclists (mean ± SEM: age 25 ± 1 years, height 175 ± 3 cm, body mass 65.9 ± 2.0 kg, and V[Combining Dot Above]O2max 78.5 ± 1.7 ml·kg−1·min−1) competed in 5-, 7-, and 21-day cycling races. The HR response and session RPE were measured during the races to calculate the competition load based on the training impulse of the HR (TRIMPHR) and RPE data (TRIMPRPE). The highest (p < 0.05) TRIMPRPE was observed in 21-day races. However, the higher (p < 0.05) TRIMPHR was found in 5- and 7-day races. When TRIMPHR and TRIMPRPE were normalized by competing distance, neither TRIMPHR·km−1 nor TRIMPRPE·km−1 was significantly different between the analyzed cycling races. We found significant (p < 0.001) correlations between TRIMPHR and TRIMPRPE (r = 0.75) and between TRIMPHR·km−1 and TRIMPRPE·km−1 (r = 0.90). In conclusion, this study showed that the session RPE can be used to quantify the competition load during professional cycling races. This method can be a useful and noninvasive tool for coaches to monitor and control the training load in cyclists.

Actividad física y factores de riesgo cardiovascular de niños españoles de 11-13 años

INTRODUCTION AND OBJECTIVES The prevalence of childhood obesity has increased in recent decades. The aim was to determine whether a 3-month intervention on daily physical activity at school could affect body weight and cardiovascular risk factors associated with childhood obesity. METHODS A total of 137 children (12[1] years old) volunteered to participate in an observational cross-sectional study. Children were allowed to join one of the following groups: a) sedentary group (2h/week of physical education at school); b) active group (2h/week of physical education at school plus 3h/week extra physical activity), and c) sports group (2h/week of physical education at school plus 5h/week extra physical activity). Anthropometric characteristics, blood pressure, physical condition (estimated by the Course-Navette test), and biochemical parameters related with cardiovascular risk factors were determined. RESULTS Body weight, body mass index, waist circumference, sum of skinfold thickness, body fat percentage, and fat mass index of children were decreased with high physical activity level, whereas body water content significantly increased with activity. Parameters related with cardiovascular risk -triglycerides, insulin, systolic blood pressure, and homeostatic model assessment index- presented lower values in the sports group. Maximal oxygen uptake and maximum heart rate (Course Navette test) progressively increased with activity. Children participating in a total of 7h/week of physical activity presented significantly lower odds ratio of having high levels of the following cardiovascular risk factors: waist circumference, fat mass index, and homeostatic model assessment index. CONCLUSIONS Physical activity is important for metabolic health in children. Children with higher levels of physical activity presented better anthropometric and biochemical profiles.

Relationship Between the Talk Test and Ventilatory Thresholds in Well-Trained Cyclists

Abstract Rodríguez-Marroyo, JA, Villa, JG, García-López, J, and Foster, C. Relationship between the Talk Test and ventilatory thresholds in well-trained cyclists. J Strength Cond Res 27(7): 1942–1949, 2013—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−1, 150 ± 10 b·min−1, 1.6 ± 0.3 mm·L−1, and 4.1 ± 1.4, respectively) vs. EQ (3.6 ± 0.4 W·kg−1, 148 ± 12 b·min−1, 1.3 ± 0.5 mm·L−1, and 3.8 ± 1.2, respectively) and RCT (5.3 ± 0.4 W·kg−1, 177 ± 7 b·min−1, 4.0 ± 0.9 mm·L−1, and 7.2 ± 1.0, respectively) vs. NEG (5.3 ± 0.5 W·kg−1, 176 ± 10 b·min−1, 4.2 ± 1.3 mm·L−1, 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.

Harmonization process and reliability assessment of anthropometric measurements in the elderly EXERNET multi-centre study.

Background The elderly EXERNET multi-centre study aims to collect normative anthropometric data for old functionally independent adults living in Spain. Purpose To describe the standardization process and reliability of the anthropometric measurements carried out in the pilot study and during the final workshop, examining both intra- and inter-rater errors for measurements. Materials and Methods A total of 98 elderly from five different regions participated in the intra-rater error assessment, and 10 different seniors living in the city of Toledo (Spain) participated in the inter-rater assessment. We examined both intra- and inter-rater errors for heights and circumferences. Results For height, intra-rater technical errors of measurement (TEMs) were smaller than 0.25 cm. For circumferences and knee height, TEMs were smaller than 1 cm, except for waist circumference in the city of Cáceres. Reliability for heights and circumferences was greater than 98% in all cases. Inter-rater TEMs were 0.61 cm for height, 0.75 cm for knee-height and ranged between 2.70 and 3.09 cm for the circumferences measured. Inter-rater reliabilities for anthropometric measurements were always higher than 90%. Conclusion The harmonization process, including the workshop and pilot study, guarantee the quality of the anthropometric measurements in the elderly EXERNET multi-centre study. High reliability and low TEM may be expected when assessing anthropometry in elderly population.

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

Rodríguez-Marroyo, JA, Pernía, R, Cejuela, R, García-López, J, Llopis, J, and Villa, JG. Exercise intensity and load during different races in youth and junior cyclists. J Strength Cond Res 25(2): 511-519, 2011-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.