Cristina Blasco-Lafarga

Pedaling power and speed production vs. technical factors and track difficulty in bicycle motocross cycling.

Mateo, M, Blasco-Lafarga, C, and Zabala, M. Pedaling power and speed production vs. technical factors and track difficulty in BMX cycling. J Strength Cond Res 25(12): 3248–3256, 2011—This article analyzes whether there is a determined profile in the production of cyclic and acyclic periods in relation to the phases of a bicycle motocross (BMX) race and whether this profile is related to the variables, Difficulty of track and Techniques used. After an initial test for determining maximum pedaling power (Pmax), 9 athletes belonging to the Spanish national team completed 3 series of 3 different types of races: (a) Complete track without pedaling; (b) Track, pedaling only at the gate start; and (c) track with free pedaling. The triple test was carried out over 3 days and on different level tracks: (a) high difficulty (HD), (b) medium difficulty (MD), and (c) low difficulty (LD). Our results show that average peak power applied in the BMX race was 85.21 ± 2.15% Pmax, coming down to 73.02 ± 18.38% at the gate start and to 51.37 ± 15.84% on the first straight. On the other hand, mean power (MP) in the BMX race is 33.79 ± 8.60% MPmax, with statistically significant differences in relation to the difficulty of the track (p < 0.000; 0.009; higher in the easiest). The mean velocity developed is 34.21 ± 1.0 km·h−1 with significant differences (p < 0.000) in relation to the difficulty of the track. Acyclic efforts accounted for 86.3%, and cyclic efforts accounted for the remaining 16.7% of the overall performance in the race, with differences in relation to the difficulty of the track (p ≤ 0.003). Both power profile and performance (measured as velocity) are dependent on the phases and techniques of the race and are significantly affected by the level of difficulty of the track. The greater the technical level of the track, the lesser the possibility of developing cyclic power and vice versa.

Skinfold Sum: Reference Values for Top Athletes

Las determinaciones de los pliegues subcutaneos de diferentes zonas corporales son utilizadas ocasionalmente en ecuaciones predictivas para calcular la masa grasa. Este es un parametro critico que condiciona el optimo rendimiento deportivo. No existen valores de referencia de pliegues subcutaneos en atletas de elite. Por tanto, el principal objetivo de este estudio es presentar valores de referencia de pliegues subcutaneos de una amplia poblacion de atletas. Los pliegues tricipital, subescapular, suprailiaco, abdominal, muslo y pierna fueron medidos de acuerdo a la normativa ISAK (Sociedad Internacional para el Avance de la Cineantropometria) en 2500 atletas. La suma de los seis pliegues asi como las sumas parciales de diferentes segmentos corporales (superior, troncal e inferior) fueron calculadas. Los datos muestran que los valores mas altos de pliegues subcutaneos fueron observados en el muslo y zona abdominal, siendo el pliegue subescapular el menor. Las mujeres presentaron valores mas altos de pliegues subcutaneos que los hombres. Respecto a las sumas parciales, los segmentos corporales troncal e inferior presentaron las mayores puntuaciones. Los practicantes de hockey, balonmano, futbol sala, remo, submarinismo y tenis de mesa mostraron los mayores porcentajes de grasa. En conclusion, los calculos de masa grasa en atletas deberian de considerar el sumatorio de los seis pliegues subcutaneos. Ademas, la grasa corporal tiende a estar localizada en los segmentos corporales troncal e inferior y varia segun el genero y la disciplina deportiva.

Is baseline cardiac autonomic modulation related to performance and physiological responses following a supramaximal Judo test

Little research exists concerning Heart Rate (HR) Variability (HRV) following supramaximal efforts focused on upper-body explosive strength-endurance. Since they may be very demanding, it seems of interest to analyse the relationship among performance, lactate and HR dynamics (i.e. HR, HRV and complexity) following them; as well as to know how baseline cardiac autonomic modulation mediates these relationships. The present study aimed to analyse associations between baseline and post-exercise HR dynamics following a supramaximal Judo test, and their relationship with lactate, in a sample of 22 highly-trained male judoists (20.70±4.56 years). A large association between the increase in HR from resting to exercise condition and performance suggests that individuals exerted a greater sympathetic response to achieve a better performance (Rating of Perceived Exertion: 20; post-exercise peak lactate: 11.57±2.24 mmol/L; 95.76±4.13 % of age-predicted HRmax). Athletes with higher vagal modulation and lower sympathetic modulation at rest achieved both a significant larger ∆HR and a faster post-exercise lactate removal. A enhanced resting parasympathetic modulation might be therefore related to a further usage of autonomic resources and a better immediate metabolic recovery during supramaximal exertions. Furthermore, analyses of variance displayed a persistent increase in α1 and a decrease in lnRMSSD along the 15 min of recovery, which are indicative of a diminished vagal modulation together with a sympathovagal balance leaning to sympathetic domination. Eventually, time-domain indices (lnRMSSD) showed no lactate correlations, while nonlinear indices (α1 and lnSaEn) appeared to be moderate to strongly correlated with it, thus pointing to shared mechanisms between neuroautonomic and metabolic regulation.

Desaturation Patterns Detected by Oximetry in a Large Population of Athletes

Optimal exercise performance in well trained athletes can be affected by arterial oxygen saturation failure. Noninvasive detection of this phenomenon when performing a routine ergometric test can be a valuable tool for subsequent planning of the athletes training, recovery, and nutrition. Oximetry has been used to this end. The authors studied 339 athletes performing a similar exercise trial under well controlled environmental conditions. Maximum speed, oxygen uptake, and heart rate levels were simultaneously measured. From the obtained data, six patterns were found: (a) athletes in whom oxygen saturation is constant (≥ 95%) during test execution; (b) athletes displaying a progressive desaturation with incremental exercise intensities; (c) athletes presenting a transient desaturation in the anaerobic threshold region; (d) athletes starting with a mild-to-moderate desaturation at the beginning of the test, but reaching normal saturation values at the end; (e) athletes displaying mild-to-moderate desaturation levels throughout the whole test; and (f) athletes displaying a transient desaturation in the anaerobic threshold region and a new desaturation at the end of the test. In conclusion, it is believed that establishment of desaturation patterns by validated oximetry could be a first approach to evaluate the adaptation of the cardiorespiratory system to exercise intensity, helping to improve results.

Cardiovascular and Autonomic Responses to a Maximal Exercise Test in Elite Youngsters

To analyze cardiovascular and autonomic responses in elite youngsters, 13 male cyclists (15.43±0.51 years) performed a graded-test until voluntary exhaustion. Oxygen consumption (VO2), blood lactate (BLa), arterial oxygen saturation (SaO2), respiratory exchange ratio (RER) and rating of perceived exertion (RPE) were collected, while heart rate (HR) was registered for heart rate variability (HRV) analyses, looking for linear and nonlinear comparisons. Cyclists reached maximal exertion [RPE: 19.14±0.94; BLa: 8.92±2.51 mmol.L-1; RER: 1.04±0.03; SaO2: 92.43±2.5%] and high-level performance (4.41±0.46 W·Kg-1; 60.77±6.87 ml·Kg·min-1) once over 95% of age-predicted HRmax. VO2 and RPE increased, and RR intervals (RRi) decreased (p<0.005), whereas only the short-term scaling exponent of the Detrended Fluctuation Analysis technique (DFA1) displayed similar adaptive changes regarding intensity (p=0.011). After controlling for W·Kg-1 and RRi, DFA1100% (0.260±0.084) showed large-negative correlations with VO2max (r=-0.83; p<0.05) and RPEmax (r=-0.79; p<0.05), suggesting a strong association between the reduction in self-similar properties of the cardiac signal and the capacity to elicit at maximum in youths. Overall-HRV (lnRMSSD) and short-term variability (lnSD1) did not show any association at maximum, or significant differences regarding intensity. DFA1 might reflect ANS-CNS linkage related to cardiac respiratory controls through exercise, becoming a complementary criterion for VO2max testing in youths.

Six hundred meter-run and broken 800's contribution to pacing improvement in eight hundred meter-athletics: role of expertise and training implications.

Abstract Blasco-Lafarga, C, Montoya-Vieco, A, Martínez-Navarro, I, Mateo-March, M, and Gallach JE. Six hundred meter–run and broken 800’s contribution to pacing improvement in eight hundred meter–athletics: role of expertise and training implications. J Strength Cond Res 27(9): 2405–2413, 2013—Little is known about the influence of speed endurance workouts on the improvement of pacing strategies in the 800-m running event. This study aims to analyze it, comparing continuous repetitions vs. interval training workouts. Because we hypothesize that pacing is susceptible to expertise, there might be age differences. Nineteen male 800-m runners (age: 21.36 ± 5.26, season best [SB]: 117.14 ± 5.18 seconds) were tested. Athletes were asked to run 1 × 600 m (6r) at 100% (SB) and 2 × 4 (200 m per 30 seconds) per 15 minutes (B8) at 102% (SB), counterbalanced and randomized within 1 week of difference. Pacing strategy (velocity dynamics) was analyzed by means of time differences in 200-m segments (T200), whereas age category was considered a grouping factor (younger than 23 years–senior, n = 10; vs. juvenile-junior, n = 9; 25.29 ± 4.32, 17.00 ± 0.66 years). Blood lactate was registered after 6r, B81, and B82 bouts. Univariate contrast analysis revealed a significant decrease in velocity during 6r (p < 0.001; 9.33% between first and third segment), thus a positive pacing, whatever the age category. B8 shared this final significant impairment (p < 0.001), although it was smaller (5.73% drop for B81; 8.47% for B82), and neither linear nor significant among consecutive T200. B8 also showed significant differences (p < 0.05) in the interaction sampling condition × age category. The T test added blood lactate significant differences (B82: 15.42 ± 1.16, B81: 12.25 ± 2.03 and 6r: 13.58 ± 1.82 mmol·L-1). Summarizing, both methods share a positive pacing, confirming to be related to enhancing energy systems and coping final fatigue in the 800 m. Continuous 6r preserves the nature and tempo of the 800 m, although 1 repetition is metabolically limited. Interval B8 allows larger amounts of high intensity running, enhancing neuromuscular benefits jointly with higher lactate productions. Significant age category differences in B8 indicate that pacing capacity may improve with expertise and interval workouts may be appropriate methods to manage it.