Juan García-López

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.

Influence of Saddle Height on Lower Limb Kinematics in Well-trained Cyclists: Static Vs. Dynamic Evaluation in Bike Fitting

Abstract Ferrer-Roca, V, Roig, A, Galilea, P, and García-López, J. Influence of saddle height on lower limb kinematics in well-trained cyclists: Static vs. dynamic evaluation in bike fitting. J Strength Cond Res 26(11): 3025–3029, 2012—In cycling, proper saddle height is important because it contributes to the mechanical work of the lower limb joints, thus altering pedaling efficiency. The appropriate method to select optimal saddle height is still unknown. This study was conducted to compare a static (anthropometric measurements) vs. a dynamic method (2D analysis) to adjust saddle height. Therefore, an examination of the relationship between saddle height, anthropometrics, pedaling angles, and hamstring flexibility was carried out. Saddle height outside of the recommended range (106–109% of inseam length) was observed in 56.5% of the subjects. Inappropriate knee flexion angles using the dynamic method were observed in 26% of subjects. The results of this study support the concept that adjusting saddle height to 106–109% of inseam length may not ensure an optimal knee flexion (30–40°). To solve these discrepancies, we applied a multiple linear regression to study the relationship between anthropometrics, pedaling angles, and saddle height. The results support the contention that saddle height, inseam length, and knee angle are highly related (R2 = 0.963, p < 0.001). We propose a novel equation that relates these factors to recommend an optimal saddle height (108.6–110.4% of inseam length).

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.

Physical exercise and improvement of liver oxidative metabolism in the elderly.

Abstract Drug metabolizing capacity is generally reduced in the elderly, and physical exercise has been reported to increase drug oxidative metabolism. The purpose of this investigation was to study the effects of engagement in a program of regular physical exercise on the clearance and metabolite excretion of antipyrine, a marker of oxidative metabolism, in elderly subjects. The saliva clearance of antipyrine and the production clearances of antipyrine metabolites were studied in 37 elderly women (mean age 66 years). Subjects attended 60-min sessions three times a week for 12 weeks. Each session consisted of both aerobic (training of cardiorespiratory capacity) and nonaerobic (training of muscular strength/endurance and flexibility/coordination) exercises performed at 50–75% of maximum oxygen uptake. Antipyrine was administered orally and pharmacokinetic parameters were obtained from saliva and urine samples. After 3 months of participation in the exercise program, salivary antipyrine clearance was significantly increased by 17% mean (SEM) 0.42 (0.02) vs 0.36 (0.02) ml/min/kg; P < 0.05) and the half-life of antipyrine was significantly reduced by 18% (17.9 (1.1) vs 22.3 (1.3) h; P < 0.05). No significant change with exercise was observed in the renal clearance of antipyrine or in the norantipyrine formation clearance, but significant increases were found for hydroxymethylantipyrine [42 (5) vs 32 (4) μl/kg/min; P < 0.05; +31%] and 4-hydroxyantipyrine [243 (18) vs 194 (17) μl/kg/min; P < 0.05; +25%] formation clearances. These findings indicate that regular exercise leads to increased disposition of antipyrine in the elderly and that the main metabolic pathways of the compound are changed differentially.

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.

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.

Acute effects of small changes in bicycle saddle height on gross efficiency and lower limb kinematics.

Abstract Ferrer-Roca, V, Bescós, R, Roig, A, Galilea, P, Valero, O and García-López, J. Acute effects of small changes in bicycle saddle height on gross efficiency and lower limb kinematics. J Strength Cond Res 28(3): 784–791, 2014—The aim of the present study was to assess the acute effects of small changes in bicycle saddle height on gross efficiency (GE) and lower-limb kinematics. Well-trained cyclists (n = 14) performed a submaximal pedaling test (∼70–75% of the v[Combining Dot Above]O2max) at constant cadence (90 rpm). It consisted of 3 randomized sets of 6 minutes with the preferred saddle height, 2% higher and 2% lower. Gross efficiency was significantly lower and oxygen consumption (v[Combining Dot Above]O2) was significantly higher when raising the saddle (GE = 19.9 ± 1.5%; V[Combining Dot Above]O2max = 43.8 ml·kg−1·min−1) than when lowering it (GE = 20.4 ± 1.3%; V[Combining Dot Above]O2 = 42.8 ml·kg−1·min−1). Additionally, a change of 0.8% in GE (20.6 ± 1.6% to 19.8 ± 1.6%, p < 0.05) was observed when comparing the positions where the best and worst GE was obtained. A significant effect of the small changes in saddle height on lower limb kinematics was also observed (p < 0.05). The differences between lower and higher saddle positions, in hip, knee, and ankle joints were an increase of extension (∼4, 7, and 8°, respectively), a decrease of flexion (∼3, 4, and 4°, respectively) and, consequently, an increase of the range of movement (∼1, 3, and 4°, respectively). The results of the present study indicate that small changes in saddle height affected GE and lower limb kinematics The observed changes in lower limb kinematics could justify, in part, the GE changes. Further research should evaluate long-term effects of these small modifications in the seat height on GE and lower limb kinematics.

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.

Differences in pedalling technique between road cyclists of different competitive levels

ABSTRACT The purpose of this study was to compare the pedalling technique in road cyclists of different competitive levels. Eleven professional, thirteen elite and fourteen club cyclists were assessed at the beginning of their competition season. Cyclists’ anthropometric characteristics and bike measurements were recorded. Three sets of pedalling (200, 250 and 300 W) on a cycle ergometer that simulated their habitual cycling posture were performed at a constant cadence (~90 rpm), while kinetic and kinematic variables were registered. The results showed no differences on the main anthropometric variables and bike measurements. Professional cyclists obtained higher positive impulse proportion (1.5–3.3% and P < 0.05), mainly due to a lower resistive torque during the upstroke (15.4–28.7% and P < 0.05). They also showed a higher ankle range of movement (ROM, 1.1–4.0° and P < 0.05). Significant correlations (P < 0.05) were found between the cyclists’ body mass and the kinetic variables of pedalling: positive impulse proportion (r = −0.59 to −0.61), minimum (r = −0.59 to −0.63) and maximum torques (r = 0.35–0.47). In conclusion, professional cyclists had better pedalling technique than elite and club cyclists, because they opted for enhancing pulling force at the recovery phase to sustain the same power output. This technique depended on cycling experience and level of expertise.

Differences in Spatiotemporal Parameters Between Trained Runners and Untrained Participants

Abstract Gómez-Molina, J, Ogueta-Alday, A, Stickley, C, Tobalina, JC, Cabrejas-Ugartondo, J, and García-López, J. Differences in spatiotemporal parameters between trained runners and untrained participants. J Strength Cond Res 31(8): 2169–2175, 2017—The aim of this study was to compare the spatiotemporal parameters of trained runners and untrained participants with the same foot strike pattern (rearfoot) during running at controlled speeds. Twenty-one participants were classified in 2 groups according to their training experience: Trained (n = 10, amateur runners with long distance training experience) and Untrained (n = 11, healthy untrained participants). Anthropometric variables were recorded, and the participants performed both a submaximal (between 9 and 15 km·h−1) and a graded exercise running test (from 6 km·h−1 until exhaustion) on a treadmill. Physiological (V[Combining Dot Above]O2max, heart rate, running economy [RE], peak speed …) and biomechanical variables (contact and flight times, step rate, and length) were simultaneously registered. Trained runners showed higher step rate and shorter step length than the Untrained group at the same running speeds (between 4 and 7%, p ⩽ 0.05) and at the same physiological intensities (between 7 and 11%, p ⩽ 0.05). However, there were no differences in contact and flight times between groups. Significant differences (p ⩽ 0.05) and large effect sizes (Cohens d) between groups were found for body mass, sum of 6 skinfolds, V[Combining Dot Above]O2max, peak speed, and ventilatory threshold and respiratory compensation threshold speeds. The Trained group also showed a ∼7% better RE (ml·kg−0.75·km−1) than the Untrained group. In conclusion, adopting higher step rate and shorter step length may be an adaptive mechanism of the Trained group to reduce injury risk and possibly improve RE. However, contact and flight times were consistent regardless of training level.