Fernando Pareja-Blanco

Bio: Fernando Pareja-Blanco is an academic researcher from Pablo de Olavide University. The author has contributed to research in topics: Sprint & Medicine. The author has an hindex of 18, co-authored 69 publications receiving 1325 citations.

Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations

Abstract: We compared the effects of two resistance training (RT) programs only differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40) on muscle structural and functional adaptations. Twenty-two young males were randomly assigned to a VL20 (n = 12) or VL40 (n = 10) group. Subjects followed an 8-week velocity-based RT program using the squat exercise while monitoring repetition velocity. Pre- and post-training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross-sectional area (CSA) and fiber type analyses, one-repetition maximum strength and full load-velocity squat profile, countermovement jump (CMJ), and 20-m sprint running. VL20 resulted in similar squat strength gains than VL40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL40, whereas it was preserved in VL20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.

Effect of movement velocity during resistance training on neuromuscular performance.

Abstract: This study aimed to compare the effect on neuromuscular performance of 2 isoinertial resistance training programs that differed only in actual repetition velocity: maximal intended (MaxV) vs. half-maximal (HalfV) concentric velocity. 21 resistance-trained young men were randomly assigned to a MaxV (n=10) or HalfV (n=11) group and trained for 6 weeks using the full squat exercise. A complementary study (n=8) described the acute metabolic and mechanical response to the protocols used. MaxV training resulted in a likely more beneficial effect than HalfV on squat performance: maximum strength (ES: 0.94 vs. 0.54), velocity developed against all (ES: 1.76 vs. 0.88), light (ES: 1.76 vs. 0.75) and heavy (ES: 2.03 vs. 1.64) loads common to pre- and post-tests, and CMJ height (ES: 0.63 vs. 0.15). The effect on 20-m sprint was unclear, however. Both groups attained the greatest improvements in squat performance at their training velocities. Movement velocity seemed to be of greater importance than time under tension for inducing strength adaptations. Slightly higher metabolic stress (blood lactate and ammonia) and CMJ height loss were found for MaxV vs. HalfV, while metabolite levels were low to moderate for both conditions. MaxV may provide a superior stimulus for inducing adaptations directed towards improving athletic performance.

Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training.

Abstract: The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m · s(-1) (∼ 60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤ 0.80 m · s(-1)). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.

Physiological and methodological aspects of rate of force development assessment in human skeletal muscle.

Abstract: Rate of force development (RFD) refers to the ability of the neuromuscular system to increase contractile force from a low or resting level when muscle activation is performed as quickly as possible, and it is considered an important muscle strength parameter, especially for athletes in sports requiring high-speed actions. The assessment of RFD has been used for strength diagnosis, to monitor the effects of training interventions in both healthy populations and patients, discriminate high-level athletes from those of lower levels, evaluate the impairment in mechanical muscle function after acute bouts of eccentric muscle actions and estimate the degree of fatigue and recovery after acute exhausting exercise. Notably, the evaluation of RFD in human skeletal muscle is a complex task as influenced by numerous distinct methodological factors including mode of contraction, type of instruction, method used to quantify RFD, devices used for force/torque recording and ambient temperature. Another important aspect is our limited understanding of the mechanisms underpinning rapid muscle force production. Therefore, this review is primarily focused on (i) describing the main mechanical characteristics of RFD; (ii) analysing various physiological factors that influence RFD; and (iii) presenting and discussing central biomechanical and methodological factors affecting the measurement of RFD. The intention of this review is to provide more methodological and analytical coherency on the RFD concept, which may aid to clarify the thinking of coaches and sports scientists in this area.

Effects of velocity-based resistance training on young soccer players of different ages.

Abstract: This study aimed to analyze the effect of velocity-based resistance training (RT) with moderate loads and few repetitions per set combined with jumps and sprints on physical performance in young soccer players of different ages. A total of 44 elite youth soccer players belonging to 3 teams participated in this study: an under-16 team (U16, n = 17) and an under-18 team (U18, n = 16) performed maximal velocity RT program for 26 weeks in addition to typical soccer training, whereas an under-21 team (U21, n = 11) did not perform RT. Before and after the training program, all players performed 20-m running sprint (T20), countermovement jump (CMJ), a progressive isoinertial loading test in squat to determine the load that elicited a ∼ 1 m · s(-1) velocity (V1LOAD) and an incremental field test to determine maximal aerobic speed (MAS). U16 showed significantly (p = 0.000) greater gains in V1LOAD than U18 and U21 (100/0/0%). Only U16 showed significantly (p = 0.01) greater gains than U21 (99/1/0%) in CMJ height. U18 obtained a likely better effect on CMJ performance than U21 (89/10/1%). The beneficial effects on T20 between groups were unclear. U16 showed a likely better effect on MAS than U21 (80/17/3%), whereas the rest of comparisons were unclear. The changes in CMJ correlated with the changes in T20 (r = -0.49) and V1LOAD (r = 0.40). In conclusion, velocity-based RT with moderate load and few repetitions per set seems to be an adequate method to improve physical performance in young soccer players.

The Environmental Protection Agency

Abstract: The Environmental Protection Agency (EPA) provides access to information on a variety of topics related to the environment and strives to inform citizens of health risks. The EPA also has an extensive library network that consists of 26 libraries throughout the United States, which provide access to a plethora of information to EPA employees, scientists, and researchers. The EPA implemented a reorganization project to digitize their materials so they would be more accessible to a wider range of users, but this plan was drastically accelerated when the EPA was threatened with a budget cut. It chose to close and reduce the hours and services of some of their libraries. As a result, the agency was accused of denying users the “right to know” by making information unavailable, not providing an adequate strategic plan, and discarding vital materials. This case study explores the background of the digitization project, the practices implemented, and the critiques of the project.

Physical demands of different positions in FA Premier League soccer

Abstract: The purpose of this study was to evaluate the physical demands of English Football Association (FA) Premier League soccer of three different positional classifications (defender, midfielder and striker). Computerised time-motion video-analysis using the Bloomfield Movement Classification was undertaken on the purposeful movement (PM) performed by 55 players. Recognition of PM had a good inter-tester reliability strength of agreement (κ = 0.7277). Players spent 40.6 ± 10.0% of the match performing PM. Position had a significant influence on %PM time spent sprinting, running, shuffling, skipping and standing still (p 0.05). Players spent 48.7 ± 9.2% of PM time moving in a directly forward direction, 20.6 ± 6.8% not moving in any direction and the remainder of PM time moving backward, lateral, diagonal and arced directions. The players performed the equivalent of 726 ± 203 turns during the match; 609 ± 193 of these being of 0° to 90° to the left or right. Players were involved in the equivalent of 111 ± 77 on the ball movement activities per match with no significant differences between the positions for total involvement in on the ball activity (p > 0.05). This study has provided an indication of the different physical demands of different playing positions in FA Premier League match-play through assessment of movements performed by players.

Trends Supporting the In-Field Use of Wearable Inertial Sensors for Sport Performance Evaluation: A Systematic Review

Abstract: Recent technological developments have led to the production of inexpensive, non-invasive, miniature magneto-inertial sensors, ideal for obtaining sport performance measures during training or competition. This systematic review evaluates current evidence and the future potential of their use in sport performance evaluation. Articles published in English (April 2017) were searched in Web-of-Science, Scopus, Pubmed, and Sport-Discus databases. A keyword search of titles, abstracts and keywords which included studies using accelerometers, gyroscopes and/or magnetometers to analyse sport motor-tasks performed by athletes (excluding risk of injury, physical activity, and energy expenditure) resulted in 2040 papers. Papers and reference list screening led to the selection of 286 studies and 23 reviews. Information on sport, motor-tasks, participants, device characteristics, sensor position and fixing, experimental setting and performance indicators was extracted. The selected papers dealt with motor capacity assessment (51 papers), technique analysis (163), activity classification (19), and physical demands assessment (61). Focus was placed mainly on elite and sub-elite athletes (59%) performing their sport in-field during training (62%) and competition (7%). Measuring movement outdoors created opportunities in winter sports (8%), water sports (16%), team sports (25%), and other outdoor activities (27%). Indications on the reliability of sensor-based performance indicators are provided, together with critical considerations and future trends.

Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations

Abstract: We compared the effects of two resistance training (RT) programs only differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40) on muscle structural and functional adaptations. Twenty-two young males were randomly assigned to a VL20 (n = 12) or VL40 (n = 10) group. Subjects followed an 8-week velocity-based RT program using the squat exercise while monitoring repetition velocity. Pre- and post-training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross-sectional area (CSA) and fiber type analyses, one-repetition maximum strength and full load-velocity squat profile, countermovement jump (CMJ), and 20-m sprint running. VL20 resulted in similar squat strength gains than VL40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL40, whereas it was preserved in VL20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.

Effectiveness of an Individualized Training Based on Force-Velocity Profiling during Jumping

Abstract: Ballistic performances are determined by both the maximal lower limb power output (Pmax) and their individual force-velocity (F-v) mechanical profile, especially the F-v imbalance (FVimb): difference between the athlete’s actual and optimal profile. An optimized training should aim to increase Pmax and/or reduce FVimb. The aim of this study was to test whether an individualized training program based on the individual F-v profile would decrease subjects’ individual FVimb and in turn improve vertical jump performance. FVimb was used as the reference to assign participants to different training intervention groups. 84 subjects were assigned to three groups: an “optimized” group divided into velocity-deficit, force-deficit and well-balanced sub-groups based on subjects’ FVimb, a “non-optimized” group for which the training program was not specifically based on FVimb and a control group. All subjects underwent a 9-week specific resistance training program. The programs were designed to reduce FVimb for the optimized groups (with specific programs for sub-groups based on individual FVimb values), while the non-optimized group followed a classical program exactly similar for all subjects. All subjects in the three optimized training sub-groups (velocity-deficit, force-deficit and well-balanced) increased their jumping performance (12.7±5.7% ES= 0.93±0.09, 14.2±7.3% ES= 1.00±0.17, and 7.2±4.5% ES= 0.70±0.36 respectively) with jump height improvement for all subjects, whereas the results were much more variable and unclear in the non-optimized group. This greater change in jump height was associated with a markedly reduced FVimb for both force-deficit (57.9±34.7% decrease in FVimb) and velocity-deficit (20.1±4.3%) subjects, and unclear or small changes in Pmax (-0.40±8.4% and +10.5±5.2%, respectively). An individualized training program specifically based on FVimb (gap between the actual and optimal F-v profiles of each individual) was more efficient at improving jumping performance (i.e. unloaded squat jump height) than a traditional resistance training common to all subjects regardless of their FVimb. Although improving both FVimb and Pmax has to be considered to improve ballistic performance, the present results showed that reducing FVimb without even increasing Pmax lead to clearly beneficial jump performance changes. Thus, FVimb could be considered as a potentially useful variable for prescribing optimal resistance training to improve ballistic performance.