Thought that I’ll start this thread to share with FORUM community some interesting stuff I have come across.
It would be great if we could provide links with short description.
Regards
wermouth
ExRx.net (Exercise Prescription on the Internet) is a free resource for the exercise professional, coach, or fitness enthusiast featuring comprehensive exercise libraries (>1400 exercises), fitness assessment calculators, and reference articles.
http://www.exrx.net/index.html
Journal of Applied Physiology.
The Journal of Applied Physiology publishes original papers that deal with diverse areas of research in applied physiology. Most of the papers are free and if somebody wants to improve their knowledge about EMS, energy systems, physiological systems, adaptation etc… in my opinion this is the website to see.
http://jap.physiology.org/search?fulltext=&submit=yes&x=6&y=11
Article: Muscle Genes and Athletics Performance
The cellular biology of muscle helps to explain why a particular athlete wins and suggests what future athletes might do to better their odds.
by Jesper L. Andersen, Peter Schjerling and Bengt Saltin
http://me.umn.edu/labs/hmd/lab/docs/muscle-genes.pdf
wermouth
Newtonian Model of an Elite Sprinter: How Much Force do Athletes Need to Produce Each Step to be World Class?
by Jeremy Richmond
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A model is presented of the force and power produced during a world record sprint to provide coaches and athletes with a method to determine ho[SIZE=2][FONT=verdana]w much force to use during strength training and what velocity to train at. In addition to specific velocity of strength training, the coach or athlete can estimate the biomechanical position of the athlete by determining that position for the relevant step so that training can be specific to the movement pattern of actual sprinting. The model is determined by using empirical data to develop relationships between the variables of time, velocity, instantaneous velocity, contact time and distance travelled over each individual step. The formula used for the Newtonian model is applied to an athlete, Matic Osovnikar, and shows weakness in the strength of one particular leg above a certain velocity during steps 6, 8 and 10. The lack of force produced by that leg results in negative velocity of the athlete during steps 8 and 10. From the comparison of data from Matic Osovnikar with the Newtonian model, a suggestion is for the athlete to undertake velocity specific and movement specific strength training of that leg to improve performance during steps 6, 8 and 10. This may improve the overall sprint performance for the athlete.
http://www.elitetrack.com/article_files/newtonian-sprinting.pdf
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Biomechanics Of Sprint Running: A Methodological Contribution
Elena Bergamini
ABSTRACT
The continued increase in running popularity has prompted a comparable explosion of research in the last decades. This has been further potentiated by recent technical and technological advancements. The current state of knowledge about the major findings in sprint running biomechanics is presented and a brief overview of the current technologies used in the assessment of running is provided. Many variables have been studied pertaining to the different phases of sprint running. Significant factors include: technique, electromyographic activity, kinematics and kinetics. Sprint technique has been analysed during the block start, acceleration and maintenance phases. The EMG activity pattern of the main muscles is described in the literature, but there Is a need of further investigation, particularly for highly skilled sprinters. The reaction time of good athletes is short, but it does not correlate with performance levels. The force-power production and the force impulse during the block start phase are key factors in order to generate high velocity. Nevertheless, they proved to correlate with the incidence of knee-related injuries. During acceleration and maintenance phases, the reduction of the horizontal braking forces and the maximisation of the propulsive forces are crucial in order not to decrease velocity. Leg and vertical stiffness are sensitive parameters for the optimization of performance and, at the same time, for the reduction of injury risk. Several external factors, as footwear, ground reaction surface and air resistance, may influence the athlete’s technique and performance. Efficient sprint running requires an optimal combination between the examined biomechanical variables and such factors. Interestingly, while a large number of studies focused the determinants of the performance, there is a general paucity of scientific works showing definitive relationships between either anatomical factors and injury, or biomechanical measures and injury during sprint running. As concerns technologies and methods for sprint running analysis, although traditional measurement devices such as motion capture systems, force plates, and electromyography are considered as the most accurate methods, they suffer from limitations, such as expense and lack of portability. Recent technological advances have made available more viable options such as accelerometers, electrogoniometers, gyroscopes, and in-shoe pressure sensors. Combined with wireless technology and/or data loggers, they appear to be an affordable, lightweight alternative to running analysis, allowing data collection over prolonged periods of time in almost any environment.
http://amsdottorato.cib.unibo.it/3541/1/bergamini_elena_tesi.pdf
ABSTRACT
Biomechanical investigations of sprint start technique and performance
N. E. Bezodis, University of Bath, 2009
The start is an important part of any athletics sprint event, and has thus been the focus of considerable biomechanical research. However, relatively little is known about how differences in technique beyond the ‘set’ position can influence the consequent performance levels. A series of empirical and theoretical investigations were therefore undertaken to advance the understanding in this area.
Initial investigations revealed the importance of appropriately quantifying performance. Horizontal external power production provided the most appropriate measure and was subsequently used to quantify the success associated with different aspects of technique. Block phase analyses of 13 trained and three international-level sprinters highlighted the importance of increasing hip extension and the rear leg push. It was revealed that over-extending the frontankle could impair performance due to an unfavourable increase in push duration. Empirical investigations of the first stance phase in international-level sprinters revealed the importance of configuration at touchdown - positioning the stance foot further behind the centre of mass and generating a large gravitational trunk-segment moment appeared beneficial for performance. Joint kinetics patterns were identified which assisted performance by augmenting horizontal centre of mass translation during stance.
To further investigate the first stance phase, a seven-segment angle-driven model was developed. Model evaluation revealed kinematic and kinetic outputs to match reality with a mean difference ranging from 5.2% to 11.1%. Individual-specific simulations identified alterations to stance leg angles at touchdown which influenced the centre of mass position and gravitational moment of the trunk, and consequently performance. Increases in the backwards velocity of the toe at touchdown and reductions in ankle dorsiflexion during early stance also improved performance by increasing the rate of horizontal force development. The combined empirical and theoretical understanding therefore highlighted several aspects of technique which could be altered in an attempt to improve sprint start performance.
http://opus.bath.ac.uk/17188/
BIOMECHANICAL ANALYSIS AND FUNCTIONAL ASSESSMENT OF D. ROBLES,
WORLD RECORD HOLDER AND OLYMPIC CHAMPION IN 110 M HURDLES
José Luis López, Josep Maria Padullés and Helena Josefin Olsson
GREAF, University of Vic, Vic, Spain
INEFC, University of Barcelona, Barcelona, Spain
ABSTRACT
A biomechanical analysis of the athlete Dayron Robles’ hurdle race was carried out using state-of-the-art technology, along with the Spanish record holder Jackson Quiñónez. Robles is a world record holder and an Olympic champion in the 110 metre hurdles. Kinematic data is provided, which offers a detailed analysis of Robles’ hurdle race and is related to his performance in strength tests. We reach the conclusion that the high levels of reactive strength, with very short ground contact times, are Robles’ main characteristics in comparison with Quiñónez. In addition, an excessive flight time over the hurdle was noted which his trainer, on being made aware of the results of this research, has managed to correct.
https://ojs.ub.uni-konstanz.de/cpa/article/download/4836/4476
Biomechanical analysis of Colin Jackson’s hurdle clearance technique
By Milan Coh
New Studies in Athletics 18:1; 37-45 2003
ABSTRACT
On the basis of the results obtained by 3 - D kinematic analysis of the 110m hurdles of the World Record holder
Colin Jackson, important parameters defining a model of hurdle clearance technique have been found. Analysis was made of Jackson’s technique over the 4th and 5th hurdles in his race at the Velenje Slovenia 2002 meeting. According to the authoers, efficient hurdle clearance can be defined by the horizontal velocity of the CM during the take-off in front of the hurdle; the height of the CM during the take-off; the velocity of the knee swing of the swinging leg; the flight phase time; the smallest possible loss in the horizontal velocity of the CM during clearing the hurdle; a high position of the CM at landing; a short contact time in the landing phase; and the smallest possible vertical oscillations of the CM, head, shoulders, and hips before, during and after clearing the hurdle. Values for these parameters of Jackson’s technique are given and discussed.
http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCgQFjAA&url=http%3A%2F%2Fwww.richwoodstrack.com%2Frhs_team_area%2Fhurdles%2Ftech_Biomechanical%20Colin%20Jackson%20Form.pdf&ei=XgETVKLbNaeO7Aa3l4GACA&usg=AFQjCNFrjNRdnXvKnQBFuQAG9Gf5KPwNkA&bvm=bv.75097201,d.ZGU
The Most Effective Technical Training For The 110 Metres Hurdles
By Janusz Iskra
New Studies in Athletics 10:3:51-55,1995
Starting from the premise that success in coaching the 110 metres hurdles depends first of all on the athlete’s possession of the requisite physical and motor characteristics, the author describes how experience and the adherence to basic sports principles can make it possible to construct a successful training plan for the individual athlete.
He shows how an analysis of the experiences and methods of successful coaches can be used to select those training exercises which are of universal benefit and how they can best be fitted into the training plan. Ten basic elements of technique training are discussed and copious examples given of exercises and training units by means of which they can be developed.
http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCYQFjAA&url=http%3A%2F%2Fwww.hurdlecentral.com%2FDocs%2FHurdles%2F100%26110_Hurdles%2FIskra_TheMostEffectiveTechnicalTrainingFor110mHurdles.pdf&ei=xFoYVMP7ILLy7Aah2YBY&usg=AFQjCNHvTTrqYtMaVYAvIMyQIpeZdLo_gg&bvm=bv.75097201,d.ZGU
Shock Method and Plyometrics: updates and in-depth examination.
Dr. Yuri Verkhoshansky, has been deemed “The Father of Plyometrics”. Although his main “finding” was that of the shock method, also known as depth jumps. In this presentation, Natalia Verkhoshansky shows the latest contribution and updates of this method, its implications in training the athlete and the taxonomy of Plyometric exercises with the rules of their progressing during the training process.
http://www.verkhoshansky.com/Portals/0/Presentations/Shock%20Method%20Plyometrics.pdf
General Adaptation Syndrome and its applications in Sport Training.
The General Adaptation Syndrome (GAS) has been looked upon as the benchmark for understanding the stress response to training, thus determining the “adaptations” that will be seen in the athletes. On the base of the latest research on GAS, never published in the West, this presentation shows a new and innovative point of view on GAS, areas that coaches can observe, and how this theory has been adapted sense its inception.
http://www.verkhoshansky.com/Portals/0/Presentations/GAS2.pdf
Regional Differences in Muscle Activation During Hamstrings Exercise.
Schoenfeld BJ1, Contreras B, Tiryaki-Sonmez G, Wilson JM, Kolber MJ, Peterson MD.
J Strength Cond Res. 2014 Jun 24
Abstract
It is believed that regional activation within a muscle may lead to greater site-specific muscular adaptations in the activated portion of the muscle. Because the hamstrings are a biarticular muscle, it can be theorized that single-joint exercises where movement originates at the hip versus the knee will result in differential activation of the muscle complex. The purpose of the present study was to assess EMG activity in the proximal and distal aspects of the medial and lateral hamstrings during performance of the stiff- legged deadlift (SLDL), a hip-dominant exercise, and the lying leg curl (LLC), a knee- dominant exercise. Ten young, resistance-trained men were recruited from a university population to participate in the study. Employing a within-subject design, participants performed the SLDL and LLC to muscular failure using a load equating to their 8 repetition maximum for each exercise. The order of performance of exercises was counterbalanced between participants so that approximately half of the subjects performed SLDL first and the other half performed LLC first. Surface electromyography was used to record mean normalized muscle activity of the upper lateral hamstrings, lower lateral hamstrings, upper medial hamstrings, and lower medial hamstrings. Results showed that the LLC elicited significantly greater normalized mean activation of the lower lateral and lower medial hamstrings compared to the SLDL (p < 0.05). These findings support the notion that the hamstrings can be regionally targeted through exercise selection. Further investigations is required to determine whether differences in activation lead to greater muscular adaptations in the muscle complex.
Unfortunately no link to free text however more details about research can be found on the author website.
http://www.lookgreatnaked.com/blog/can-you-target-different-aspects-of-the-hamstrings/
Muscle Activation During Various Hamstring Exercises.
McAllister MJ1, Hammond KG, Schilling BK, Ferreria LC, Reed JP, Weiss LW.
J Strength Cond Res. 2014 Jun;28(6):1573-80
Abstract
The dorsal muscles of the lower torso and extremities have often been denoted the “posterior chain.” These muscles are used to support the thoracic and lumbar spine and peripheral joints, including the hip, knee, and ankle on the dorsal aspect of the body. This study investigated the relative muscle activity of the hamstring group and selected surrounding musculature during the leg curl, good morning, glute-ham raise, and Romanian deadlift (RDL). Twelve healthy, weight-trained men performed duplicate trials of single repetitions at 85% 1-repetition maximum for each lift in random order, during which surface electromyography and joint angle data were obtained. Repeated measures analysis of variance across the 4 exercises was performed to compare the activity from the erector spinae (ES), gluteus medius (GMed), semitendinosus (ST), biceps femoris (BF), and medial gastrocnemius (MGas). Significant differences (p ≤ 0.05) were noted in eccentric muscle activity between exercise for the MGas (p < 0.027), ST (p < 0.001), BF (p < 0.001), and ES (p = 0.032), and in concentric muscle activity, for the ES (p < 0.001), BF (p = 0.010), ST (p = 0.009), MGas (p < 0.001), and the GMed (p = 0.018). Bonferroni post hoc analysis revealed significant pairwise differences during eccentric actions for the BF, ST, and MGas. Post hoc analysis also revealed significant pairwise differences during concentric actions for the ES, BF, ST, MGas, and GMed. Each of these showed effect sizes that are large or greater. The main findings of this investigation are that the ST is substantially more active than the BF among all exercises, and hamstring activity was maximized in the RDL and glute-ham raise. Therefore, athletes and coaches who seek to maximize the involvement of the hamstring musculature should consider focusing on the glute-ham raise and RDL.
Unfortunately no link to free text yet.
Sleep in Elite Athletes and Nutritional Interventions to Enhance Sleep
Shona L. Halson
Sports Medicine, May 2014, Volume 44, Issue 1 Supplement, pp 13-23,
Abstract
Sleep has numerous important physiological and cognitive functions that may be particularly important to elite athletes. Recent evidence, as well as anecdotal information, suggests that athletes may experience a reduced quality and/or quantity of sleep. Sleep deprivation can have significant effects on athletic performance, especially submaximal, prolonged exercise. Compromised sleep may also influence learning, memory, cognition, pain perception, immunity and inflammation. Furthermore, changes in glucose metabolism and neuroendocrine function as a result of chronic, partial sleep deprivation may result in alterations in carbohydrate metabolism, appetite, food intake and protein synthesis. These factors can ultimately have a negative influence on an athlete’s nutritional, metabolic and endocrine status and hence potentially reduce athletic performance. Research has identified a number of neurotransmitters associated with the sleep–wake cycle. These include serotonin, gamma-aminobutyric acid, orexin, melanin-concentrating hormone, cholinergic, galanin, noradrenaline, and histamine. Therefore, nutritional interventions that may act on these neurotransmitters in the brain may also influence sleep. Carbohydrate, tryptophan, valerian, melatonin and other nutritional interventions have been investigated as possible sleep inducers and represent promising potential interventions. In this review, the factors influencing sleep quality and quantity in athletic populations are examined and the potential impact of nutritional interventions is considered. While there is some research investigating the effects of nutritional interventions on sleep, future research may highlight the importance of nutritional and dietary interventions to enhance sleep.
http://link.springer.com/article/10.1007%2Fs40279-014-0147-0
Monitoring Training Load to Understand Fatigue in Athletes
Shona L. Halson
Sports Medicine November 2014, Volume 44, Issue 2 Supplement, pp 139-147,
Abstract
Many athletes, coaches, and support staff are taking an increasingly scientific approach to both designing and monitoring training programs. Appropriate load monitoring can aid in determining whether an athlete is adapting to a training program and in minimizing the risk of developing non-functional overreaching, illness, and/or injury. In order to gain an understanding of the training load and its effect on the athlete, a number of potential markers are available for use. However, very few of these markers have strong scientific evidence supporting their use, and there is yet to be a single, definitive marker described in the literature. Research has investigated a number of external load quantifying and monitoring tools, such as power output measuring devices, time-motion analysis, as well as internal load unit measures, including perception of effort, heart rate, blood lactate, and training impulse. Dissociation between external and internal load units may reveal the state of fatigue of an athlete. Other monitoring tools used by high-performance programs include heart rate recovery, neuromuscular function, biochemical/hormonal/immunological assessments, questionnaires and diaries, psychomotor speed, and sleep quality and quantity. The monitoring approach taken with athletes may depend on whether the athlete is engaging in individual or team sport activity; however, the importance of individualization of load monitoring cannot be over emphasized. Detecting meaningful changes with scientific and statistical approaches can provide confidence and certainty when implementing change. Appropriate monitoring of training load can provide important information to athletes and coaches; however, monitoring systems should be intuitive, provide efficient data analysis and interpretation, and enable efficient reporting of simple, yet scientifically valid, feedback.
http://link.springer.com/article/10.1007/s40279-014-0253-z
Six Sessions of Sprint Interval Training Increases Muscle Oxidative Potential and Cycle Endurance Capacity in Humans.
Kirsten A. Burgomaster , Scott C. Hughes , George J. F. Heigenhauser , Suzanne N. Bradwell , Martin J. Gibala
Journal of Applied Physiology Published 1 June 2005 Vol. 98 no. 6, 1985-1990 DOI: 10.1152/japplphysiol.01095.2004
ABSTRACT
Parra et al. (Acta Physiol. Scand 169: 157–165, 2000) showed that 2 wk of daily sprint interval training (SIT) increased citrate synthase (CS) maximal activity but did not change “anaerobic” work capacity, possibly because of chronic fatigue induced by daily training. The effect of fewer SIT sessions on muscle oxidative potential is unknown, and aside from changes in peak oxygen uptake (V̇o2 peak), no study has examined the effect of SIT on “aerobic” exercise capacity. We tested the hypothesis that six sessions of SIT, performed over 2 wk with 1–2 days rest between sessions to promote recovery, would increase CS maximal activity and endurance capacity during cycling at ∼80% V̇o2 peak. Eight recreationally active subjects [age = 22 ± 1 yr; V̇o2 peak = 45 ± 3 ml·kg−1·min−1 (mean ± SE)] were studied before and 3 days after SIT. Each training session consisted of four to seven “all-out” 30-s Wingate tests with 4 min of recovery. After SIT, CS maximal activity increased by 38% (5.5 ± 1.0 vs. 4.0 ± 0.7 mmol·kg protein−1·h−1) and resting muscle glycogen content increased by 26% (614 ± 39 vs. 489 ± 57 mmol/kg dry wt) (both P < 0.05). Most strikingly, cycle endurance capacity increased by 100% after SIT (51 ± 11 vs. 26 ± 5 min; P < 0.05), despite no change in V̇o2 peak. The coefficient of variation for the cycle test was 12.0%, and a control group (n = 8) showed no change in performance when tested ∼2 wk apart without SIT. We conclude that short sprint interval training (∼15 min of intense exercise over 2 wk) increased muscle oxidative potential and doubled endurance capacity during intense aerobic cycling in recreationally active individuals.
http://jap.physiology.org/content/98/6/1985
Yeah, this was a very interesting article.
Thanks for posting it.