This doctoral thesis deals with the kinesiological analysis of the athletic run - sprint. The aim of the thesis is the time characteristics comparison and switching on of the muscles which are working during the sprint before and after the performance of special running exercises. It is becoming much more important to use the special training procedures during training sessions. The special running exercises are performed almost daily during training sessions of sprinters. The question is to what extent their performance is evident on the activation of muscles. The qualitative and quantitative results show the activation of muscles during sprint before and after the performance of the special running exercises. The main tool of the research was the surface EMG analysis of muscles during a 30-metre long sprint. The content of the research were two comparative analysis, where 8 proband participated - interindividual and intraindividual. During the evaluation process we considered the quantitative and qualitative components. On the basic of the reached results we may say that there is no diference between the run before and after the performance of special running exercises. Keywords: Sprint, special running exercises, electromyography, ANOVA

The purpose of this study was to identify a potentiation effect on 30 meter (m) fly sprint performance in collegiate sprinters and jumpers (M=21, W=5) following an acute bout of whole-body vibration. The WBV protocol consisted of one 30 second bout at 50 Hz, ~3 mm amplitude, and 60 seconds rest before a 30m fly sprint. Sprint times were measured using timing gates, and characteristics of strength and power were measured using a force plate. Analysis included measures of jump height, peak power, peak force, and rate of force development. Each subject participated in 3 separate trials using randomized treatment sessions over 3 months of preparation training. The control condition consisted of no vibration and WBV treatment 1 and 2 incorporated vibration. Statistics comparing the average sprint times showed no treatment effects. The results of this study indicate that WBV at 50 Hz and ~3 mm amplitude has no effect on sprint times.

In the sport of track and field, sprinting and distance running represent two major categories of athletes. Sprinting is associated with power and speed, whereas distance running focuses on the economy of movement. With distance running there are elements of sprint technique that overlap. With distance events, there comes a time near the end of the race where economy gives way to speed. If the distance runners knew how to alter their technique in a way to become more sprint-like, this process could possibly be more successful. PURPOSE: This study compared the differences in technique between sprinters and distance runners while running at equal and maximal speeds. METHODS: Subjects for the study consisted of 10 Division I collegiate distance runners, 10 Division I collegiate sprinters, and 10 healthy non-runners. The subjects performed two tests, with each consisting of a 60 meter run completed on the track. Test 1 was run at a pace of 5.81 m/s (4:37 min/mile), while Test 2 was completed at maximal speed. Video footage of each trial was collected at 180 Hz, monitoring hip, knee, thigh, and shank positions, as well as stride length, and contact time. RESULTS: Significant differences (p < .05) between the sprint and distance groups at maximal speed were found in the following areas: speed, minimum hip angle, knee extension at toe-off, stride length, contact time, and the position of the recovery knee at touchdown. Sprinters and distance runners exhibited a significantly lower minimum knee angle than those in the control group. Significant differences between the sprint and control group existed at the minimum hip angle, speed, stride length, contact time, and the position of the recovery knee at touchdown. Regarding the paced trial, the sprinters and distance runners showed significant difference concerning the minimum hip angle, center of mass at touchdown, and recovery knee at touchdown. Sprinters differed significantly from the control group in contact time, the center of mass at touchdown and the position of the recovery knee at touchdown. CONCLUSION: As distance runners attempt to sprint, the desired adaptations do not necessarily occur. The development of economical distance form is a fairly natural process that occurs with the miles of training. Sprinting, however, is a separate, learned technique that often requires specific feedback. When attempting maximal speed, distance runners may benefit by focusing on one characteristic of technique. If knee extension at toe-off could be trained to become more sprint-like, the other characteristics unique to sprinters may follow.

The critical power (CP) concept has been used to determine the appropriate rest interval during intermittent exercise through the investigation of critical rest interval (CRI). Repeated sprint ability (RSA) testing has been developed to define the athlete’s ability to recover and maintain maximal effort during successive bouts. The CP model has been used to understand the physiological responses involved with intermittent exercise delineating between severe and heavy exercise intensity domains. The primary purpose of this study was to determine the CRI from the work-time relationship given by RSA testing using varying work to rest ratios. The secondary purpose was to determine the validity of CRI by evaluation of physiological responses above and below estimated rest interval values during intermittent cycling. Twelve recreationally trained males (mean ± SD; age 24.1 ± 3.6yr; height 175.8 ± 7.0cm; weight 77.6 ± 12.8kg; V̇ O2peak 43.3 ± 5.6ml/kg/min; Body Fat (%) 24.5 ± 4.4) were recruited for this study. Participants performed a graded exercise test to determine V̇ O2peak and peak heart rate. Eight participants completed the same three RSA protocols with 6s maximal sprints and varying rest intervals (12-24s) on a cycle ergometer. Intermittent critical power (ICP) was calculated through the linear total work (TW) and time-to-exhaustion (TTE) relationship, whereas CRI was estimated using the average work per sprint and ICP. Seven subjects completed trials above and below estimated CRI to evaluate the validity of this estimate through the examination of the physiological responses. Breath-by-breath oxygen consumption (V̇ O2) and heart rate (HR) values were recorded during the validation trials. One-way repeated measures analysis of variance (ANOVA) was used to analyze the variables from the RSA trials. Paired samples t-tests were performed to compare performance and physiological variables above or below CRI during the validation trials. Two-way repeated measures ANOVA was used to examined the changes in oxygen consumption (V̇ O2), HR, mean power (MP), and TW throughout the validation trials. Significant differences (p < 0.1) were found for the number of intervals completed, TTE, average work per sprint, peak and mean V̇ O2 between RSA protocols. Linearity between TW and TTE was r2 = 0.952 ± 0.081. During the validation trials, TTE was significantly greater in the above versus the below CRI trial (2270.43 ± 941.15s vs. 1511.00 ± 811.0s). Furthermore, blood lactate concentration (8.94 ± 4.89mmol/L vs. 6.56 ± 3.45mmol/L), AveV̇ O2 (2.05 ± 0.36L/min vs. 1.78 ± 0.26L/min), V̇ O2peak (2.84 ± 0.48L/min vs. 2.61 ± 0.43L/min), and AveHR (151.14 ± 18.46bpm vs. 138.14 ± 17.51L/min) were significantly greater in the below CRI trial when compared to the above CRI trial. Significant interactions were found between above and below trials within minimal V̇ O2 response (F = 6.886, p = 0.024, η2 = 0.534) to the recovery intervals and maximal HR (F = 4.51, p = 0.016, η2 = 0.429) response to the work intervals. During the above CRI trial, minimal V̇ O2 response decreased over time (51-43%V̇ O2 peak) while maximal HR response achieved a steady state level (81-84%HRpeak). Conversely, minimal V̇ O2 response during the below CRI trial achieved a steady state level (54-58%V̇ O2 peak), whereas maximal HR response increased over time (84-90%HRpeak). The relationship between TW and TTE is appropriate for use with RSA testing with varying rest intervals. The differing physiological response during the validation trials may reflect changes in energy system contribution. In conclusion, CRI distinguished between physiological responses related to exercise intensity domains in a manner similar to CP estimates determined from other testing and exercise modalities.

One very common axiom amongst Strength and Conditioning Professionals and Athletic Performance Coaches is that the least flexible athletes usually produce the fastest 40-yard dash times. Flexibility, in this case specifically refers to posterior chain flexibility (PCF). This is usually measured by athletes ability to perform a sit-and-reach test. This train of thought has been widely accepted within the human performance professions, even though it is void of any scientific investigation or measured validity. The purpose of this study is to determine if there is a relationship between posterior chain flexibility using the sit-and-reach test and speed in the 40-yard dash. All test subjects were male between the ages of 18-22, and members of a Division I university football team. All 95 test subjects had participated in at least one semester of a strength and conditioning program designed by Certified Strength and Conditioning Specialists. Similar of the study done by Johnson (2001), each athlete was placed in a group based on position, line of scrimmage groups (LOS), Skill group (receivers, cornerbacks, rover linebackers, whip linebackers, and safeties), Combo group (inside linebackers, tight ends, quarterbacks, tailbacks, fullbacks, and defensive ends), Specialist group (place- kickers, kick-off specialists, holders, and punters). Each test subject was tested in the 40-yard dash, the sit-and-reach flexibility test, as well as other tests for strength and power such as the bench press, front squat, push jerk, power clean, vertical jump, and agility tests. Body weight and height was also measured. This study used a simple linear regression on the data where the Sit-and-Reach test results were the dependent variable and the subjects timed results in a 40 yard dash was the independent variable. There appears to be no significant relationship between a low flexibility score and the sprint speed of an athlete for the entire group population. The results also show that there is no significant relationship between flexibility of the posterior chain and linear speed as measured in the 40-yard dash when looking at football players that fall under the Combo, Skill, or LOS position groups. There was however a significant relationship for the specialist group. The theory that the least flexible athletes usually produce the fastest 40-yard dash times is not true for those specific groups. / Ph. D.

No description available.

<p> Increased arterial stiffness and vascular endothelial dysfunction have been identified as independent risk factors for the development and progression of cardiovascular disease. Traditional endurance training has been associated with elevated levels of central arterial compliance and an attenuation of cardiovascular events. As well, the positive benefits of aerobic-based training have been acknowledged as effective modulators of vascular endothelial function. To date, the impact of sprint interval training on cardiovascular health has not been evaluated. Furthermore, the mechanisms responsible for previously observed enhancements in endurance (750 kJ) performance following two weeks of sprint interval training remain unclear, but may be related to changes in vascular structure and function.</p> <p> Nine young healthy males [age: 22 ± 0.5 (mean± SEM)] participated in a two week sprint interval training program consisting of 4-6 30 second maximum effort exercise bouts performed every other day on a cycle ergometer. In addition, each participant was required to complete a 750 kJ time trial on a cycle ergometer as a measure of aerobic exercise performance before (PRE) and after (POST) training. Measurements of supine, resting carotid pulse pressure, carotid cross-sectional compliance, and brachial vascular endothelial function (using flow mediated dilation) were also acquired PRE and POST training.</p> <p> Resting pulse pressure did not show any significant changes with exercise training (PRE= 48.6±1.6, POST= 52.4±2.5 mmHg, p>0.05). Mean brachial artery diameter was not changed with sprint interval training (PRE= 4.29±0.17, POST= 4.38±0.18 mm, p>0.05); however, mean carotid artery diameter increased significantly PRE to POST (PRE= 6.40±0.15, POST= 6.49±0.14 mm, p=0.008). Carotid cross-sectional compliance did not change PRE to POST training (PRE= 0.164±0.010, POST= 0.162±0.007 mm^2/mmHg, p>0.05). Brachial vascular endothelial function measured using flow-mediated dilation did not show a significant change with sprint interval training, however a trend towards improvement was noted (PRE= 4.6±1.8, POST= 6.4±1.0 %, p=0.296). When normalized for shear rate (which was also unaltered with sprint interval training) there were no changes in endothelial function (PRE = 0.158±0.068, POST= 0.198 ± 0.034 %/S^-1, p>0.05). Average brachial post-occlusion blood flow was significantly enhanced following training possibly revealing enhanced resistance vessel function (PRE= 296.0±37.4, POST= 324.8±38.8 ml/min, p=0.04), despite no change in peak brachial blood flow (PRE= 332.0±42.3, POST= 362.6±45.7 ml/min, p>0.05). 750 kJ time trial performance was significantly enhanced with training (PRE = 62.8±4.9; POST= 55.84±3.55 min; p=0.006).</p> <p> In conclusion, sprint interval training did not change resting carotid compliance or brachial endothelial function, despite significant improvements in aerobic performance (750 kJ). However, carotid resting diameters and brachial post occlusion blood flow were significantly increased PRE to POST and a trend towards improvement was seen for brachial flow mediated dilation. The exact mechanisms responsible for such changes remain unknown and require further investigation.</p> / Thesis / Master of Science (MSc)

During inpatient rehabilitation, arm-ergometry training is utilized to improve the physical capacity of patients with a sub-acute spinal cord injury (SCI) to a level that is desirable for performing activities of daily living (ADLs). Previous work has demonstrated that ≥ 20 minutes of moderate-intensity continuous training (MICT) during inpatient rehabilitation, at a frequency of ≥ 3 times per week, is useful for increasing the physical capacity of these patients. However, considering that inpatient rehabilitation is an intensive program, and given the trend towards a shortened length of stay during inpatient rehabilitation, performing MICT on the arm-ergometer can consume a valuable amount of therapy time. Low-volume sprint interval training (SIT) is a time-efficient alternative to MICT for improving indices of physical fitness in healthy and diseased populations. To date, however, there are no published studies comparing SIT to MICT in persons with sub-acute SCI undergoing inpatient rehabilitation.The purpose of this thesis was to evaluate the efficacy of a five-week, thrice weekly low-volume SIT protocol on the arm-ergometer and compare fitness outcomes to traditional MICT in patients with sub-acute SCI undergoing inpatient rehabilitation. Participants with sub-acute SCI undergoing inpatient rehabilitation were recruited and randomly allocated to the SIT or MICT training group. Both types of training utilized the same 2 min. warm-up and 3 min. cool-down. SIT consisted of 3 x 20 sec. “all-out” cycle sprints (≥ 100% of peak power output [POpeak]), interspersed with 2 min. of low activerecovery (≈ 10% of POpeak; total time commitment, 10 mins). MICT involved 20 min. of arm cycling (45 – 60% of POpeak; total time commitment, 25 mins). SIT elicited a higher relativheart rate response, and ratings of perceived exertion than MICT. Following training, we found similar improvements in maximal and sub-maximal physical capacity across groups. Both exercise modes were equally well tolerated, and enjoyable, and there were no differences in self-efficacy across groups. The significance of this work is that it is the first randomized-controlled trial comparing SIT to MICT on the arm-ergometer in individuals with sub-acute SCI undergoing inpatient rehabilitation. The fact that SIT is palatable and can promote similar increases in physical capacity as MICT, despite less than half the time commitment and training volume, means that clinical rehabilitation specialists can now offer a new, more time-efficient, exercise training strategy to elicit improvements in their patients. / Thesis / Master of Science (MSc)

A fully instrumented on-water sprint canoe system was designed, built, and tested. The system consists of: one 6-axis load cell in the paddle shaft at the blade, one inertial measuring unit (IMU) on the paddle, one IMU on the boat, and one GPS unit on the canoe boat. These sensors communicated wirelessly to a laptop where the data was processed and displayed in real-time. The sensors were rigorously tested and well-measured in their satisfactory accuracy. The system can provide a full decomposition of the blade water force into propulsive (forward/aft), side, and vertical forces. Previous systems for canoe have been extremely simple and rudimentary. There has been more effort in the rowing and kayak systems but they still failed to capture a full force profile. On-water tests with national-level athletes examined a wide variety of sprint canoe strokes at different paces, power inputs, rates, and stroke lengths. The measurement system could clearly see the differences in force profiles between the stroke sets. A number of efficiency measures were developed using the available data. Instantaneous and integral in-stroke force ratios were developed based on the blade's propulsive force to total force proportion. Derived stroke averaged efficiencies also provided more information. These produced measurements of energy/impulse input to the boat's propulsion output. Differences in such efficiencies could be clearly seen in the various collected stroke sets. This system will be highly useful to high performance athletes and coaches for modifying athlete technique. It has potential for improving equipment design and matching athletes to optimal blade styles. More academically, it can assist biomechanical assessments of sprint canoe and numerical flow studies around blades. / Thesis / Master of Applied Science (MASc) / A measurement system for a sprint canoe paddle was created that can evaluate an athlete's stroke performance during race-like conditions. This system was tested using national-level athletes in a true on-water setting. By measuring the force and orientation of the athlete's strokes, the system was able to clearly distinguish the performance of various stroke techniques. Analysis of the force profiles and the derivation of stroke efficiencies provided additional performance indicators. This is the first system to achieve this amount of measurement detail of any rowing or paddling sport. This fully instrumented paddle system is ready to be used as a coaching tool to improve athlete performance. It can also be used as an academic tool for paddle blade study.

Dans la recherche de nouvelles alternatives pour optimiser les adaptations à l'entraînement et la performance, le pré-conditionnement ischémique (ischemic preconditioning, IPC, en anglais) a récemment attiré beaucoup d'attention en ce qui touche l'optimisation de méthodes d'entraînement éprouvées. L'ajout de cette manœuvre avant l'effort permettrait donc de créer de plus grandes adaptations au niveau physiologique et d'augmenter la performance. La manœuvre consiste à alterner des cycles de compression et de reperfusion avec des brassards de pression, de façon à limiter l'apport en sang et en oxygène aux membres ciblés. Il a été démontré que l'IPC permet d'améliorer les puissances maximale et moyenne, ainsi que la force maximale concentrique, qui sont des composantes clés de la performance en sprint. Cependant, peu de chercheurs se sont intéressés aux effets chroniques de l'IPC sur la performance en sprint. De plus, il existe très peu d'études qui documentent les effets physiologiques de l'IPC sur la fonction neuromusculaire ainsi que les effets de l'utilisation conjointe de cette technique avant des entraînements en sprint. L'étude présentée dans ce mémoire avait pour objectif primaire de mieux comprendre les effets chroniques de l'IPC sur la performance en sprint, et pour objectif secondaire de vérifier ses effets sur l'activité neuromusculaire. Les résultats rapportés dans ce mémoire mettent en évidence une augmentation de la puissance moyenne lors des 10 dernières secondes d'un test de Wingate de 30 sec, ainsi qu'une diminution de l'indice de fatigue lors de ce même test à la suite de 4 semaines d'entraînement en sprint combiné à l'IPC. Parallèlement à ce gain de performance, nos résultats montrent un meilleur maintien de la fréquence de stimulation de la commande motrice. Il semble donc que l'application chronique d'IPC avant des entraînements de sprint permet d'optimiser les effets d'un protocole d'entraînement en sprint, résultant en une meilleure tolérance à la fatigue lors d'un test de Wingate. / As athletes advance in competitive level, improvements in performance become smaller and harder to produce. In the continuous search for new and better ways to optimize training adaptations and performance, ischemic preconditioning (IPC) has attracted recent interest in enhancing otherwise proven training methods. The addition of such a maneuver prior to an effort could promote physiological adaptations which could enhance performance. Ischemic preconditioning can improve peak and mean power output, as well as maximal concentric strength, which are key components of sprint performance. This maneuver consists of alternating cycles of compression and reperfusion using blood pressure cuffs to limit blood and oxygen supply to the targeted limbs and muscles. To date, few researchers have investigated the chronic effects of IPC on sprint performance, and little research currently documents the physiological effects of IPC on the neuromuscular function. Furthermore, limited studies have looked at the combination of IPC and sprint training. The article presented in this thesis aimed at better understanding the chronic effects of sprint training preceded by IPC on neuromuscular activity and sprint performance. The results of this thesis highlight an increase in mean power output in the last 10 seconds of a Wingate test, as well as a decrease in the fatigue index following 4 weeks of sprint training combined with IPC. Concomitantly to these performance gains, we observed a better maintenance of the mean power frequency of the electromyogram. We concluded that applying IPC before sprint training alters the stimulation pattern of muscle fibers and enhances fatigue resistance during a Wingate sprint. Coaches could use such training stimulus in order to enhance neuromuscular adaptations.