Fatigue induces changes to running form; therefore movement is not as effective or efficient. Reducing the amount of fatigue or its effects on form would be ideal to improve performance while running. Compressive clothing has unknown effects on musculature, however it claims to reduce fatigue. The aim of this study was to see the changes in running form while running to exhaustion and to see how compression tights can effect these changes. Eleven runners ran at their current five-kilometer race pace on a treadmill to voluntary exhaustion in a repeated measures design wearing compression tights and regular shorts while their kinematics, kinetics, heart rate and rate of perceived exhaustion were recorded. There was not a significant difference in time to exhaustion. Fatigue general effects were significant from beginning to end in knee and ankle angle at initial contact with the knee becoming less extended and the ankle less dorsiflexed. Vertical ground reaction loading rate and impact peak were significantly different from beginning to mid point and beginning to end across conditions. Heart rate and rate of perceived exertion increased significantly with fatigue as well in both conditions. Condition effects were significant in stride length and rate with a decreased stride length with compression tights and an increased stride rate with compression tights. The hip experienced a decreased range of motion in the compression tights compared to running shorts. These results indicate that there are effects of fatigue on performance and differences between conditions. These differences did not affect the overall outcome of run as measured in time to exhaustion. / School of Physical Education, Sport, and Exercise Science

The purpose of this study is to determine physiological adaptations in trained male high-school runners before and after high-intensity training associated with a crosscountry season. Testing occurred on five separate occasions at the Human Performance Laboratory. After the first familiarization session, the subjects performed a treadmill graded exercise test in which maximal oxygen consumption and ventilatory threshold was measured. Submaximal oxygen consumption and blood lactate concentration at three running speeds (10, 12, and 14 km'hf 1 at 0% grade) was determined in a second testing session. After the cross-country season (13 weeks) the subjects returned to the laboratory and performed the same graded exercise and submaximal exercise tests. VO2max significantly increased, VT tended to increased, however, not significant. There were no changes in submaximal economy or lactate except for significant decline in blood lactate at 14 km hf' . Although these variables are associated with endurance performance in adults, there is very little information available regarding the effects of endurance training on these variables in the adolescent age group. Knowing the extent of the adaptations will help to optimize the training programs for age group. / School of Physical Education

This study evaluated the training adaptations in female adolescent cross-country runners over two training seasons. Although the effects of endurance training in this population are understood, the specific adaptations resulting from pre-season and in-season training are not clear. The physiological changes occurring over these two training seasons in 10 female runners (15.7 ± 0.8 yrs, 165.6 ± 5.6 cm, 53.8 ± 6.1 kg) were assessed. Maximal exercise responses were measured during a continuous graded exercise test and submaximal exercise responses were quantified at 7 and 8 mph. Isokinetic muscle strength was assessed at four movement speeds (60-240°/sec) and muscle power was calculated using vertical jump height. Body composition also was assessed. HR at maximal and submaximal exercise declined during pre-season training and then increased during in-season training. Blood lactate [BLa] measurements at 7 and 8 mph decreased following summer training. Whole body bone mineral content (BMC) and bone mineral density, and femoral head BMC increased. In conclusion, it appears that high volume, low intensity training lowers [BLa] with no corresponding change in oxygen utilization in highly trained female adolescents. Running also appears to have a positive impact on bone mass in female adolescents. / School of Physical Education, Sport, and Exercise Science

The purpose of this study was to compare the anabolic response to acute running exercise in two different leg muscles in endurance-trained men using two different stable isotope tracers. 6 male subjects (26±2 yr; V02max 63±2 ml•kg-' •min-') performed a 45 min treadmill run at 77±1 % intensity. Infusions of d3-leucine and d5-phenylalanine were used to measure mixed muscle FSR at rest and 24 hr post-exercise. An additional infusion of 10% amino acid solution was added to the post-exercise infusion to maximize the muscle anabolic response. Muscle biopsies were obtained from the vastus lateralis (VL) and soleus (SOL) at 2 and 6 hr of the infusion for the measurement of isotope incorporation. Additional muscle biopsies were obtained prior to and 4 hr post-exercise for determination of muscle glycogen use. At rest FSR was similar between the VL and SOL using either tracer (p>0.05). At 24 hr post-exercise FSR was elevated in both muscles, independent of the tracer used (p<0.05). Muscle glycogen was decreased to the same extent in both muscles by -31% at 4 hr post-exercise (p<0.05). These data suggest that the VL and SOL muscles are both stimulated similarly during 45 min of level grade running. Additionally, both muscles respond similarly 24 hr post-exercise, independent of the tracer used for the determination of protein synthesis. / School of Physical Education, Sport, and Exercise Science

Background: The most common injuries in new or novice runners include medial tibial stress syndrome and patellofemoral pain syndrome; both overuse injuries. It is known that novice runners use a rearfoot strike pattern 98% of the time while running in traditional running footwear. Furthermore, footwear that is constructed with less cushioning (minimal shoes) and is said to promote forefoot running has increased in popularity. It is still unknown if novice runners convert their strike pattern in minimal shoes or continue to use a rearfoot strike pattern. Consequences of continuing to use a rearfoot strike pattern with less cushioning underfoot include higher vertical loading rates which are directly related to the types of injuries experienced. Aside from the strike pattern in a given shoe, movement stability is an important feature in healthy locomotion. There is a trade-off between being overly stable and being too unstable while running. It is known that the level of experience in running is related to the amount of stride length variability. It is still unknown if altering midsole stiffness has an effect on local dynamic stability while running. Purpose: The primary purpose of this thesis was to compare landing kinematics and kinetics between trained and novice runners in minimal and traditional shoes. The secondary purpose of this thesis was to examine the effect of running experience and midsole construction on local dynamic stability at the ankle, knee and hip. Methods: Twelve trained runners and twelve novice runners were recruited for participation. Four prototypical shoe conditions were tested with midsole geometry and material stiffness being manipulated. This yielded traditional/soft, traditional/hard, minimal/soft and minimal/hard shoe conditions. Participants ran down a 30m indoor runway which was instrumented with force platforms to measure vertical loading rates and motion capture cameras to capture landing kinematics. Participants also ran on a treadmill in each shoe condition to allow for local dynamic stability to be estimated at the ankle, knee and hip in the sagittal plane. Results: Novice runners landed with increased knee extension compared to trained runners. Increasing midsole thickness of the shoes caused an increase in dorsi-flexion of the ankle at heel strike. Manipulating material stiffness did not influence landing kinematics but did influence kinetics. Furthermore, decreasing material stiffness lowered vertical loading rates. Trained runners exhibited increased local dynamic stability (more stable) at the ankle, knee and hip compared to novice runners. Local dynamic stability was not affected by midsole stiffness. Conclusions: Novice runners did not alter their strike pattern in minimally constructed shoes. For this reason, cushioning properties of the shoe dictated vertical loading rates upon the body. Shoe conditions did not alter landing kinematics above the ankle, which is where the between group differences existed as novice runners landed with a more extended knee. Running experience appears to play a role in knee orientation at landing and is unaffected by shoe condition. Local dynamic stability was affected by running experience and does not appear to be related to the shoe condition being worn. Even when kinematics changed across shoe conditions, the stability of the movement did not.

Past research on the acceleration phase in sprint running has concentrated on the kinematics of sprint blocks set-up and the initial steps after exiting the sprint blocks. In contrast, there has been limited research on the ground reaction forces (GRF) generated during the initial post-block foot contacts. These initial foot contacts in sprinting are important for optimising performance in the initial acceleration phase of sprinting. However, little is known about the GRF elite sprinters generate during the initial foot contacts and how these GRF characteristics relate to performance. It is the anterior-posterior (A-P) GRF that are of most importance as they indicate the sprinter’s motion from the start to the finish line. This thesis investigates the A-P GRF of the first two foot contacts of the sprint start after leaving the blocks. The participants included seventeen male and six female sprinters with a mean age of 22.6 (SD 4.4 years). Seventeen of the sprinters had competed at international/national level competitions and six at recreational/amateur level competitions. The athletes were classified as senior male elite (SME), senior female elite (SFE), junior male elite (JME) and senior male recreational (SMR). The sprinters were instructed to perform block starts at maximal effort to produce the fastest time over 5 metres on a 30 metre indoor laboratory track. Timing gates were used to record 5 metre times and two strain gauge force plates were placed in series to collect GRF data from the first two foot contacts after leaving the starting blocks. From the GRF data, braking time, maximum A-P braking force, A-P braking impulse, propulsive time, maximum A-P propulsive force, A-P propulsive impulse and A-P contact impulse were determined for each trial. The A-P propulsive phase constituted greater than 90% of the total contact time, had approximately twice the magnitude of the maximum force of the braking phase and accounted for more than 95% of the total contact impulse across the four groups of sprinters. The SME group produced a significantly larger A-P propulsive impulse on the first and second steps compared to the SFE (p less than 0.05 and p less than 0.05 respectively), JME (not significant and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s maximum A-P propulsive force was significantly larger on the first and second steps than the SFE (p less than 0.05 and p less than 0.05 respectively), JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s propulsive time on the first and second steps was not significantly different compared to the SFE (both not significant) but was significantly shorter compared to the JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The maximum A-P propulsive force correlated strongly with 5 metre time for the first step (rs = -0.670, p less than 0.01), second step (rs = -0.621, p less than 0.01) and the addition of the first and second steps (rs = -0.678, p less than 0.01) across all the sprinters. Whereas, the A-P propulsive impulse correlated strongly with 5 metre time for the first step (rs = -0.525, p less than 0.01), second step (rs = -0.592, p less than 0.01) and the addition of the first and second steps (rs = -0.584, p less than 0.01). Three A-P GRF patterns were observed during the first and second foot contacts of the sprinters examined in this study. A braking-propulsive (B-P) pattern was the most frequently observed followed by a propulsive-braking-propulsive (P-B-P) and a no braking (NB) pattern 82.7%, 15.4% and 1.9% respectively. The P-B-P and NB patterns, which have not been described previously, appeared most frequently in the least experienced sprinters. In the past, some sprinters and their coaches have tried to minimise the braking phase and maximise the propulsive phase of the first two foot contacts after exiting the blocks during sprinting. This study suggests that increasing the maximum propulsive force is the best way to increase performance over the first 5 metres of the acceleration phase. The research also suggests that there will be little benefit gained from trying to increase performance by focusing on the braking phase during these first two steps after exiting the blocks. As such, sprinters and coaches should focus their attention primarily on producing a large A-P propulsive force during the first two steps of a sprint.

Past research on the acceleration phase in sprint running has concentrated on the kinematics of sprint blocks set-up and the initial steps after exiting the sprint blocks. In contrast, there has been limited research on the ground reaction forces (GRF) generated during the initial post-block foot contacts. These initial foot contacts in sprinting are important for optimising performance in the initial acceleration phase of sprinting. However, little is known about the GRF elite sprinters generate during the initial foot contacts and how these GRF characteristics relate to performance. It is the anterior-posterior (A-P) GRF that are of most importance as they indicate the sprinter’s motion from the start to the finish line. This thesis investigates the A-P GRF of the first two foot contacts of the sprint start after leaving the blocks. The participants included seventeen male and six female sprinters with a mean age of 22.6 (SD 4.4 years). Seventeen of the sprinters had competed at international/national level competitions and six at recreational/amateur level competitions. The athletes were classified as senior male elite (SME), senior female elite (SFE), junior male elite (JME) and senior male recreational (SMR). The sprinters were instructed to perform block starts at maximal effort to produce the fastest time over 5 metres on a 30 metre indoor laboratory track. Timing gates were used to record 5 metre times and two strain gauge force plates were placed in series to collect GRF data from the first two foot contacts after leaving the starting blocks. From the GRF data, braking time, maximum A-P braking force, A-P braking impulse, propulsive time, maximum A-P propulsive force, A-P propulsive impulse and A-P contact impulse were determined for each trial. The A-P propulsive phase constituted greater than 90% of the total contact time, had approximately twice the magnitude of the maximum force of the braking phase and accounted for more than 95% of the total contact impulse across the four groups of sprinters. The SME group produced a significantly larger A-P propulsive impulse on the first and second steps compared to the SFE (p less than 0.05 and p less than 0.05 respectively), JME (not significant and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s maximum A-P propulsive force was significantly larger on the first and second steps than the SFE (p less than 0.05 and p less than 0.05 respectively), JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s propulsive time on the first and second steps was not significantly different compared to the SFE (both not significant) but was significantly shorter compared to the JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The maximum A-P propulsive force correlated strongly with 5 metre time for the first step (rs = -0.670, p less than 0.01), second step (rs = -0.621, p less than 0.01) and the addition of the first and second steps (rs = -0.678, p less than 0.01) across all the sprinters. Whereas, the A-P propulsive impulse correlated strongly with 5 metre time for the first step (rs = -0.525, p less than 0.01), second step (rs = -0.592, p less than 0.01) and the addition of the first and second steps (rs = -0.584, p less than 0.01). Three A-P GRF patterns were observed during the first and second foot contacts of the sprinters examined in this study. A braking-propulsive (B-P) pattern was the most frequently observed followed by a propulsive-braking-propulsive (P-B-P) and a no braking (NB) pattern 82.7%, 15.4% and 1.9% respectively. The P-B-P and NB patterns, which have not been described previously, appeared most frequently in the least experienced sprinters. In the past, some sprinters and their coaches have tried to minimise the braking phase and maximise the propulsive phase of the first two foot contacts after exiting the blocks during sprinting. This study suggests that increasing the maximum propulsive force is the best way to increase performance over the first 5 metres of the acceleration phase. The research also suggests that there will be little benefit gained from trying to increase performance by focusing on the braking phase during these first two steps after exiting the blocks. As such, sprinters and coaches should focus their attention primarily on producing a large A-P propulsive force during the first two steps of a sprint.

Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2007. / Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 6 uppsatser.