M.Phil. (Sport & Movement Studies) / Resistance training (RT) is an essential element of fitness for most sports. Most athletic activities involve faster and more powerful movements than those found in maximal strength exercises. Thus athletes could be exceptionally strong but lack explosive power. The aim of the study was to determine the possible effect of two different RT programmes on the sprinting performance of men aged 18–25. Body composition was assessed via anthropometrical measurements and lower extremity power was assessed via vertical jump and the Margaria Kalamen Power Test. Speed and acceleration will be assessed via a 40 meter, 60 meter, 80 meter and 100 meter sprint tests. Thirty athletes were randomly divided into three groups (two experimental groups n=10 each and a control group n=10). Two different RT programmes (“General”, G and “Specialised”, SP) were applied for eight weeks in the two experimental groups, while the control group (C) had no form of strength training. Both training programmes included two sessions per week, each lasting 60 minutes. Components that were tested included anthropometrical, body composition, lower extremity strength and 1RM measurements in regards to their 40m, 60m, 80m and 100m sprint time. Significant difference between SP, GP and C, at a P-value of 0.05, was determined by a dependant t-test. An independent t-test was used to determine significant difference between the three groups. The results showed that there was a significant improvement on body fat (BF) % in SP (-1.71 ± 0.21), GP (-0.19 ± 0.57) and muscle mass (MM) % in SP (1.88 ± 3.23). There was a significant difference in explosive power (MK) for the specialised group (p=0.013) and the 60m sprint for the specialised group (p=0.047). One repetition maximum (1RM) bench press (p=0.005 SP and GP), 1RM deadlift (p=0.005 SP), 1RM power clean (p=0.005 SP) and 1RM squat (p=0.005 GP) improved in the relevant groups as indicated. There was a significant difference between the groups completing a 60m sprint (p=0.022), 80m sprint (p=0.057), 100m sprint (p=0.025) and 1RM bench strength test (p=0.007) at post-test. Positive correlations were found between MM% on 60m (p=0.021), 80m (p=0.01) and 100m (p=0.019) sprinting times and MK and 40m (p=0.015) sprinting time.

This investigation used a constant-load cycle ergometer as a way of examining relationships between the cycle ergometer and sprint performance. Twenty-five college-aged males were used for this investigation. Following a three minute warm-up, each subject performed a 15 sec. maximal bout on the cycle ergometer. The resistance load on the ergometer was set at 0.12kg/kg of bodyweight. Peak power (PP), average power (AP), time to peak power (TTPP), power fatigue rate (PFR), and power fatigue index (PFI) were computed using a microcomputer system. In addition, PP,AP, and PFR were adjusted for total bodyweight (PP/kg, AP/kg, PFR/kg). On a separate day each subject performed six sprints two each at 50m, 100m, and 200m. Each sprint was electronically timed using an infra-red motion detector and starting blocks were used. Initially low correlations were found between the ergometer parameters and the sprint times (r=.07-.55). However upon closer evaluation stronger relationships appeared to exist for the faster subjects. Therefore, subject subgroups of faster subjects were formed. Subject subgroups for the 5 Om (T<7.5sec.), 100m (T<l4sec.)}, and 200m (T<26.6sec.) showed higher correlations (r=.06-.70). Further analysis revealed that high inter-variable correlations existed between many of the ergometer variables. Based on these correlations the parameters were separated into four groups. Group I contained variables of absolute power (PP,AP), group II were variables of relative power (PP/kg, AP/kg), group III contained variables of fatigue (PFR, PFI, PFR/kg), and group IV consisted of the acceleration variable (TTPP). Equations for predicting sprint performance were developed using one to four variables with only one variable from each group being used. The best equation was considered to be the one that yielded the highest r* value while also yielding the lowest Akakai Information Criteria value and MSE. Variables from the relative power group (PP/kg, AP/kg) and fatigue group (PFR, PFI, PFR/kg) were the best indicators of performance. These results suggest that the cycle ergometer used in this investigation can be used for evaluating the components of sprint performance in untrained males, and that this test is best when compared to the 200 m dash. / Master of Science

Thesis (PhD(Sport Sc))--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The purpose of this research was to gain insight into the sprinting of athletes with selected physical disabilities. The sprint performances of four Paralympic athletes (T43, T13, T37 and T38 classifications) were analysed in terms of variability in the biomechanics of their set position and in the kinematics of the initial acceleration phase and the maximal acceleration phase of their 100m sprints. The athletes also reported their perceptions about the potential of a rhythm training programme to influence their sprinting. A case study approach was used. Sprint kinematics were video-recorded four times over the training year. DartFish ProSuite software supported the digital tagging of anatomical landmarks and the calculation of the biomechanical features of the set position as well as the kinematics of each athlete. A subjective log was used to gather their perceptions about the rhythm training programme. There was variability in all aspects for all four Paralympic athletes. This should encourage coaches to help athletes find optimal kinematics in relation to their disability, rather than trying to coach them to a set template of an ideal form. Based on the kinematic data collected over all four test sessions, it appears that a coaching focus on stride length was the key to faster sprinting for this T43 (amputee) athlete. A coaching focus on stride frequency (once optimal stride length had been discovered) was the key for the T13 sprinter (visually impaired), and a coaching focus on stride frequency was the key to faster sprinting for both the T37 and T38 athletes (cerebral palsy). Although all of the athletes enjoyed the rhythm training programme, only the least experienced athlete (T38) reported that he would like to continue with this form of training. / AFRIKAANSE OPSOMMING: Die doel van hierdie navorsing was om insig rakende die naellooptegnieke van atlete met geselekteerde fisiese gestremdhede te verky. Die naellooptegnieke van vier Paralimpiese atlete (T43, T13, T37 en T38 klassifikasies) is ontleed. Die ontleding is gedoen met betrekking tot die veranderlikheid in biomeganika tydens hul gereedheidsposisies in die wegspringblokke asook in die kinematika van die aanvanklike versnellingsfase en die maksimale versnellingsfase gedurende hul 100m naelloopitems. Die atlete het ook hul persepsies rakende ’n ritmiese oefenprogram wat potensieël hul naellope kon beïnvloed gerapporteer. ’n Gevallestudiebenadering is gebruik. Beeldmateriaal van naelloopkinematika is vier keer gedurende die oefenjaar vasgelê. “DartFish ProSuite” sagteware het die digitale kodering van anatomiese punte ondersteun asook die berekening van biomeganiese eienskappe gedurende die gereedheidsposisie en die kinematika van elke atlete gefasiliteer. Daar is op ’n subjektiewe basis boekgehou van die atlete se persepsies rakende die ritmiese oefenprogram. Daar was wisselvalligheid in alle aspekte met betrekking tot al vier Paralimpiese atlete. Dit behoort as aanmoeding vir afrigters te dien om atlete te help om optimale kinematika in verband met hul gestremdheid te vind, eerder as om die atlete volgens ’n vaste templaat of ideale vorm te probeer afrig. Volgens die kinematiese data wat oor die loop van al vier toetsingsessies ingesamel is blyk dit asof ’n afrigtingsfokus op treëlengte die sleutel tot vinniger naellope vir die T43- atleet (amputasie) was. ’n Afrigtingsfokus op treëfrekwensie (nadat optimale treëlengte bewerkstellig is) was die sleutel vir die T13-atleet (visueel gestremd) en ’n afrigtingsfokus op treëfrekwensie was die sleutel tot vinniger naellope vir beide die T37- en T38-atlete (serebrale gestremdheid). Alhoewel al die atlete die ritmiese oefenprogram geniet het, het slegs die mees onervare atleet (T38) aangedui dat hy met hierdie vorm van oefening sou wou aanhou.

The purpose of the present study was to examine the time-course of mechanical power output and neuromuscular activity during fatiguing repeated-sprint exercise and recovery in man. Prior to the main study, we also investigated the reproducibility of power output during a single 6-s cycling sprint. For this study, eleven healthy moderately trained males performed a 6-s standing sprint on the front-access cycle ergometer on four separate occasions. The results of the study showed that reliable power outputs can be obtained after one familiarization session in subjects unfamiliar with maximal cycling sprint exercise. However, the inclusion of an extra familiarization session ensured more stable power outputs. Therefore, two trials should allow adequate familiarization with the maximal 6-s cycling test. For the main study, eight young moderately trained adult men performed an exercise protocol that consisted of ten, 6-s sprints on a wind-braked cycle ergometer interspersed with 30 s of recovery. After 6 min of passive recovery, five, 6-s sprints were repeated, again interspersed by 30 s of recovery. Peak power output (PPO) and mean power output (MPO) were measured during each sprint and EMG data (i.e., RMS) from the vastus lateralis muscle were also recorded. A one-way ANOVA with repeated measures (i.e., sprint number) was used to allocate the significant differences in each dependent variable over time. Analysis revealed a decline in power output during the fatiguing exercise that was accompanied by a decrease in EMG amplitude of the vastus lateralis muscle. Six minutes after the fatiguing exercise, power output during sprint 11 significantly recovered with respect to values recorded in sprint 10, but remained significantly lower than that recorded in the initial sprint. Thus, 6 min was insufficient to fully recover from the fatiguing repeated sprint protocol utilised in this study. The main findings in the present study were that: 1) the partial recovery of power output in sprint 11 was not accompanied by the recovery V of EMG amplitude; 2) similar mean power outputs were recorded during sprint 4 and 11 despite a significantly lower EMG activity recorded during the latter sprint; and 3) despite comparable mean power outputs during sprint 4 and 11, the decrease in power output over the next five sprints was greater for sprints 11 to 15 than for sprints 4 to 8.

This thesis comprises one review paper and five experimental studies, all of which are presented in the form of journal article submissions. These six research papers attempt to further our understanding of the physiological and metabolic requirements of repeated-sprint activity, specific to field-based team sports. Although coaches and sport scientists have suggested that repeated-sprint ability is an important fitness component of team sports, this area of investigation has only become more common in the past 10 years.