Guidelines For Designing Experiments On Performance Optimization Of A Sprinter

Recognition of and statement of the problem

Performance of a printer is measured by the time taken to complete a sprint run.  The objective of the study was to minimize the time taken by the athlete to enhance his performance on the field the level of the significant factors affecting the completion time of a sprint Run where measured in two levels (Halson, S. L., 2014).  For positive effect the replicates were assigned +1 and for negative effects -1.  The entire experiment took place in a nearby field of the University Campus.  A 200m track was prepared for the sprint Run and the participants were informed about the characteristic of the field.  In the pre-experimental setup the outline of the study was drawn and selection of the response variable along with the decision factors was finalized.

The main objective was to optimize the sprinting time of the sprinter. The minimization of time and completion of the race with high level of energy were two major aspect of a sprinter (Rumpf et al., 2012).

The design of the study was based on 3 factors of the sprinter.  The physical factor was taken as sleep, mental preparation was taken as the psychological factor and environment was taken as the external factor (Hollings et al., 2012).  The study was conducted for 2 days in the morning session from 5 a.m. to 7 a.m. The positive aspect of the factors was taken as +1 in the study to analyse the optimistic effect of these factors. The subjects were advised later based on this assumption which contributed to the optimization (minimization) of the adverse effects.

1. Physical factor:   Sleep

The sprinter can take the field in the morning session.  The experiment was performed for two scenarios.  On the first day the subject came to the field after 8 hours of sleep at night.  Second day the sprinter came to the field after 4 hours of sleep in the previous night (Venter, R. E. (2012). The extra hours of sleep was taken as positive factor in raw data.

2. Psychological factor:  Absence of mental preparation

The sprinter on the first day came to the field without any knowledge of the experimental conditions though well aware of the scope of the study. On the second day he was he was well aware that 200m sprint will be conducted with other participants and mentally prepared for the same. Absence of preparation was taken as negative factor in the study.

Selection of the response variable

3. Physical factor:   Training

For a sprinter physical training is the main way of preparation for the race.  On both the days sprinters took a training session which was arranged under the guidance of a trainer. The subjects went through 15 minute session with static stretching explosive muscle building and calf muscle strengthening exercises (Chaouachi et al., 2010). In second exercise session under the trainer subjects relaxed the muscles with light weight lifting and then in the second session there were ask to attend a 15 minutes swimming session (Gee, C. J., 2010). On the second day sprinters were allowed to take part without rigorous exercise periods. This training was taken as positive factor in the study.

4. External factor: Environment

Other factors like weather condition of the day  and dress of the participant Where are not taken into consideration and considered to be noise factors for the study and hence  2 days where chosen for different weather conditions and participants allowed to wear formidable clothing of their own on both of the days for eliminating the effect of these factors.

Day 1 was chosen on a day with clear sky and less humidity.  Day 2 the experiment was chosen on a day cloud covers and 80% humidity.  Humidity effects the environment and athletes generally prefer a sunny day with low level of humidity for maximum output.

Objective of the study was to optimize the factors under the scope of the study for the sprinter.  The time taken by the sprinter to complete 200 meter sprint was measured on both the days which (time) was later selected as the response variable (Mendez-Villanueva et al., 2011).  The minimization of the response time of the sprinter was the ultimate goal.

Design of the experiment was constructed in such a manner that can minimize the noise level especially the environment effect and clothing choice of the sprinter.  Two physical factors and one psychological factor were considered to measure the response variable’s completion time for sprinting 200 meters.  The study conducted was conducted to collect 16 set of data. Therefore a total of 8 effects were studied effectively for 2 days. The study also evaluated the effect of two main factors and three factors together.

The number of replicates was decided from the design of the study and for this analysis two replicates per factor was taken which can explain the response variable.  A total of 8 observations of two replicates each were taken to summarize the model. The total data set has been given in appendix.

Choice of factors, levels, and range

The spring event organized Indian nearby field with 200m sprint in tracks.  There were 5 parallel sprinting tracks for the purpose of the study.

The event started from morning 5 a.m. with training session of the sprinters this printing event started from 6 a.m. in the morning this printers were given rest for 30 minutes after the training session they were provided protein supplements and chocolate shake energy drink where provided to the participants after the sprinting session the time taken by the participants to complete the 200m sprint was recorded manually using a digital stopwatch for accurate measurement of time three referees present  with their own stop watches sports Doctor was present from morning 5 a.m. and he measured the basic physical parameters of the participant after the sprint.  The participants were transported to the University Campus at 7 a.m. in the morning.

The analysis was done using g-power and Minitab packages.  There were three set of hypothesis for the model of the study.

Set1: H₀: The means of each replicate are equal.

H₁: The means of the replicates are unequal.

Set2:   H₀: The means of each factor are equal.

H₁: The means of at least one of the factor is unequal.

Set3: H₀: There is no interaction between the replicates and factors.

H₁: There is interaction between the replicates and factors.

The collected data set was tested in Minitab for normality and the results, the graphs found the time data to be normally distributed.  The normal plots have been provided in the appendix section.

The half normal plot has been included in the appendix and it is observed that the three factors, sleep and physical training and mental training were significantly not normal.  These three factors were not distributed with zero mean and constant standard deviation. Hence decision was taken to include these three variables to explain the response variable, time, required by the sprinter to complete a sprint of 200m.  The noise factor which was obtained from the nature of the environment was not included in the study of the sprinter model.

Normal graph for the response variable and the decision variables are given in the appendix it was observed that physical variables sleep and training along with the psychological variable of mental training where found to be not normal the noise factor was studied from the normal graph and excluded from the model.  Due to significance of the three effect factors which was evident from the P values there interaction for 2 and 3 levels were included ANOVA. Other external factors such as errors of the referee in choosing the correct winner or error in recording of time were excluded from the scope of the model.

Choice of experimental design

The initial ANOVA table included all the variables and their interactions. It was observed that the P values of the interactions were are not significant and the final ANOVA was constructed on the two physical variables, sleep and training along with the psychological variable which was mental training.   Both the ANOVA tables have been included in the appendix.

From the analysis of variance it was observed that the P values were all zeros. This established the claim that there were only 3 significant decision variables.  The F value for sleep was 22.55 and for training type F value was 60.31. The F value for mental preparation was 34.88. The residuals or the errors had 12 degrees of freedom. The  initial model with all the variables and 9 degrees of freedom and the final model of regression had 3 degrees of freedom with F value of 39.25.   The adjusted R squared value of 86.39% was very close to original value of R square, which was 92.74%.  Hence it was evident that the model was well explained by the significant effect factors.  This model was finally approved for regression analysis with three significant factors. The null hypotheses were rejected based on the p values of the regression model.

The final regression model was evaluated by Minitab software package and is given below.

Time to 200m (seconds)

=

29.903 – 1.318 Factor1_ sleep – 2.156 Factor2_ training type – 1.639 Factor3_ mental preparation

The regression model explained the entire study. It was evident from the regression equation that sleep and physical training along with mental preparation were affecting the sprinters performance. The coefficients of the regression model were entire negative where the Intercept was the only positive quantity.   Hence with better training and proper rest the sprinter could perform exceptionally well.  Psychological or mental training was also a necessary factor for the rejuvenation purpose which also affects the performance of a sprinter. Hence reduction in sprinting time was possible from increase in significant factors.

The normal plot of the residuals explained that residuals where almost normally distributed.  The residual plot has been included in the appendix.

Residuals versus fits graph were examined and scatterings of the data were observed from the plot. It was kept in mind that sample size for the experiment was only 16. Hence the scattering of the residuals was well explained.

Residuals versus run order graph was also scattered in nature but had a pattern which was not present in the fit graph. A shape was observed by keen observation and the shape was found to be of the letter S. residuals versus run order graph was also placed in appendix.

Performing the experiment

Three graphs for residuals with significant factors were drawn during regression analysis. The residuals for the factors were found to be normally distributed with mean zero and constant standard deviation. These graphs were also included in the appendix section.

Histogram of residuals was placed in appendix section. This histogram was drawn during regression process which also indicated normalness of the residuals.

Conclusion

The ANOVA model gave that the F value for regression model was 39.25 with zero p value. The model was found to be well explained and significant in nature. The predicted R square value was 83.56% and the adjusted R square was 88.44%. Hence both the values were very close which indicated that irregularities were almost not present in the model.

The interval plots for the three factors for two noise levels were also done in Minitab and the combined graph has been placed in the appendix. The graphs explained the regression model and hence increment in the decision variables was advised for better results in timing of the sprinter. The normal and half normal graphs for the sleep and training along with psychological or mental preparations along with the P values  indicated the significance of the model variables and two level and three level applications were found to be non significant.

The final results of the study supported the fact that extra hour of sleep enhances performance in a sprinter as it relaxes the muscles and helps to concentrate on the physical training part.  The rigorous physical training under the observation of a well trained trainer always sharpens the skill of a sprinter and the time factor gets optimized (Halson, S. L., 2014).  The psychological training nowadays is the most important part of the performance factor of any athlete. In the study a positive relation was found between the psychological training decreases timing to complete a sprint of 200m.  Hence the result was in support of the earlier research works (Fullagar et al., 2015).

The negative correlation of the of the time taken by the sprinter to complete the race with the significant factors indicated that performance was announced by  taking extra hour of sleep in the night or by rejuvenating the mind by attending the mental workshop after the physical training session (Milewski et al., 2014).  Relaxation, less anxiety and stress can enhance the performance of an athlete significantly.

From the analysis and modeling of the collected data, the sprinters were advised to follow disciplined routine.  Extra hours of sleep was advice to them, morning physical exercises along with rigorous training sessions followed by mental training workshop were also  suggested by the experimenter (Iaia, F., & Bangsbo, J., 2010).

Statistical analysis of data

Under the current study the noise factors where neglected and environment factor was one of them.  It has to be noted that environment plays an important role in the performance of any athlete.  High level of humidity with adverse weather conditions negatively impacts the performance level.  In the current study the athletes featured to take part in the sprint of 200m.  This was a limitation of the study considering the fixed size of a track (Morin et al., 2012). Variability and track length could have provided a better scope for the study.  The dress and shoes are also important external factors in the performance of a sprint runner.  In future study inclusion of these factors enhances the test results for a better regression model.

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