Sprint Kinematic Performance Changes upon Returning from a Declining Period in Track and Field Sprinters

Sprinting is a key component of many competitive sports. Coaches regularly seek ways to improve their athletes’ sprint performance in order to improve their sports game performance. Sprinting is a complex movement pattern that has many different subcomponents to be properly trained in order to become faster. A sprint event has three major phases (acceleration, maximum velocity/constant speed, and deceleration). Coaches are constantly looking to improve their athlete’s performance. This is done by a strategic training regimen that extends throughout the entire year. During the off-season, the coaches’ main focus is to maintain conditioning and performance adaptions. Previous studies have concluded that detraining has a negative impact on many aspects of an athlete’s performance profile. In 2020 many sports were disrupted completely in the cause because of Corona Virus. Research on unplanned detraining/reduced training has not been explored. In the proposed study, we aim to evaluate the progression of division 1 track athlete\u27s sprint performance from a deconditioned state to in-season shape. Coaches regularly seek ways to improve athlete sprint performance, including sprint kinematics, in efforts to translate to superior sport performance. This is generally done through a periodized training program application. This past year the COVID-19 virus significantly altered/halted many aspects of sports performance training. This specifically impacted the off-season training of Division 1 track and field athletes. PURPOSE: To examine the magnitude of change in sprint performance kinematics of Division 1 sprinters after participating in a training program upon returning from a COVID-19 pandemic enforced deconditioning period. METHODS: Thirteen Division 1 sprinters participated in two separate testing sessions 5 months apart (October 2020, February 2021). Initial testing was conducted with athletes returning in a deconditioned state resulting from COVID-19 quarantine. The second testing session was completed after a typical training in-season program. Athletes performed two trials of a 30-meter sprint-through. The sprint-through test was conducted over a 60-meter distance with the first 30 meters used for acceleration and the subsequent 30 meters being the timed zone. Athletes were instructed to attain maximal velocity upon entering the 30-meter timed zone. Speed was obtained by timing gates placed at the start and end of the 30-meter timed zone. Within the 30-meter timed zone, 6 meters of the OptoJump Next measuring system, placed in the middle of the 30-meter zone, captured sprint kinematics (stance phase, contact time, step length, stride length, and flight time, speed,). A series of paired sample t-tests were used to find differences in sprint kinematics between time points. The significance level was set at 0.05. A questionnaire was given to the athletes in order to assess the training they were performing during the lockdown. RESULTS: Significant differences were found in left stance phase of 19% from pre ( 0.119 0.0159) to post (0.1 0.03) (t (12) = 2.918; p = 0.012; Cohen’s D = 0.76; Moderate). Other variables that showed no significance were speed (t(12) = 0.37; p = 0.710;), step length (t(12) = 1.33; p = 0.207), stride length (t(12)= 1.33; p = 0.207), and flight time (t(10)= 0.875; p = 0.401). CONCLUSION: After a 5-month training program following a period of detraining, improvements were seen in the stance phase and contact time in Division 1 track and field sprinters. PRACTICAL APPLICATIONS: Monitoring sprint performance kinematics after deconditioning can help aide strength and conditioning coaches to plan training programs to improve sprint kinematic performance