Optimizing the load for peak power and peak velocity development during resisted sprinting

Introduction: Resistance towing is perhaps the most specific form of developing strength and power in muscles involved directly during the start, acceleration and at maximum speed. Resisted sprint training may involve towing a sled which provides an overload through the friction between the sled and ground surface or a modern advanced training device which uses drag technology to provide fully controlled resistance during the movement, such as the 1080 Sprint. The main objective of the study was to evaluate the optimal loading for the development of power in the engine assisted drag technology system SPRINT 1080. Material and methods: We evaluated the changes in running velocity and the generated force and power during resisted sprints over 30m with a load of 1, 3, 6, 9, 12 and 15 kg. Seven male sprinters with national and international experience participated in the study. Their average age, body mass and body height were 22.2 ± 2.4 years, 77.43 ± 4.63 kg, and 178.6 ± 3.2 cm, respectively. All athletes performed six 30 m sprints with 5 min rest intervals in between. The first sprint was performed without additional resistance, while the remaining 5 were performed in an random order with additional resistance of 3, 6, 9, 12 and 15 kg. After receiving a verbal signal, the participant started at will from a semi crouched position. During the resisted sprint trials, the time [s] and the following variables were recorded in peak values: power output [W], generated force [N], and sprinting velocity [m/s]. Results: Our results show that loading with 6 kg decreased sprinting velocity by 9.37% while the generated horizontal power increased by 31,32%. The 6 kg loading on the Sprint 1080device corresponded to 8% body mass, yet as mentioned before the baseline results were not fully free sprinting as the tested athletes reached velocities 0.5-0.6 m/s greater without the harness. Conclusion: Taking into account this fact, our results seem to confirm previous findings, that external loads between 8 and 13% may be optimal for improving power and sprinting speed at the same time.

Assessing Horizontal Force Production in Resisted Sprinting: Computation and Practical Interpretation

The assessment of horizontal force during overground sprinting is increasingly prevalent in practice and research, stemming from advances in technology and access to simplified yet valid field methods. As researchers search out optimal means of targeting the development of horizontal force, there is considerable interest in the effectiveness of external resistance. Increasing attention in research provides more information surrounding the biomechanics of sprinting in general and insight into the potential methods of developing determinant capacities. However, there is a general lack of consensus on the assessment and computation of horizontal force under resistance, which has resulted in a confusing narrative surrounding the practical applicability of loading parameters for performance enhancement. As such, the aim of this commentary was twofold: to provide a clear narrative of the assessment and computation of horizontal force in resisted sprinting and to clarify and discuss the impact of methodological approaches to subsequent training implementation. Horizontal force computation during resisted sleds, a common sprint-training apparatus in the field, is used as a test case to illustrate the risks associated with substandard methodological practices and improperly accounting for the effects of friction. A practical and operational synthesis is provided to help guide researchers and practitioners in selecting appropriate resistance methods. Finally, an outline of future challenges is presented to aid the development of these approaches.

Acute effect of resisted sprinting upon regular sprint performance

The aim of this study was to investigate the acute effect of resisted sprinting upon running sprint performance. Thirty male athletes from track and field (age: 21.2±2.9 yrs, body mass: 69.8±9.8 kg, height: 1.75±0.08 m) performed two different test sessions (one day of 7×60 m runs alternating between regular and resisted sprinting and the other day 7×60 m of regular sprints) with 5 min between each run. Sled towing individually weighted to 10% of each participant’s body mass was used as resistance for the resisted sprints. It was found that training with or without resistance had the same effect; there is no acute effect of resisted sprinting upon sprint performance after using resisted runs. It was concluded that resisted sprinting does not have any acute positive effect upon regular sprints of 60 m, but only a fatiguing effect.

THE IMPACT OF ASSISTED SPRINTING TRAINING (AS) AND RESISTED SPRINTING TRAINING (RS) IN REPETITION METHOD ON IMPROVING SPRINT ACCELERATION CAPABILITIES

The purpose of this research is to determine the impact of assisted sprinting training (AS) and resisted sprinting training (RS) in repetition method on improving sprint acceleration capabilities. This research used experimental method in pre-test and post-test design. The research sample were twelve male collegiates track sprinters, athletic division Indonesia University of Education, Bandung. Six male collegiates track sprinters for AS and six male collegiates track sprinters for RS. It used simple random sampling. The instrument used is 30 m sprint test. After training three times per week for six week, data were obtained from pre-test and post-test processed statistically by t-test. The AS group and RS group showed significant changes on improving sprint acceleration capabilities. No significant different between AS and RS on improving sprint acceleration capabilities. In AS the increase is better than RS at a distance of 10 m from a distance of 30 m. While, in RS the increase is better than AS at a distance of 10-20 m and 20-30 m from a distance of 30 m. Accordingly, to improve acceleration at a distance 10 m use AS, while to improve acceleration at a distance of 10-20 m and 20-30 m from a distance of 30 m use RS.

Appropriate Loads for Peak-Power During Resisted Sprinting on a Non-Motorized Treadmill

The purpose of this study was to determine the load which allows the highest peak power for resisted sprinting on a non-motorized treadmill and to determine if other variables are related to individual differences. Thirty college students were tested for vertical jump, vertical jump peak and mean power, 10 m sprint, 20 m sprint, leg press 1 RM, leg press 1 RM relative to body weight, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM. Participants performed eight resisted sprints on a non-motorized treadmill, with increasing relative loads expressed as percent of body weight. Sprint peak power was measured for each load. Pearson correlations were used to determine if relationships between the sprint peak power load and the other variables were significant. The sprint peak power load had a mode of 35% with 73% of all participants having a relative sprint peak power load between 25-35%. Significant correlations occurred between sprint peak power load and body weight, lean body mass, vertical jump peak and mean power, leg press 1 RM, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM (r = 0.44, 0.43, 0.39, 0.37, 0.47, 0.39, 0.46, and 0.47, respectively). Larger, stronger, more powerful athletes produced peak power at a higher relative load during resisted sprinting on a nonmotorized treadmill.