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Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase.

Martínez-Valencia MA, Romero-Arenas S, Elvira JL, González-Ravé JM, Navarro-Valdivielso F, Alcaraz PE - J Hum Kinet (2015)

Bottom Line: Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition.The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s-1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s-1, p ≤ 0.01).Otherwise, no significant increases were found in Fpeak and TRFD.

View Article: PubMed Central - PubMed

Affiliation: UCAM Research Center of High Performance Sport, San Antonio Catholic University of Murcia, Guadalupe, Murcia, Spain.

ABSTRACT
Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s-1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s-1, p ≤ 0.01). Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

No MeSH data available.


Related in: MedlinePlus

Force-time trace for start in sled-towing exercise, illustrating the start of the sprint, the RFD and Fpeak
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f2-jhk-46-139: Force-time trace for start in sled-towing exercise, illustrating the start of the sprint, the RFD and Fpeak

Mentions: In order to record the sprint times over 30 m, a photocell system (DSD Lasersystem, DSD S.L., Leon, Spain) was placed at 0 m, 20 m, and 30 m. The load cell recorded changes in force production during the first step, when the athlete started to run. The force-time traces for the sprints were analyzed to obtain three dependent variables: Fpeak, RFDpeak and TRFD, all in the first step. The RFDpeak corresponded to the steepest gradient of the force-time curve over a 0.02 s period (RFD = ΔF·Δt−1). The TRFD was obtained by finding the time difference between the start of the sprint and the beginning of the RFDpeak. The start of the sprint was defined as the point where the force reading was greater than the average force when the subject was static in the starting position (Figure 2).


Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase.

Martínez-Valencia MA, Romero-Arenas S, Elvira JL, González-Ravé JM, Navarro-Valdivielso F, Alcaraz PE - J Hum Kinet (2015)

Force-time trace for start in sled-towing exercise, illustrating the start of the sprint, the RFD and Fpeak
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519204&req=5

f2-jhk-46-139: Force-time trace for start in sled-towing exercise, illustrating the start of the sprint, the RFD and Fpeak
Mentions: In order to record the sprint times over 30 m, a photocell system (DSD Lasersystem, DSD S.L., Leon, Spain) was placed at 0 m, 20 m, and 30 m. The load cell recorded changes in force production during the first step, when the athlete started to run. The force-time traces for the sprints were analyzed to obtain three dependent variables: Fpeak, RFDpeak and TRFD, all in the first step. The RFDpeak corresponded to the steepest gradient of the force-time curve over a 0.02 s period (RFD = ΔF·Δt−1). The TRFD was obtained by finding the time difference between the start of the sprint and the beginning of the RFDpeak. The start of the sprint was defined as the point where the force reading was greater than the average force when the subject was static in the starting position (Figure 2).

Bottom Line: Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition.The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s-1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s-1, p ≤ 0.01).Otherwise, no significant increases were found in Fpeak and TRFD.

View Article: PubMed Central - PubMed

Affiliation: UCAM Research Center of High Performance Sport, San Antonio Catholic University of Murcia, Guadalupe, Murcia, Spain.

ABSTRACT
Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s-1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s-1, p ≤ 0.01). Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

No MeSH data available.


Related in: MedlinePlus