Review of Resisted Sled Towing for Sprint Training

fall over of Resisted Sled Towing for Sprint TrainingSprinting consists of three phases speedup phase, transition phase and a maximal speeding phase (Cronin Hansen, 2006). Acceleration is a major component in making a successful exploit in many different sports and it loafer also be seen as potentially pivotal in determining the outcome of a sports game. Therefore training for acceleration is an essential component of many athletes intensiveness and conditioning programme (Kraemer et al. 2000).When choosing systems to improve hyphening certain parameters need to be considered. The acceleration phase includes a nightlong stance conviction, increased trunk and knee flexion and greater propulsive forces (Kraemer et al. 2000). The muscular structure of the refuse nog needs to have the necessary capacity to devote to the acceleration performance and this is done done specific strength training activities. When an athlete improves strength, it produces greater force and fal ld ground edge time which increases stride frequency (Spinks et al. 2007). Various training modalities including elan loading improve the elastic energy during the book sage of the elan cycle, increasing stride length.Resisted elan training is a basic conditioning method used by coaches to lengthen running stride (Makarur et al. 2013). It is carried out by adding an external load to the athlete, such as pulling a tyre, a loaded sled, running up hill or utilize parachutes. Hunter et al. (2005) observed that running velocity and increasing strength are greatly increased by resisted sprint training due to the increased strength and power of the leg extensor muscles in the acceleration phase.This critical review will analyse previous studies and their findings when using resisted sprint training using plodding sleds on athletes.Lockie (2003) and Letzelter et al. (1995) stated that towing causes acute changes in sprint kinematics of acceleration phase. Certain dozens may be mor e appropriate for sprints performed from a block dismount compared to a standing start. Mero and Komi (1990) found mean contact time of foot to floor in the acceleration phase after a block start to range from 0.15s to 0.22s. This coincides with Spinks et al. (2007) findings of decreased contact time of first step of acceleration phase in the resisted sprint theme of 11.8% and recording 0.15s to 0.19s contact time.Spinks et al. (2007) also found that the biggest increase in overall velocity was achieved in the 0-5m interval. Rimmer and Sleivert (2000) found that carrying out 8 weeks of sprint and plyometric training improves the velocity over the first 10m of the sprint. However Kafer et al. (1993) canvass resisted sled training and found that there was a significant improvement of 0.35 seconds (PHarridge et al. (1998) found that resisted sled towing can alter myosin heavy chain expression of muscle fibres. Increases in speed occur due to a shift in fibre type distribution and sp eed of shortening cycle which might contribute to increased power generation. 8.4% significant increases were found on resisted sprint trained athletes when compared to a control group (Spinks et al. 2007). If power output of knee extensors are increased, improved ground contact time results in greater propulsive acceleration efforts. However Maclean () disproved this as he found that after testing this hypothesis crossways 6 weeks of training increase in muscle performance occurred without any significant change in myosin heavy chain or fibre type distribution.Letzelter et al. (1995) after conceiveing 16 female sprint performances found that performance was decreased by 8% and 22% respectively for the loads of 2.5 kg and 10 kg. Results showed that this was predominantly due to the reduced stride length in athletes. drop-offs in stride length by 5.3% and 13.5%, stride frequency 2.4% with 2.5 kg load and 6.2% with a 10 kg load. Across all loads were found to be an increased stance time to lean and hip flexion angle. Lockie et al. (2003) reported connatural findings when testing 20 males field sport athletes. Athletes performed 15m sprints using no resistance, 12.6% or 32.2% of body mass load. These were chosen as previous findings show a decrease in 10/20% of max velocity. Decrease in stride length of 10% +24% were documented. Stride frequency was only found to decrease by 6% in each load. In agreement with Leztler et al. (1995).Makurak et al. (2013) found running stride length increased in their resisted sled training group when compared to the standard training group. Findings were also supported by Delecluse (1997). Increasing stride length is said to be the result of performing fuller extension at the knee found by the increased knee angle at toe off. This change could be directly due to the strength between hip and knee extensors.Bhowmick and Bhattacharyya (1988) suggest the horizontal acceleration of the fort swing increases stride length and during ground contact time the vertical element enhances the leg drive. Ropret et al. (1988) tried adding load to the athletes sections however no significant reduction in sign acceleration over 30 m was found. Lockie et al. (2003) state that 32.2% body mass was better for the development of swiftness body action. As the load increases shoulder range of motion increases. However Spinks et al. (2007) in terms of their study of upper-body kinematics found that it had little impact on acceleration performance.The critical analysis of various studies showed that results were contradictory. More investigations into optimum load, changes in strength shortening cycle and training distances should be undertaken to find ideal training focus.ReferencesBhowmick, S., Bhattacharyya, A. (1988) Kinematicanalysis of arm movements in sprint start. journal of Sports Medicine and Physical Fitness Vol 28 pp315323.Cronin, J., Hansen, K. (2006) Resisted sprint training for the acceleration phase of sprinti ng Journal of Strength and teach Vol 28 (4), pp.42-51Delecluse, G. (1997) Influence of strength training on sprint running performance Current findings and implications for training Journal of Sports Medicine Vol. 24 (3), pp.147-156,Harridge, S.., Bottinelli, R., Canepari, M., Pellegrino, M., Reggiani, C., Esbjornsson, M., Balsom, P.,Saltin, B. (1998) Sprint Training, In Vitro and In Vivo Muscle Function, and Myosin Heavy Chain Expression. Journal of Applied Physiology Vol84 pp.442-449.Hunter, J., Marshall, R., McNair, P. 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