Use of resistance with sprint training
Issue: Volume 28 Number 3
As with any type of training stimulus, the general principle of overload is an integral component in promoting adaptation to training. For example, in resistance or endurance training, coaches vary volume and intensity throughout the program (providing overload through these variables) in order to create desirable adaptations.
Historically, weighted resistance has been used sparingly in sports conditioning as a means to provide overload during sprint running. However, over the past decade, particularly in North America, resisted sprinting has become commonplace. Of particular note, this training trend is being applied to a broad age range of athletes, including pre-adolescents.
Generally, overloaded, resisted sprinting is accomplished by using weighted sleds, parachutes or stretch cords. Several questions remain unanswered in regards to resisted sprinting. Of primary interest to the coach is whether or not the inclusion of resisted sprinting leads to improved performance. Furthermore, if this training method is useful in improving performance, it is unclear as to how suitable this training method is with various developmental levels of athletes. Another important consideration is the relative level of volume that should be undertaken with resisted sprint training (for example, 10 per cent of total sprint training).
In a brief overview of the research literature, Sheppard (2004) concluded that resisted sprinting should be limited to physically mature athletes with well-refined sprint technique. This conclusion was based on concerns for the biomechanical changes that resistance imposes on the athlete (Knicker 1994), and the likelihood that training under these conditions extensively will retard performance through undesirable changes in sprint biomechanics.
Further, it was suggested by Sheppard (2004) that the fundamental philosophy behind resisted sprinting may be flawed. Essentially, resisted sprinting is conducted in an attempt to impose a resisted overload that is highly specific to sprinting (in comparison to other types of resistance training). However, because the resisted load considerably alters the biomechanics of the sprint (increased ground contact time, increased knee flexion during foot-strike and increased forward lean), this would negate any specificity of the resisted load. In addition, training with high volumes under resisted conditions may manifest into longer-term technical errors in sprint kinematics, thereby having a negative impact on performance under un-resisted conditions.
As a case study, a high-performance rugby athlete undertook performance measures (time) and video assessment (Swinger Software, Melbourne) of un-resisted and progressively resisted sprint conditions for a 30-metre sprint. As Table 1 illustrates, the resisted load condition imposed considerable stresses on the athlete, resulting in considerably different sprint times to that of the un-resisted condition. With this in mind, coaches may want to temper the balance between the potential benefit of applying resistance to the sprint action, and the potential negative effects of training at increasingly slower speeds.
Furthermore, video analysis revealed considerably longer ground contact times and increased knee flexion at ground contact as the resisted load increased. Intuitively, we can assume that the force produced by the athlete would be greater as the resistance increased. However, successful sprint training has generally focused on training at or very near the movement velocities, with the same movement kinematics (joint angles, ground contact times, etc.), as sprinting that is specific to the sport (for example, track and field running style, rugby running style). As the resisted load increased, the nature of training was increasingly dissimilar to that of un-resisted sprinting.
In conclusion, we propose these considerations for resisted sprint training:
- Resisted sprinting should be used sparingly, as it has been shown that even after resisted sprint training, changes in sprint kinematics occur, such as an increase in ground contact time. Coaches should carefully monitor sprint kinematics so as to avoid imposing unwanted changes on sprint running technique.
- Resisted sprinting should not be used with developmental athletes. The developmental athlete population is able to increase force capabilities from general strength training methods and, therefore, utilisation of special resistance methods early in their development is unnecessary. Furthermore, developmental athletes have not refined and ‘hardened’ their sprint technique, thus, resisted sprinting will likely undo or interfere with proper technical development of sprinting.
- Coaches may choose to experiment with the use of different methods of resisted sprinting than those currently popular, such as sleds and parachutes. For example, using a slight head-wind as resistance may allow an athlete to train with more appropriate technique as the resistance is imposed across the athlete’s entire frontal surface area, including the limbs (rather than an attachment on the hips which loads a specific point of the body).
- For sports that require sprinting against external forces, it is likely that sport-specific resisted sprint training can be better replicated in comparison to sleds and parachutes. For example, a bobsled athlete (or rugby forward) could push an automobile or specific apparatus rather than towing a sled.
Table 1: Increases in 30-metre sprint time with increased resisted load
Load un-resisted Time to 30 metres Increase
| Load (kg) | Time to 30 metres (sec.) | Increase (%) |
| Un-resisted | 3.60 | - |
| 13.5 | 4.16 | 15 |
| 18.0 | 4.52 | 25 |
| 22.5 | 4.74 | 32 |
| 27.0 | 4.85 | 35 |
| 31.5 | 5.08 | 41 |
| 36.0 | 5.58 | 55 |
References
Knicker, AJ 1994, Untersuchungen zur ubereinstimmung von zugwiderstandslaufen und sprintbewegungen, paper presented at the Widerstandbelastungen im Schneligkeitstraining, Koln, Germany.
Sheppard, J 2004, ‘The use of resisted and assisted training methods for speed development: coaching considerations’, Modern Athlete and Coach, 42(4), pp. 9–13.
