Something that is missing from a lot of people’s workouts is speed. This is a problem because if you train slowly you’ll be slow.
Two of the best ways to get faster and develop a quicker first step are with full squats and weighted sled training. Both exercise maximize concentric power output, which is significantly related to sprint acceleration and peak running speed over short distances.
A study published in the European Journal of Applied Physiology tested the relationship between sprint speed with power and force output in a traditional jump squat and a split jump squat in elite male power athletes. Results showed that the athletes who could produce the most concentric power in both squat versions had the quickest 5-meter sprint times. Peak force in both lifts also was associated with sprint start time.
Peak power output was maximized with loads between 40 and 50 percent of the 1RM for the jump squat, whereas peak force was highest with 70 percent of the 1RM, which was the heaviest load tested.
Researchers suggest that being able to produce high force correlates with start speed because a quick first few steps require the body to be accelerated rapidly from stationary. The ability to produce maximal power correlates with the ability to pick up speed once the body is in motion.
You can improve both by doing a training cycle that includes full squats for strength, followed by a lower body power training cycle that maximizes concentric power output.
Weighted sled training is a great way to do this. For example, when national team sprinters did a weighted sled program for 4 weeks they had greater increases in acceleration than following a traditional training program. Training with the sled increased ground contact time during free sprinting, which allowed the athletes to apply more force with each step. Stride length increased by 2.7 percent after sled training, and they improved maximal speed by 1.3 percent, which is a large amount in highly trained elite sprinters.
Researchers recommend weighted sled training be included once a week in a 4- or 5-day-a-week weight-training program. To increase running speed, do weighted sled runs of 15 to 25 meters—any further and running form deteriorates.
Try pairing a 15 or 20-meter sled run with regular sprinting to take advantage of the fact that the lower body muscles are already activated. This will also reinforce correct running mechanics—just like if you are going to train heavy partial squats in the gym, you need to perform a set of full-range squats at a lighter weight so as not to compromise range of motion.