Measuring what Matters Part 2- Acceleration
By Carl Valle
In terms of time contribution, acceleration is a major contributor to the performance in a 100m race, but technically only a quarter of the time in a 200m race. The sport of sprinting has evolved in a way which requires having a complete race, not just being excellent in one facet of that race.
While the 50-60m sprints are primary acceleration only, success in the later part of those races will likely come from simply faster athletes. Being the first part of the race, acceleration and starting will naturally get attention or sometimes be thought of as the “frosting on top.” Regardless of the investment into developing acceleration you should measure progress in it annually, and the most common distance is 30m, but anything from 10m-60m can be used.
Timing Acceleration in Practice
Setting up testing for acceleration is not complicated, but it does take some organization in order to do it properly, especially when you have large groups and limited equipment like starting blocks.
Another problem with acceleration is the need to get into a consistent method of repeating the sprint itself, with some athletes having great block mechanics all the way to the freshman in high school who can’t do a crouch start. Over the years I have been convinced that coaches need to sequence their program better so we don’t lose practice sessions because of administrative burdens that could be alleviated with better team management. Each year the same problems are likely to occur and it’s up to the coach to try to make the next session one step better.
Starting Position Options and Considerations
Sprinters and other speed athletes have many different options when timing, but each option has specific caveats that must be carefully weighed. The most important factor when choosing a starting position is consistency and repeatability. Many athletes at the lower levels shouldn’t use blocks at all, while blocks may be the only way to test for advanced sprinters in the SPP. Listed below are the four primary options of starting, listed general to specific and including key benefits.
Standing Starts- The standing start is sometimes used with longer sprints and, at times, with jump work. Standing in a narrow split stance is a simple way to create an acceleration position, but the athlete will accelerate for a shorter distance in the repetition, as they are more vertical in their posture. It’s not a great method to help intermediate and advanced athletes develop block clearance, but It’s good to help transition periods from deep acceleration to top end mechanics. Sometimes a small bend in the lean at the waist is acceptable, but don’t have the athlete dependent on being bent over to create the acceleration.
Crouch Starts – The crouch start is technically a standing start because only two contacts are made with the ground, those two being the feet. The difference is that the lean and bend at the hip as greater than the standing start. Also what is important is the “C” in crouch, meaning a convex curve to the spine is used. The Crouch start can leverage rolling starts for some situations but many times they are convenient ways to accelerate in runs where the total volume of running is more than a factor than the actual times. Crouch starts are useful for sleds and hill sprints to either remove slack on the cord (sled) or have a consistent starting position for hills.
Three Point- When one hand makes contact with the ground, the crouch start becomes a three point start. Another difference between three point starts and crouch starts is that the three point position is mainly static. This means a rolling motion is rarely used and they produce similar times to those sprints that use blocks. While similar to blocks because they are in deep joint angles, they are much different mechanically in leg contribution and must be considered a separate option. They should not be compared interchangeably to block times.
Starting Blocks- I have seen some athletes improve 10m times greatly but fail to transfer that in races or even 30m time segments. The purpose of the blocks is not just to get a great “start” but to set up the race for a great performance or time. It is imperative that coaches focus on good starting abilities before being trapped in the biomechanical demands of the starting position. With developmental or unskilled older athletes, sometimes a good crouch or three point start will teach better overall acceleration then to start off with major mistakes that can create poor habits.
For more information on starting blocks, read: Young Sprinters Struggle With Erectile Dysfunction.
Most athletes in practice need to start when they are ready, but limit their time to minimal preparation in order to prevent the “brain freeze “ from allowing too much time for overthinking. When doing any type of start you tend to have the three following options:
Athlete Initiation – When athletes go when they are ready is a valuable way to start a sprint. Most athletes like this and this approach is valuable on longer sprints and early in the season when being gun ready is not as important as doing the mechanical demands correctly.
Reaction Initiation – After athletes are able to execute the acceleration properly, a sound stimulus is appropriate for getting them ready for competition. While simple at first, reacting to a sound requires a lot of practice. It’s suggested that sprinters who are developmental get a lot of practice with various pauses so they don’t create a habit of anticipating the gun. With the false starting rules in place presently, an entire generation of athletes have to prepare for reacting to sounds with various pauses versus anticipating the gun.
Group Practice – Lining up next to other athletes in narrow lanes creates a very unique psychological challenge to sprinters. Two major challenges are the obvious: the temptation to want to get out “faster” than the other competitors, and racing the people next to you by responding to their position during the race. Exposing athletes to group starting practice helps prevent false starts and the ability to execute when feeling the “heat” next to you.
Selecting the Right Distance to Measure
While the classic 30m distance is the most popular for evaluating acceleration, the reality is sometimes other distances such as 15m or even the 50m or longer options are good ways to gage training. Each distance has pros and cons, and it’s up to the coach to select the most appropriate length to gage development.
10-15m– One must be careful to focus on very short distances because athletes tend to use up way too much energy resources trying to get a good time in the short tests so they don’t replicate what they do in races. Sometimes the opposite is true, a lot of short sprint habits from practice poisons the race when an athlete tries to muscle out the run. I like 10m for block clearance analysis and 15m for more of a training effect.
20-25m– The great benefit of the 20-25m training distance is that the coach can see drop off from fatigue without risking injury. Since effort may be high but the velocities are still submaximal compared to top speed work, athletes can challenge their capacity to challenge nervous system stress with repeat bouts. In addition to early season work, coaches can use the 20-25m range for in-season work as it’s less taxing than the longer runs with weekly competition.
30m – The classic distance many coaches feel comfortable when testing acceleration is the 30m from blocks. Since the 30m acceleration provides three 10m splits, (provided timing equipment is used) one can get a nice view of the primary phase of acceleration. Due to the popularity of the distance, many coaches are lured into comparing the 30m to the tables found at coaching education sources, but those are not necessarily practice times and some reflection is necessary to see progress.
40-60m- The longer sprint distances are great for seeing the bigger picture with the the transition from 30 meters plus. However, they do come with the associated fatigue and injury risks due to the higher limb velocities. Also the athlete is likely to not produce times close to personal best levels because of the freshness required to perform, and competition distances are sensitive to lack of arousal in practice.
Time and Split Analysis
The level of acceleration breakdown is based on the abilities of the coach and the equipment used. Timing gates offer instant feedback as well as long term data collection on how the sprinter created those performances in practice.
Meet analysis, a subject that will be discussed later, is often impossible to perform fully because of venue set-up and spectator and athlete interference. The simple question that coaches need to answer: is the athlete getting better year to year at the same points in time? With most programs not making dramatic changes each year, a coach can see development by just looking at total times during practice. It’s also good to video the change of times by looking at gross mechanical improvements with simple analysis. The amount of electronic timing and videoing during practice is based on the budget and time commitment, not necessarily the athlete’s ability.
An amazing training resource: Complete Speed Training Volume 2
Carl Valle is a USATF level II Sprints and Hurdles Coach and has worked with several olympians and coached athletes at all levels to dozens of school records and conference championships. He blogs for Elitetrack.com and optimizes technology for athlete performance.
Freelap is a fully-automated, wireless timing system that can accurately time fly-in sprints, splits, tempo runs, block starts, and more. Freelap is affordable for the individual athlete and expandable for team training.