Sprinting is the pinnacle of speed movements that a human can perform under their own power.
Usually in individual sports the one who can sprint the fastest wins, depending on the competition.
In sustained team sporting events the athletes that can move the fastest to achieve the sport objective on a repeated basis usually wins for their team. This is the concept of repeat sprint ability.
Repeat sprint ability (RSA) describes the ability of an athlete to recover and maintain maximal effort during subsequent sprints (1). The two main keys to that sentence are recovery and maximal effort.
Maximal effort is an easy concept to understand. It is the highest amount of output at which an athlete can perform and in this case it is referencing sprinting speed. Maintaining higher sprint speeds in subsequent sprints equals a higher RSA.
When discussing recovery there are more factors to consider, such as the athlete's heart rate drop, their nervous system and the efficiency of their energy systems.
Heart rate drop is the difference between the highest beats per minute (BPM) the athlete generates and the lowest BPM they can achieve during rest. In most cases the higher the drop during rest, in between maximal efforts, the more likely the athlete can prevent fatigue to be able repeat the effort.
The nervous system recovery is dependent on the body's supply of neurotransmitters. A large variety of neurotransmitters are present and are generally responsible for sending signals from our brain to the muscles. When we work through our supply of these transmitters the signal becomes weaker, until we produce more. The athlete that is more efficient with this supply will be able to repeat the effort more consistently.
The energy systems are heavily dependent on disposable fuel present in our bodies and in our bodies our main fuel is known as ATP (adenosine triphosphate). We produce ATP through multiple systems in which we transform our food into usable energy. During the action of sprinting we also use a fuel called PCr (Phosphocreatine). Both of these fuels are constantly being used and produced on a continuous cycle. If we have an increased demand we will have an increased production, assuming we have adequate food supply. Again when looking at this aspect of recovery the athlete that is more efficient with their supply and production of PCr and ATP will be able to repeat the effort more consistently.
This is also why supplements such as creatine are such a great performance booster. Having more creatine available in the body to produce this PCr will increase the efficiency of this system.
RSA is a trainable skill, meaning an athlete can improve their RSA. It should be trained in athletes to improve their overall performance. Breaking it down into the separate qualities is how you will successfully train RSA as a whole. However to train this properly it should be sport specific because not all sports have the same demands when considering speed, sprint time and recovery time.
Sprint time and recovery in between sprints varies greatly depending on the sport in question. For example a typical football play will last anywhere from 4-7 seconds of full out effort with a rest of 30-45 seconds in between plays. Whereas in a hockey game one single shift, averaging around 45 seconds, could consist of multiple maximum efforts back to back between 3-5 seconds with a sub-maximal effort covering the remainder of that shift, not allowing for adequate recovery until they are off the ice. So you can see the demands for these sports are very different in the amount of output and recovery they require.
Training for sprinting speed, no matter the sport, can be improved through the same means: resistance training and maximal effort sprints. To sprint faster you need to be strong and you need to sprint more! Adjusting the resistance training program and sprint time would be the factors to consider when training for different sports.
To train your recovery is a different story but can also be broken down into separate qualities that athletes can improve upon. Training heart rate recovery is to train the heart. Improving the number of beats dropped in between maximal efforts can be improved two ways, by increasing the cardiac output of the heart and by improving the efficiency at anaerobic threshold.
Cardiac output is defined as the amount of blood the heart can pump out each minute. Improving cardiac output can be achieved through long duration low heart rate cardio. Anywhere between 120 -150 bpm for a duration of longer than 45 minutes.
The anaerobic threshold is a particular heart rate zone in which the athlete switches from using oxygen to not using oxygen. This state can’t be maintained for long and severely decreases performance and recovery. Improving the anaerobic threshold can be achieved through shorter bouts of high intensity conditioning, ensuring the heart rate does not surpass the threshold, with recovery in between. Determining the anaerobic threshold can be done through various exercise tests.
Image - Example of an athlete's anaerobic threshold.
The efficiency of the nervous system and also of the multiple energy systems will improve and adapt as you train the above. The more you sprint, the more your nervous system will become accustomed to maintaining maximal effort; as is the case with the energy systems.
Repeat sprint ability is a major factor in an athlete's success. Some must train very hard to achieve an improvement in this quality while others fall upon it naturally just by playing sports. Nevertheless it should be considered when preparing for any team sport.
1)Turner, Anthony N. MSc, CSCS*D1; Stewart, Perry F. MSc, CSCS, Repeat Sprint Ability, Strength and Conditioning Journal: February 2013 - Volume 35 - Issue 1 - p 37-41
Img - https://strengthmatters.com/what-is-the-anaerobic-threshold-a-beginners-guide/