During those days when your to-do list seems to lengthen regardless of your best efforts to check off your chores, it probably feels like you're sprinting from task to task, dusk until dawn. When your head finally hits the pillow, your legs are likely fatigued from all the day’s running around. Sprinters can certainly relate to the feeling of fatigue that makes you grateful for your fluffy feather-filled friend. Despite the shorter course lengths that sprinters travel, they experience fatigue just like longer distance marathon runners. The culprits for a sprinter's fatigue, however, are sometimes different than those of long-distance runners and long-list warriors.
Muscle tiredness and exhaustion is the most common form of fatigue. Think of how your body feels after a powerful run or workout at the gym. It's this weighted weariness that leads to a diminished drive in your muscles and an increased longing for a comfortable chair and cup of tea. Although physical fatigue of the muscles influences all runners’ performance, sprinters may be affected more often because they tend to have more fast-twitch muscle fibers. These fibers produce better bursts of speed, but they also tire more quickly.
Your central nervous system is responsible for carrying messages to and from your brain. It basically tells your muscles what to do. Ultimately, however, the message it delivers comes from your thoughts. When you tell your feet to relax into a warm, bubbly bath at the nail salon, they do, and when you tell them to knock out a two-mile run, they should respond to that as well. Similarly, when a sprinter's muscles become too tired to power through a race, her mental messages can communicate a different message to her muscles, enabling her to dash to the finish line. Conversely, when a sprinter experiences mental fatigue, she can send fatigue-filled messages to her muscles and cause them to perform poorly and slowly.
Sprinting requires the highest rate of energy supply. Therefore, sprinters' bodies need to be efficient in converting chemical energy into mechanical energy. Basically, their morning granola needs to quickly convert into their mid-morning fartlek, or speed work. When their bodies experience metabolic fatigue, the speed of sprinters' muscle contractions is lessened, thus hindering their performance.
Energy depletion typically occurs with longer running distances and longer days of work. When you use all of your stored energy, you will experience fatigue. Though it is possible for a sprinter to experience fatigue due to energy depletion, it doesn't happen often. Runners typically store enough energy to fuel them through two hours of running at an average pace. Whether you're a sprinter, a long-distance runner or someone who simply does her fair share of running around, taking a break to refuel can help you complete your day’s race more efficiently.
Mary Marcia Brown has worked in the health and fitness industry for more than 15 years. A writer and runner with road race directorship experience, Brown has been published in "Running Journal," "Florida Running & Triathlon" and "Outreach NC."