How much paddling effort is optimal for different parts of the race? Certainly very few if any athletes can go 100% effort for 2 continuous minutes without fatigue affecting performance, so for a 500 meter race, it behooves the athlete and coach to know how effort can best be used to pace the race in order to get the best time.
Our muscles contain several different types of fibers, each with their own attributes that allow us a range of force-exerting capabilities from holding a baby kitten to performing a heavy dead lift. Motor control is a complex system within the brain but outside the spinal cord, things get simpler. This is what we can focus on for the scope of this post. Motor neurons of different sizes connect like wires to muscle fibers, stimulating them to twitch and eventually reach sustained contraction, or tetanus, with enough action potentials/electrical signal.
We can group motor neurons into 2 main groups, large and small. Likewise muscle fibers can be grouped into 2 main types, Type I and Type IIa/IIx. Small motor neurons recruit Type I muscle fibers, which are slow to contract, produce low force, but are very fatigue resistant. Think of the muscles that operate your eyelids. Unless you’re the average college student, those things stay open most of the day and possibly through late nights in places your mother shouldn’t know about. Similar muscle fibers operate even when you are walking. Most healthy individuals can walk and talk with minimal fatigue.
Large motor neurons carry fast electrical signals to your so-called “fast-twitch” muscle fibers. These fibers take relatively more signal to contract, but once they do, they produce high amounts of force in a short period of time. They also fatigue quickly. Going from a walk to a sprint or performing a box jump will fire these Type II muscle fibers.
Muscle Fibers in Paddling
Paddling is a mix of muscle fiber utilization, as many daily activities are as well. The start of the race is strenuous because the boat is at a standstill and the water feels very thick/heavy. Taking hard strokes through this situation will favor the Type II fibers. As the boat reaches race pace and the speed plateaus, less emphasis on power per stroke (and thus less fatigue per stroke) can be applied to simply maintain race pace and hull speed vs accelerate the boat. Have you ever been on a boat where the crew hits an overrate and keeps it there? I have (a few times) and it doesn’t end well. Rating down and reducing power per stroke results in a lower reliance upon Type II fibers for paddling and less fatigue.
Some teams may call powers or some equivalent bump in effort to strategically stay ahead of other racers or simply to fight a gradual decline in hull speed. Again, taking harder or faster strokes will result in more Type II fibers being recruited, which will contribute to fatigue.
For the finish, is it better to pull a hard and fast acceleration or a gradual one? It depends. Highly trained athletes with good conditioning will have a better ability to recruit Type II fibers with less fatigue, but you can’t fight the physiology of trying hard. Fatigue will hit and sap the performance of any and all who exert 100% effort. No team wants to be slowing down by the end of the race, after all. In this sense, a hard and fast finish will mean an athlete can exert themselves for a shorter amount of time before bonking out.
Assuming that your boat is dead-even with the competition, travelling at the same speed, and the other crew maintains the same speed through the finish line, your crew will need to accelerate to pass the other boat. This is where a “finish” is useful in the most basic sense.
Acceleration requires the application of more force and power to the water. This power ramp can be applied gradually over a period of time or more aggressively in a compressed time frame. It obviously takes more energy to accelerate quickly and it is relatively more difficult to accelerate a moving boat than it is a stopped one (really!).
A crew that takes a more gradual approach to the finish may reduce the fatigue associated with accelerating the boat but will need to avoid making the finish so long that fatigue causes hull speed to drop before the finish line. The competition also poses a variable for when and how to run a finish. Calling the finish after that of other nearby crews potentially demands your boat to accelerate in a shorter amount of time to avoid being passed. Being “forced” to finish on account of another teams potentially better race piece may result in excess fatigue for your crew and decreased performance.
Most coaches recommend racing your own race, which has plenty of wisdom to it, however when up against close competition the ability to adapt on the fly is very useful when winning is all that matters.