Maximal strength is related to the peak force-generating capacity and rate of force development. Many confuse it as power, but it is not quite the same. Any sport that requires power (including fighting) can benefit from maximal strength training.
Both powerlifters and Olympic weightlifters train in order to maximize their maximal strength, the difference lies in the movements their competitions demand. Powerlifters compete with very simple movements that can be executed with low velocity, Olympic lifts are more complex and require high velocity.
A muscle strengthens when trained near its current maximal force-generating capacity (McArdle et al., 2010).
This statement expresses the high degree of certainty that we have that loads must be high for maximal strength adaptations to occur. Load is the most important variable in maximal strength training: a load close to the 1-RM is essential to trigger maximal strength gains.
Maximal strength is not only the result of muscular adaptations, but also of neural adaptations (McArdle et al., 2010). Exercise scientists often face the problem that test subjects are quick at learning a new movement, and thus quick at becoming better at performing the test they're subject to. This is a problem because it is difficult to separate this learning process from the training outcome, in order to quantify the effectiveness of a training intervention and not the ability of their subjects to learn and become better at the test.
Measuring maximal strength is usually done with a 1-RM test of one or more lifts. Therefore, becoming better at performing the test is very important.
These neural adaptations are strengthened by repetitions and weakened by time (Schmidt & Lee, 2011). In other words, strengthened by high volume and weakened by low frequency. For maximal strength training, volume and frequency are important, but not as important as load. Since load must be high, then volume and frequency must be relatively low.