Yes you do. Plus, a number of weight training studies on athletes illustrates this important, yet often overlooked aspect. To make quality gains in strength, you’ve got to lift loads that consistently reside in the lower RMs (rep maximums).
For example, the competitive season is a difficult time for most athletes to make strength gains. Studies consistently show that barbell squat and bench press strength improves when the athlete still trains with high loads and lower reps ranges (above 80% of the 1RM) during this time.
Quite often, when athletes choose to use lighter loads (below 80% of their 1RM) strength gains are tough to achieve. By choosing to work in the 4 to 6 max-rep range you can be assured of utilizing a training intensity that will optimize strength development. That old cliché “you have to lift big to get big” seems to be substantiated by modern strength training research.
Source: The Journal of Strength and Conditioning Research