The phrase "peak levels" refers to the highest or maximum point that something can reach. It indicates the point where something is at its greatest or most intense state. Full definition
The number you should pay attention to here is the number for continuous or sustained power, rather than the number of peak levels of power. (thatvideogameblog.com)
Wouldn't you love to feel even more alert, more awake and performing at peak levels after lunch? (blog.fitplanapp.com)
The key is to find the right amount of rest so that we reach peak levels of energy, mood, and performance at the proper times. (mindbodygreen.com)