Athletes typically ride about 7-8 stages, or until a break point in your blood lactate values has been distinguished. This break point area is known as your lactate threshold. You are said to have crossed lactate threshold when blood lactate concentration increases by at least 1 mmol/L in two consecutive stages.
Middle class. The middle class is a class of people in the middle of a social hierarchy. In Weberian socio-economic terms, the middle class is the broad group of people in contemporary society who fall socio-economically between the working class and upper class. The common measures of what constitutes middle class vary significantly among cultures. A sizable and healthy middle-class can be viewed as a characteristic of a healthy society.
Whether you're considered middle class most commonly depends on your income. But experts differ on how much you have to earn to fall into this camp. One of the narrowest definitions limits it to those who are literally in the middle fifth of the nation's income ladder. A wider characterization includes everyone but the poorest 20% and the wealthiest 20%.