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.
The Urban Institute defined the middle class as adults with size-adjusted household incomes of between $30,000 and $100,000 for families of three. The Pew Research Center defines the middle-income category as including adults with family-of-three equivalent incomes between two-thirds and double the national median.