# Physical attributes as a function of age

My workerclass has physical attributes such as physical_fitness and sexual_fitness which are intended to be functions of their age (the attribute is, unsurprisingly, called age). When the class is initialized, the initial values of XYZ_fitness are computed by a randomized normal distribution.

In each game tick, worker's grow a year older. I want to appreciate/depreciate the values of their physical attributes such that, for example, they increase until they are at their maximum value around age 35, and decline with age after that. What is an efficient way of defining this function?

Would this involve something like running their age through a quadratic function with its maxima at the age value 35? I'm sure there's some elegant math/statistics here that's escaping me.