Last time we looked at a rule-of-thumb for energy used in running. Today we’ll look at
another rule-of -thumb for the effect of runner weight on pace. There is a fair amount of wild speculation, rigorous study, anecdotal experience, and intuitive assertion about this topic, but a lot of conclusions seem to center around a time penalty of 1-4 seconds per mile per pound of body weight. We’ll look at that range in terms of energy use.
In the last two posts, here and here, we looked at the relationships between grade, power
expenditure, and pace for running. In those posts, we had to make an assumption about a “base” power use which we defined as the power required to run at a steady pace on flat ground. Since we were interested mostly in the additional power associated with running up a grade, and since that “base” power is so complicated to estimate for any particular individual, we simply invoked a common rule-of-thumb and used 100 Cal per mile as our base power. Today, we’ll explore that rule-of-thumb in a little more depth.
Last post we looked at the energy cost of running uphill at a certain pace. This time we’ll flip that around and look at the uphill pace that could be maintained for a fixed amount of power. We’ll also look at the total power required as a function of pace, grade, and weight.
Earlier, we talked about the power required for bicycling uphill. Today we’ll talk about the same effects for running uphill.
In keeping with the theme of material properties from the last post, today we’ll talk about thermal conductivity which is a material property that relates to the conduction of heat.
Earlier, we looked at the specific heat ratio, and we also looked at the variation in specific heat with temperature here and here. Today we’ll look in a little more detail at the properties constant volume and constant pressure specific heat.
We’ve been talking here and here about the effects of weight, speed, and grade on climbing hills on a bicycle. Now, let’s reverse direction and think about coasting down a hill.
Last time we looked at how weight and speed and grade affect the power requirement for a bicyclist climbing a hill. Today, we’ll reverse the question and assume that the cyclist has a fixed amount of power to deliver. How will that affect climbing speed?
Not long ago I was huffing and puffing on my bicycle up a very steep hill and another cyclist blew by me with apparently little effort. Now, in addition to looking younger, stronger, and having a better bicycle, he appeared to be carrying significantly less excess, ahem, baggage. So I got to wondering how much difference one’s weight (or to be charitable, a loaded backpack) makes when ascending a hill on a bicycle.
