Saturday, December 14, 2019

Rule-of-Thumb: 2 sec/mile/pound

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.

Saturday, November 16, 2019

Rule-of-Thumb: 100 Cal/mile

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.

Saturday, October 12, 2019

More Running Uphill

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.

Saturday, September 28, 2019

Running Uphill

Earlier, we talked about the power required for bicycling uphill.  Today we’ll talk about the same effects for running uphill.

Saturday, June 15, 2019

Thermal Conductivity

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.

Saturday, May 18, 2019

Specific Heat: cp and cv

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.

Saturday, April 20, 2019

Bicycling Downhill

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.