Day 2: From muscles to lungs

The control

First we will bubble our breath into the indicator after resting. Carbon dioxide in our breath is acidic so the indicator will turn red over time.

The experiment

Then we will repeat in the second indicator mixture after exercise. By comparing how long the control and the experiment take to turn pink, we will infer whether our muscle cells burn more sugar during exercise or not.

The details 

Fill two glasses or white cups with one-third indicator-water mix.

Sit still for half an hour (do some reading, notes, drawing, or classwork for another class).

Follow the method shown in the Breath Experiment Clip video.

Then take two deep breaths in and out first. Using a straw and a seconds timer, breathe in, lower the straw into the liquid. Time how long it takes to breathe out into the indicator and turn the first glass pink. Write down the time in seconds. Keep the glass as a match.

Do a lot of jumping jacks! As many as you can!

Immediately after you stop, breathe into the second glass using a straw time how long it takes to turn the second glass as pink as the first one. Write down the time in seconds.