My 8th graders are about to learn what the immune system is and what it does. Here's a video to use if you want to help teach the inhume system.
The F.I.T.T. principle can be hard to grasp for a 4th grader but videos and games can help to understand each component. This article will give you a couple of ideas on how to teach the F.I.T.T. principles of training.
F.I.T.T. = Frequency, Intensity, Time, Type
I usually teach each concept one at a time. Adding another one either later in the lesson or the next day until the students seem to have a concrete understanding of each. Once they understand each one individually we work on putting them together.
Strategy #1) F.I.T.T. Tag
I choose 4 students to be the taggers. Each student represents one of the F.I.T.T. principles. If a student gets tagged they have to ask the person what they are representing and find that poster around the gym. Once they find the poster they read information about that principle. I usually have an example on the poster so the students can perform an activity. I usually start with only 2 concepts, play again with the other 2, then play again with all 4.
Strategy #2) Scavenger Hunt
Scatter the principles all over the gym, the school, the field, ext. Have the students go through an obstacle course and try to find all the principles. Once they find all the principles they have to go back through to find the definitions. The bigger the obstacle course the better. Think "Tough Mudder" or "Par-core".
Strategy #3) Fishing
Yeah, you read that right. I do a kayaking/fly fishing unit in my gym every year. The students love this. We use the scooters as kayaks, random things for paddles, cones for rocks, noodles for logs, jump ropes for snakes, and ribbon sticks for fly rods. The students kayak through the river to the lake. In the lake they will try to "catch" a fish. They do this by using their ribbon stick and trying to touch a fish. The fish are paper cut outs. One each fish is one of the F.I.T.T. principles. Their goal is to catch all 4 but there is a 1 fish limit every time they visit the lake. This means they have to go through the course 4 times. Once they have all 4 they have to match the fish with the definition.
And that's a wrap.
As always if you have any other suggestions feel free to post them in the comments.