What's one of the first things people do when evaluating a fishing rod? They typically check the action.
How to Check the Action of a Fishing Rod?
A simple way to check the action of the rod is to flex it against the ground or agains the ceiling. If it is not a pole, make sure the guides are facing upwards, then touch the end of your fishing rod on the ground (or ceiling) and apply some pressure. NOT TOO MUCH PREASURE. You will quickly be able to check the action of that fishing rod, without running the risk of breaking it.
A fishing rod with a fast tip means that the tip of the rod is flexible and the rest of the rod is stiff. Somewere from 1/4 to 1/3rd of your rod should be more flexible than the rest. The action of a rod is a rating, which describes the amount of curvature that occurs in the blank due to loading with weight. A rod's action determines its flexibility; it determines, in part, how much control you have over the fish. The faster the action, the more pressure you can put on the fish, the further towards the tip the rod bends. The slower the action, the further towards the middle of the rod and so on...
Softer action rods are more forgiving and have fewer tendencies to throw live bait from your hook. Fast-action and slow-action rods have their own unique characteristics. A fast-action rod is more sensitive compared to a slow-action Fishing Rod. For example with a fast-action rod you will be able to know if the lure reached the bottom by filling the lure's vibrations. On the other hand, a soft cast is possible using a slow-action rod, unlike a fast-action rod wherein it may break the bait off. If you are using a very light Fishing Line, it is advisable to use a slow-action rod when casting a considerable amount of bait or lure. Fast action rods put more force into your throw and give you longer casts.
Casting distance is one of the important considerations of rod action. The slower the action the better the rod will cast. Rods that have a slower action have a wider curve on their parabolic bend, and have stored more energy when casting. This is called "rod loading." In effect, the more the rod loads the more of the rod you use to cast. Fast action rods bend closer to the tip, using less of the rod to cast, they are great for most applications where a short to long casting distance is involved and single hooks are the rule, such as worm and jig fishing. Medium and medium-fast rods will usually provide a little more casting distance and still provide adequate hook setting power. These actions are often used for applications that involve treble hooks, such as crank baits and top water lures or other reaction baits such as spinner baits. Most bass rod actions are fast to very fast because this action generally provides better sensitivity and faster power for hook setting. By faster power we mean the rod 'shuts off' faster, or the bend ends higher on the blank, which means you don't have to move the rod as far on the hook set to get into the stiffer part of the blank.
You can think of action as how 'fast' it takes for the blank to return to 'rest' after being put under load. A fast blank is not going to flex very far from its resting state. Once the load is released it will not take long for the blank to return. Conversely, a 'slow' blank is going to flex in the top three-fourths of the blank. The range of motion is going to be much greater and will take longer for the blank to return to the at-rest state, thus, the term 'slow' is used to describe this characteristic.
Extra fast, fast, moderate and slow actions refer to flex and ultimately the relative time it takes for the rod to return to the at-rest position once released from under a load. By knowing and understanding the action of a blank, you can utilize that blank's properties to enhance a particular technique.
With equal weight a fast action rod will start to bend more toward the tip where as a slow action rod would tend to bend over the entire length of the shaft. A medium action rod would start to bend in the middle. The action is controlled by the taper of the rod itself. A fast or short taper would make a slower action rod and a slow or long taper would make for a faster action rod.