Myth #1 - Sending a horse around the round pen will decrease his adrenaline.

This truly depends on what speed you are "sending" the horse around the round pen. Most often "sending" a horse means at a canter or a lope. Tell me, how often do you see horses cantering or loping, especially at mock speed, and their adrenaline comes down? For some horses this can be true, but it requires the right circumstances for this to be true. For most horses, their adrenaline goes up. Especially Arabians and Thoroughbreds who are built for speed, they get more amped up the faster you make then go around the pen.

Myth #2 - Round penning a horse makes him easier to catch.

A study conducted by the Mammal Vocal Communication and Cognition unit of the University of Sussex in the United Kingdom has found young horses under the age of three are not able to understand when a human is paying attention to them.  Adult horses, however are able to use head movement and open or closed eyes to understand when a human is paying attention to them. The results of this study suggest the ability for horses to read and understand human body language is a skill that develops over time and with experience.

We've seen and/or heard what happens when a foal is raised by a human and doesn't understand horse body language...

When horses become upset or nervous they raise their heads.  You can teach your horse how to lower her head by creating a de-stress button on the ground and in the saddle.

First you will want to teach your horse how to give to pressure with a head drop exercise.  Stand on one side of your horse between her head and shoulders. Place one hand over the halter at the poll, and your other hand over the halter at the nose band. Apply steady downward pressure until your horse lowers her head, even if it's only half an inch. Your horse will learn the pressure goes away when she gives into the pressure by lowering her head. If she pushes back into your hands, continue to apply steady downward pressure until she relaxes the slightest bit. If your horse is really tall, try to keep your hands on your horse for as long as possible or stay with your hands raised towards her head until she relaxes and lowers her head the slightest bit. Repeat a couple of times, then do the same exercise on the other side of your horse.  Once your horse is really good with this exercise, to the point where you put your hands over the nose and poll and your horse lowers her head automatically (sometimes without even touching your horse), then you can advance the exercise to applying downward pressure from the lead rope.  Apply steady pressure until your horse lowers her head.  Repeat several times on each side of your horse.  This advanced exercise will need to be automatic as well before you can move on to the next stage.

Desensitize Your Horse - What Does that Really Mean?

If we look at the definition of desensitize and paraphrase, it means to make dull.  The dictionary defines the term as follows:

Definition of DESENSITIZE

1: to make (a sensitized or hypersensitive individual) insensitive or nonreactive to a sensitizing agent

2: to make emotionally insensitive or callous; specifically : to extinguish an emotional response (as of fear, anxiety, or guilt) to stimuli that formerly induced it

— de·sen·si·ti·za·tion noun

— de·sen·si·tiz·er noun

Medical Definition of DESENSITIZE

: to make less sensitive : reduce sensitivity in <desensitize a nerve with a local anesthetic>: as

a : to make (a sensitized or hypersensitive individual) insensitive or nonreactive to a sensitizing agent 

b : to extinguish an emotional response (as of fear, anxiety, or guilt) to stimuli which formerly induced it : make emotionally insensitive <evidence that violence on television desensitizes children to actual violence—Stephanie Harrington>

The question becomes, do we really want to make our horses insensitive, or emotionally insensitive?  Re-read the last line of part b of the medical definition inside the karats ( < > ).  That is a very powerful statement and I believe a reflection of what we see happening with violence in schools and around the world.  Do we want the same fate for our horses?