Fixed Weight Dumbbells
Dumbbells are available in many shapes, sizes, and weights. Considered to be superior to their barbell counter parts, the usage of dumbbells for exercises often employs the use of various stabilizer muscles to control the individual weights as opposed to a singular bar.
The most common form of dumbbell is the fixed weight version. Fixed weight dumbbells consist of a solid weight that cannot be altered. Variations of the fixed weight dumbbell include: all metal, metal wrapped in rubber (for added hand comfort), metal wrapped in rubber on the outside of the weight (to reduce floor damage when releasing the weights), and plastic dumbbells with water or sand inside. Fixed weight dumbbells are often found in two designs: hexagonal edges and rounded edges. There are hybrids of these designs with rounded edges but many small, straight edges to keep the weight from rolling.
Adjustable Weight Dumbbells
A somewhat less common dumbbell is the adjustable weight dumbbell. Generally made from metal like the fixed weight version, the adjustable weight allows one to add additional weight plates by unscrewing an end cap or adjusting a clamp to secure the plates. These are more commonly found in home gyms because it is much less expensive than buying fixed weight dumbbells in a large variety of weight denominations. In regards to gyms, these are rarely found because it is extremely difficult to keep all the plates and securing devices available and organized.
A type of dumbbell that is becoming quite popular in home gyms is the selectable weight dumbbell. These dumbbells often include stands made specifically to hold and allow for selection of the weight discs that attach to the dumbbells. Add-on kits are usually available if the standard maximum weight load is not enough to achieve optimal results.
Working with dumbbells allows one to be a bit more careless than a barbell. All too often it seems that individuals using dumbbells will reach the point of failure and toss the dumbbells to the ground. This is highly dangerous to the one lifting as well as any surrounding individuals. With dumbbells designed the way they are, they have been known to bounce uncontrollably and cause serious injury. One should always attempt to slowly the lower the dumbbell down as close to the ground as possible before releasing one's grip.
Throwing of the dumbbells also degrades the quality of the dumbbell. When the dumbbell impacts on the outer portion, it may bend the handle of the dumbbell, causing the grip to become warped and curved. Whether it is made from metal, plastic, or a combination of both, the outer portion can also suffer chips or dents as a result of throwing the weight down.