Weight training is based on training principles beginning with the overload principle. Training gains occur when your muscles work to overcome a workload that is greater than normal. Weight machines and free weights provide this overload with different types of resistance; constant and variable. Weight training, or resistance training programs, are designed to increase muscular strength and endurance, the ability of your muscles to exert force repeatedly.
Structure
Your muscles are made up of muscle fibers that contract in order to exert force to overcome resistance. When the resistance is less than the maximal amount you can lift, you recruit a percentage of the fibers. With repeated movements, or repetitions, more and more fibers are recruited. Weight training exercises are designed to reach 100 percent of muscle fiber recruitment with every set or groups of repetitions, according to the Body Recomposition website.
Equipment
With weight training, resistance is provided in the form of free weights, machines, resistance bands and body weight. All training is considered dynamic, or with movement. The types of resistance may be constant or variable. Constant resistance has a fixed weight or amount of resistance throughout the movement. Examples of dynamic, constant resistance are free weights and barbells. A 10 pound dumbbell provides 10 pounds of resistance throughout the movement. Dynamic, variable resistance machines work with cams, pulleys and levers to vary the weight during the range of movement. Weight machines with grips or handles attached to pulleys that are attached to weight stacks are examples of dynamic, variable resistance machines.
Effects
Your muscles vary in their strength capacity when lifting a weight through a full range of motion. You are stronger at the beginning and the end of the movement. The middle part of the movement, where the sticking point occurs, is where your muscle is at its weakest. When using constant resistance, you tend to use lower weights to make it past the sticking point. When using variable resistance, the resistance is higher where your muscles are stronger, and lighter where your muscles are weaker. This allows you to work with a weight that matches your strength levels throughout the movement, says the American Council on Exercise "Personal Trainer Manual."
Benefits
Benefits of weight training include increased muscle strength and size, along with increased bone mass and connective tissue strength. All types of resistance training provide benefits. When comparing variable resistance with constant resistance, many individuals prefer the variable resistance due to the ease of use and ability to monitor increases in strength. Disadvantages of variable resistance machines include expense and limitations of the machine. Many different exercises can be performed with dumbbells and they can be purchased for home use. Variable resistance machines are expensive with a limit of one exercise per machine.
Considerations
First time exercisers should consult a physician prior to starting an exercise program.
References
- "Keep Moving: Fitness Through Aerobics and Step:; Esther Pryor & Minda Goodman Kraines; 2000
- Body Recomposition: Reps Per Set for Optimal Growth
- "Personal Trainer Manual"; American Council on Exercise; 1991
- CEC Article: Physiological Response to Dynamic Exercise
- Muscular Strength
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