These strength training guidelines will help you develop an effective strength training routine.
Frequency
There's no single ideal training frequency. How many days per week you lift weights depends on factors such as your training goals, your level of training experience, your recovery ability, and how many different muscle groups you train each workout.
Rest days are just as important as training days because muscles don't grow during training, they grow after training. Weight lifting causes microscopic tears in muscles, and rest days allow muscles to repair themselves, grow and get stronger. A muscle needs at least 48 hours of rest to recover from a weight lifting workout, so never train the same muscle group two days in a row.
Duration
A weight lifting workout should last no more than 60 minutes. After 60 minutes, your body begins to stop producing the muscle building/fat burning hormones testosterone and human growth hormone and starts producing the hormone cortisol, which can tear down muscle tissue and contribute to fat storage.
Repetitions and Sets
Performing 1-5 reps per set primarily builds strength and power. Performing 8-12 reps per set is best for overall muscle development. Performing more than 20 reps per set primarily builds muscular endurance.
Fitness experts have varying opinions on how many sets should be performed for each exercise during a workout, but many recommend performing three sets (not including warm up sets) per exercise. Use this as a general guideline and then adjust as needed based on factors such as what body part you're training, what exercises you're performing, and what your training goals are.
Rest Between Sets
As a general guideline, the rest between sets should be 30-90 seconds. The rest time will vary depending on factors such as what body part you're training, what exercises you're performing, and what your training goals are.
Number of Exercises
As a general guideline, beginning weight lifters should perform one exercise per body part, intermediate weight lifters should perform two exercises per body part, and advanced weight lifters should perform three exercises per body part. Adjust this guideline as needed based on factors such as what body part you're training, what exercises you're performing, and what your training goals are.
Free Weights vs. Weight Machines
There's long been debate about which is better, free weights or weight machines. Both have their pros and cons, but the bottom line is that both will build muscle and increase strength. If you have access to both free weights and weight machines, use both in your workout routine. You'll find that some of your body parts respond better to free weight exercises while other body parts respond better to machine exercises. Also, the combination of free weights and weight machines will add more variety to your workout routine.
Form and Technique
Using good form and technique is one of the most disregarded strength training guidelines. Many people perform their reps at a fast speed, swinging the weight up and down. This is often because they're using a weight that's too heavy for them and they have to use momentum to lift the weight. Use muscle power, not momentum, when lifting weights. Don't heave, swing or bounce the weight. Lift and lower the weight in a controlled manner. Concentrate on feeling the muscle that you're working.
Warming Up
Warming up is another one of the strength training guidelines that's frequently ignored. Warming up is important because it stimulates blood flow to your muscles, it increases your joint flexibility and range of motion, it gets you mentally prepared for your workout, and it helps prevent injury. Warm up by doing one or more light sets of each weight lifting exercise before using heavier weights.
Changing Workout Routines
You should change your workout routine once you stop seeing noticeable results on a consistent basis. You don't necessarily have to change your entire workout routine, but some new stimulus must be put into the routine or you're not likely to make further progress. Changes also keep things interesting.
In conclusion, these strength training guidelines provide a good starting point for developing an effective strength training routine. For more information on developing an effective strength training routine, check out Bodybuilding Revealed. It's an excellent program and I highly recommend it.