Strength training isn't rocket science, but there is some science involved. And for some of us, strength training is difficult to understand--all those exercises, sets, reps and workout routines can be confusing. Thankfully there's some basic strength-training advice that will make everything clear.

Everyone Sees Results at First

When you go from doing nothing to doing something, everything gets results. However, soon you'll see that results fade and progress stalls. You can't go to the gym and do the same workout day after day. What you do this month won't deliver the same results two months from now. With that in mind, create a plan for your workouts and track your progress using a training journal. This way you'll be able to vary the exercises and weights you are using.

Overload Your Muscles

Strength training uses resistance to break muscles down. Thankfully, our muscles respond to this training by growing back bigger and stronger. But, as we have already covered, there will come a time when the same-old-same won't cut it. That's because our muscles and body adapt to exercises and the weights that we use. To keep results coming, it's important to understand the principle of progressive overload.

Progressive overload says that we have to continually vary the amount and type of stress or resistance we're applying to our muscles. You could keep adding weight to the bar, but at some point you'll reach the maximum amount of weight you can lift. At that point, you'll have to come up with other ways to vary your workouts.

Mix it Up

This is your chance to get creative in the gym. Use different exercises. Increase the intensity by working faster to complete a workout. Or, try going all out against a running clock.

No matter how you do it, the goal is to change up your routine. This will help you make strength gains, and it will also help you prevent boredom. You're muscles can adapt to a training plan, but so can your mind. If you mix up your routine and keep things fresh, you can stay motivated towards achieving your goal.

Think Big

Big muscles, that is. Focus on using compound movements to train the body's biggest muscle groups--chest, back, legs and core.

Using free-weight exercises to train the big movers will allow you to get bigger strength gains and burn more calories in less time. Prioritize the squat, dead lift, bench press, overhead press and bent row in your training plan. Forgo the fancy exercise machines and stick to a barbell, kettlebells and dumbbells instead. Free weight tools like these will promote functional fitness and total body strength that can't be obtained using machines.

Work Hard, But Not Too Hard

You should be sore after workouts, but you should never be in pain. Over training is a real thing that happens when you exercise too often, too intensely or use too much weight. Don't overdo it. Instead, select a weight that you can manage for 10 to 15 repetitions. If you can do more than 15 repetitions, it's time to add some weight. But, if you're struggling to complete 10 repetitions, it's time to back off the weight. If you keep training, you'll continue to make progress and will be able to increase the weight in no time. Resist the urge to do too much too soon.