Size training and strength training! Does size follow strength? The human body is a very complex machine. It can specifically adapt to different types of training. For example, fast-twitch muscle fibers, those that bodybuilders are most concerned with, can be divided into two types with specific training protocols.

Fast Twitch Fibers

Let’s look at each and find out how they relate to size training and strength training.

1) FOG (fast, oxidative, glycolytic) – This type has the ability to utilize oxygen at a more efficient rate. This enables it to contract quickly and be somewhat fatigue resistant. It also has the greatest capacity for size increases.

2) FG (fast, glycolytic) – This type is better suited for pure power events such as the shot put and limit attempts in powerlifting.

It has been conclusively demonstrated that fast-twitch muscle has the ability to transform from FOG to FG with power training. The opposite is true with bodybuilding training.

Fast-Twitch Comparison

The training methods for strength and muscle mass are similar. They must both include resistance work at an elevated intensity level. However, FG, or strength, fibers require a significantly higher intensity. You get the best twitch response from strength oriented fibers. This is true when you emphasize acceleration in the concentric, or positive, portion of your repetitions. It also appears that you get a higher twitch response when you use compound movements. This is exercises that involve two or more muscles in conjunction, such as squats. The repetition range for FG-fiber training is one to six. The fewer the repetitions, the more FG isolation you get.

Size Training And Strength Training – What Fibers Do You Want To Emphasize?

If you’re a bodybuilder, you want to stress primarily the FOG fibers. To do this, you must also train hard, but at a paced high intensity. FOG fibers, due to their somewhat fatigue-resistant qualities, need more repetitions. Eight to 15 appears to be the optimal number for building muscle mass.

Size Training – Time Under Tension

It’s the time the muscle spends in maximal exercise that’s the true determinant of the primary fiber type. For optimal strength development it appears that the exercise should be around 90 percent anaerobic. Or, no more than a total of 15 seconds of actual performance time during any work set. For muscle mass the optimal energy production is 66 to 85 percent. That’s between 25 and 75 seconds of performance time.

For example: Perform a set of only six repetitions. Include an isometric contraction at the top of each rep. As well, emphasize the negative, or eccentric, phase of each rep. This combination could triple the tension time on the muscle. That makes it an FOG-dominant, or bodybuilding, exercise.

On the other hand, perform those six repetitions with very short pauses between them. This allows the muscle to recover somewhat. You aren’t keeping constant tension on it. You are focusing on acceleration. This will stress the FG fibers. That makes it more of a strength-building set. So, muscle mass means total tension time at a maximal paced intensity. This is instead of counting repetitions. Remember, each set should last 25 to 75 seconds.

Strength trainers should concentrate on quick, explosive sets. Use a short rest/pause between repetitions. Your work sets can be performed for submaximum repetitions. Use short rest periods between sets. This is one of the basic concepts of the Bulgarian training style. It specifically targets the FG, or strength, fibers.

Size Training – Recruitment Overlap

In simplest terms, to target FG, or strength, fibers, you perform your repetitions in a certain way. Focus on acceleration with the set lasting about 15 seconds. To target EGG, or muscle mass, fibers, focus on keeping tension on the working muscles for 25 to 75 seconds. Work until fatigue sets in.

Keep in mind that there’s significant overlap between the two fiber types. For example, some FG-specific training aids in mass development. This is due to the increase in strength. Also the increase in recruitment of muscle fibers. Also, some FOG-specific training aids in strength development. This is based on the increase in muscle size and endurance.

FG (Strength/Power)

• Emphasize acceleration
• Perform each repetition like individual singles, with a rest/pause between repetitions
• Train with maximum intensity
• Do six or fewer reps per set
• Maintain a core time per set: 15 seconds (this is work time, not rest time)
• Use a heavier average resistance

FOG (Muscle Mass)

• Emphasize sets to failure
• Use more continuous-tension time for each individual repetition and between repetitions.
• Train with paced intensity
• Do eight to 15 reps per set
• Maintain a core time per set: 25 to 75 seconds (this is work time, not rest time)
• Use a lighter average resistance