Differences Between Bulky Muscles and Toned Muscles

Some people want to add size to their muscles, while other people just want to look more defined. This is the difference between a bulky body and a toned body. Although certain factors related to lean muscle development are beyond your control, you can use resistance training strategies to make your muscles appear larger or just more toned.

Toning actually has more to do with your body fat level than the muscle itself. Many women desire to have toned, lean muscles that are normal in size or slightly developed and visible underneath the skin — whether a little or a lot. Because everyone has some lean muscle, anyone can get toned just by losing body fat.

People who want to be toned, but not muscular or bulky, don't need to do any specialized type of training (although they still need to strength train). They also need to keep their caloric intake controlled — lowering the calorie intake slightly below daily calorie needs to burn the fat covering their muscles.

Muscle bulk refers to the size of the muscle. If you want to picture bulky muscles, just think of the Incredible Hulk — or maybe just some of the guys at your gym. Generally, they are the ones lifting heavy weights and sipping on protein shakes during their workouts.

Bulking up doesn't typically involve body fat — it has entirely to do with building muscle mass. Bodybuilders go through a bulking phase in which their main goal is to increase the size of their muscles. In the cutting phase, they lose fat to make their muscles look more defined.

Building a bulky body depends first and foremost on your body type. After that, manipulating certain training strategies can determine how much mass you can build.

People come in all shapes and sizes, primarily determined by their genetics. These shapes and sizes are known as body types and predict how much muscle an individual can build and how easily. There are three main body types:

Ectomorphs are naturally skinny. They have slight frames and small muscles. They also have fast metabolisms and tend to have trouble gaining weight — both fat and muscle. In the gym, these guys are often referred to as "hardgainers." It's easy for them to looked toned, but very difficult for them to bulk up.

Endomorphs are the exact opposite. They have large frames and put on muscle easily. But they also have slower metabolisms and can easily put on fat. Bulking is no problem for them, but looking toned is challenging.

Mesomorphs are in the middle. They have the "ideal" athletic body type, with medium-sized frames, broad shoulders and proportionately small waists. Think Superman. Mesomorphs put on muscle easily and lose fat easily and can bulk up if they want to — and look toned.

Several factors play a role in muscle hypertrophy, or growth, all of which can be manipulated to increase the effectiveness of your program. These include:

• Load — how much weight is lifted
• Volume — how many sets and reps you do each week
• Frequency — how many times a muscle group is worked each week
• Rest — time required for recovery between sets
• Recovery — time required for muscle repair between workouts

In addition, protein intake, sleep amount and quality, and stress levels also affect muscle gain.

Read more: How to Build Dense Muscle

As far as what you do in the gym, the longstanding recommendation for hypertrophy from organizations like the National Academy of Sports Medicine (NASM) is to lift moderate weight for moderate reps with moderate volume and moderate rest between sets.

For example, for a chest press, you would lift 75 percent of your one-rep max (1RM) for three to five sets of six to 12 reps with one to two minutes of rest in between sets. A two-day split routine — working chest, shoulders and triceps on one day and back, biceps and legs on another day — is the recommended frequency.

Not much of the recent scientific research corroborates NASM's recommendations, however. For example, a small study published in October 2015 in the Journal of Strength and Conditioning Research found that it didn't matter whether participants lifted moderate weights for moderate reps (eight to 12) or lighter weights for higher reps (25 to 35).

Both groups performed three sets of seven exercises to volitional failure three days per week for eight weeks. At the end of the trial, both groups gained significant muscle mass, and there was no difference in the amount gained.

In another small study, in the Journal of Strength and Conditioning Research in July 2016, muscle growth was enhanced by longer interset rest periods. Two groups of trained men performed the same workout, but one group rested one minute between sets and the other group rested three minutes. At the end of the eight-week study, muscle growth was significantly greater in the group that rested for three minutes.

Additionally, while the NASM recommends six to 10 sets per body part per week, this may not be nearly enough to encourage optimal muscle growth. A June 2017 systematic review and meta-analysis in the Journal of Sports Science determined that there is a dose-response relationship between hypertrophy and weekly training volume.

In the studies they reviewed, each additional set performed corresponded to a 0.37 percent gain in muscle size. A May 2015 study in the Journal of Strength and Conditioning Research found that a group of 48 participants who performed 15 sets of each exercise each week achieved much greater muscle growth than those who performed three or nine sets weekly.

Read more: The Best Exercises for Every Major Muscle

Even if your goal is toning, it's still important to strength train. When you're stronger, you can complete everyday activities with more ease. And resistance training builds bone density, leading to a lower risk of osteoporosis and arthritis. It also improves blood glucose control, sleep quality and mental well-being.

When your goal is building functional strength without getting a bulky body, it makes sense to not follow the strategies discussed for building muscle. Keep your weekly volume low, performing one to three sets of exercises and resting for one minute or less between sets.

Your diet plays a bigger role in looking toned. Cut out sugary, fried and fast foods, and eat more fiber-rich vegetables, whole grains and lean protein from chicken, fish, eggs and beans. These foods will help you control your appetite and calorie intake to lose fat, while also providing the nutrients you need for energy and overall health.