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EMG Electromyography

EMG Activation (Electromyography)

What's all the fuss about?

In the new age of bodybuilding, there’s a plethora of individuals who love to discuss optimal training. One way they like to discuss it, is by picking apart EMG Activation or Electromyography of a given exercise.

Now you’re probably reading this article because you want to know what the hell that is and why people keep talking about it. So read on, we’ve got you covered. 

EMG (Electromyography) in Bodybuilding: Enhancing Exercise Selection for Optimal Muscle Activation

In the world of bodybuilding, achieving optimal muscle activation during exercises is essential for effective muscle development. One tool that has become increasingly valuable for exercise selection and performance analysis is Electromyography (EMG). EMG is a non-invasive technique that measures the electrical activity produced by muscles during contraction. In this article, we will delve into what EMG is, how it works, and its practical applications in bodybuilding to help athletes and fitness enthusiasts make informed exercise choices for maximizing muscle growth and performance.

What is EMG?

Electromyography is a diagnostic and research tool that provides insights into the neuromuscular system’s functioning. It involves the use of electrodes to detect and record the electrical signals generated by muscles when they contract. These electrical signals, known as action potentials, provide valuable data on the level of muscle activation, recruitment patterns, and muscle fatigue.

How Does it Work?

During muscle contraction, motor neurons send electrical impulses to the muscle fibers, triggering them to contract. EMG electrodes placed on the skin or inserted directly into the muscle tissue can detect these electrical signals. When the muscle activates, the EMG device records the electrical activity, representing it in graphical form or numerical values.

EMG Activation
Why does it matter in exercise selection?

One of the most practical applications of EMG in bodybuilding is exercise selection. By assessing muscle activation levels, bodybuilders can identify exercises that effectively target specific muscle groups. This knowledge allows them to design training programs that maximize muscle hypertrophy and strength gains.

1. Muscle Activation Patterns: EMG provides valuable data on the sequence and timing of muscle activation during different exercises. For example, a bodybuilder can compare the muscle activation patterns of a barbell bench press and a dumbbell bench press to determine which exercise recruits more muscle fibers in the chest, shoulders, and triceps.

2. Identifying Muscle Imbalances: EMG can reveal muscle imbalances and weaknesses within muscle groups. This information helps bodybuilders design corrective exercises to address these imbalances, reducing the risk of injuries and enhancing overall muscle development.

3. Exercise Modification: EMG data can guide exercise modifications to target specific muscle groups more effectively. By adjusting variables such as grip width, foot stance, or range of motion, bodybuilders can optimize muscle activation during exercises.

4. Muscle-Focused Training: EMG analysis enables bodybuilders to perform muscle-focused training, emphasizing certain muscles over others during compound exercises. For instance, adjusting hand placement on a pull-up bar can shift the emphasis from the biceps to the lats.

Example of EMG activation for a barbell bench press

Several studies have investigated EMG activation across different bench press grips. One of the seminal studies in this area was conducted by Lehman et al. in 2005, titled “Electromyographic Analysis of the Bench Press at Shoulder and Elbow Joints.” This study compared the EMG activation of the pectoralis major, anterior deltoid, and triceps muscles during three different bench press grips: wide grip, shoulder-width grip, and narrow grip.

According to Lehman et al. (2005), the results showed the following muscle activation patterns:

  1. Pectoralis Major: The wide grip bench press elicited higher EMG activity in the pectoralis major muscles compared to the narrow grip bench press. The shoulder-width grip bench press showed intermediate activation levels.

  2. Anterior Deltoid: The narrow grip bench press resulted in higher EMG activity in the anterior deltoid muscles compared to the wide grip bench press. The shoulder-width grip bench press showed intermediate activation levels.

  3. Triceps Brachii: The narrow grip bench press also demonstrated higher EMG activity in the triceps brachii muscles compared to the wide grip bench press. The shoulder-width grip bench press showed intermediate activation levels.

These findings suggest that different bench press grip widths can emphasize specific muscle groups. A wider grip places more emphasis on the pectoralis major, while a narrower grip places more emphasis on the anterior deltoid and triceps brachii. A shoulder-width grip offers a balanced activation of these muscle groups.

Limitations of EMG in Exercise Selection

While EMG is a powerful tool for exercise selection, it does have some limitations:

1. External Factors: EMG data can be affected by factors such as skin impedance, electrode placement, and individual variations, which may lead to variations in results.

2. Isolated Muscle Analysis: EMG mainly provides information on muscle activation of the surface muscles being measured. It may not fully capture the contribution of deeper stabilising muscles during complex movements.

3. Lack of Context: EMG data, while informative, should be considered alongside other factors such as exercise mechanics, load, and individual biomechanics to make well-rounded exercise choices.


EMG, or Electromyography, has emerged as a valuable tool for exercise selection in bodybuilding and fitness training. By providing insights into muscle activation patterns and recruitment, EMG analysis allows athletes to target specific muscles more effectively, optimize exercise techniques, and address muscle imbalances. However, it is essential to consider EMG data in the context of other factors and consult with fitness professionals to design comprehensive training programs for optimal muscle development and performance. With EMG, bodybuilders can enhance their training approach, making strides towards their fitness goals and achieving remarkable results in their bodybuilding journey.

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