Maximum Muscle Activation  

The main reason people make for not exercising is time. Everyone is under some variety of time crunch situations, either with work, kids, school we can all relate. Every single client I have met is looking for the highest bang for their time-commitment buck. This can be seen with the popularity of short workout videos and programs such as Tabata that provide the benefits of extended workouts without the time commitment that most need. Most people have been lead to believe that in order to gain muscle and sports performance they need to hit the weights for hours on end, until now.

Bret Contreras, a certified strength and conditioning specialist has developed a comprehensive study analyzing a variety of common exercises and which ones provide the best average contraction and the highest peak contraction on major muscle groups. This may sound overwhelming at first but let me explain. For individuals looking to gain lean muscle mass, the best way to achieve this is by constant or average tension on the target muscle. The higher the level of constant tension, the more microscopic tears in the muscle and eventually the bigger and stronger the muscle will become. In contrast, athletes looking to increase explosive strength will want to put the target muscle under the most total amount of tension or peak contraction. The muscle will become used to applying maximal effort and this will translate to a quicker and stronger contraction for a few short reps, which is optimal for athletes looking to gain explosiveness in a certain activity. By understanding what exercises are best suited for your goals you can shape a routine that optimizes time and results.

Muscular contractions are measured by using Electromyography (EMG), essentially EMG measures the quantity and quality of electrical signals fired by motor neurons that contact the muscle. So EMG measures the amount of force the body can exert on a muscle, thus providing information on how active a muscle becomes during an exercise. EMG works by placing electrodes across the muscle and measuring the speed and strength of the electrical signals between those two points. The baseline was created by applying these electrodes to the targeted body part then allowing the test subject to perform a maximal isometric flex. This isometric flex is seen as maximum voluntary contraction and will be the baseline of 100%, all other values listed are based off of a percentage of this voluntary flex. For example, if the subject performed a barbell bench press and the pectorals were observed to have a 115% average contraction that would mean that the exercise produced a 15% harder constant contraction then just flexing the muscle voluntarily.

The following tables show the best exercise for the “average value” and the best exercises for “peak value” for that given body part.  

Chest (Pectoral)

Muscle

Best Exercise Yielding Highest Mean

Average Value

Best Exercise Yielding Highest Peak

Peak Value

Upper Pectoral

Mid Pulley Crossover

154.0

DB Incline Press

310.0

Band Push Up

115.0

Guillotine Press

302.0

Middle Pectoral

DB Bench Press

204

Guillotine Press

511

Floor Press

132

DB Bench Press

451

Dumbbell Fly

133

Dumbbell Fly

493

Lower Pectoral

Weighted Dip

214

Guillotine press

502

Blast Strap Push Up

177

Dumbbell Fly

450

Guillotine Press

169

Weighted Dip

418

 

The majority of gym-goes would expect that the bench press would dominate this table but as seen it does not unless dumbbells are used. The pectorals main function is to draw the arm towards the midline, which is exactly what the mid pulley crossover stimulates. When looking at the middle pectoral all these exercises have the same main movement pattern with the elbows going behind to their furthest position from the midline of the chest, this allows for a greater stretch and overall contraction. The lower pectoral also responds well to this full stretch as see with the weighted dip and guillotine press. This table proves that the chest responds best to isolation exercises from many angles over the traditional bench press.

Shoulders (Deltoids) 

Muscle

Best Exercise Yielding Highest Mean

Average Value

Best Exercise Yielding Highest Peak

Peak Value

Front Deltoid

Seated Behind Neck Press

274

Seated Behind Neck Press

471

Seated Military Press

162

Standing DB Military Press

432

Incline Press

144

Incline Press

390

Middle Deltoid

Band Face Pulls

90.7

Band Face Pull

152

Lateral Raise

84.3

Lateral Raise

213

Seated Behind Neck Press

69.5

Cable Lateral Raise

136

Rear Deltoid

Band Face Pull

144

Band Face Pull

252

Bent Over Rear Delt Raise

94.7

Bent Over Rear Delt Raise

182

 This data confirms that pressing movements are best at stimulating the front deltoids. The behind the neck press eliminates the introduction of the pectorals and thus making it more effective. I will note that although that the behind neck press is rated as the most optimal it can be very dangerous and should be avoided by beginner and intermediate lifters. The most interesting part of this table is the effectiveness of the face pull. Many lifters have used the face pull for shoulder health and rear deltoid activation although it ranks the highest in terms of activation of the medial deltoid.

Arms (Biceps and Triceps)

Muscle

Best Exercise Yielding Highest Mean

Average Value

Best Exercise Yielding Highest Peak

Peak Value

Biceps

Weighted Wide Parallel-Grip Pull Up

 

109

Weighted Chin-Up

 

205

Weighted Chin-Up

107

Weighted Wide Parallel-Grip Pull Up

184

Barbell Curl

94.7

EZ-Bar Curl

146

Triceps

Rope Extension

135

Rope Extension

276

Cable Extension

132

Cable Extension

255

As this table shows, the best way to develop biceps is by introducing weighted pull ups and chin ups, which are already great back exercises. Thus, instead of doing multiple sets of curls you can cut down on time by incorporating weighted chip ups and pull ups to hit both your back and biceps effectively in a shorter duration. In contrast, the triceps respond much better to isolation exercises and most notable rope extensions for both lean mass development and peak activation.

Quads

Muscle

Best Exercise Yielding Highest Mean

Average Value

Best Exercise Yielding Highest Peak

Peak Value

Quadriceps

Half Squat

101

Full Squat

194

Parallel Squat

99.9

Parallel Squat

189

Quarter Squat

65.2

Band Skorcher Hip Thrust

172

Adductors

Single Leg Gliding Leg Curl

61.6

Romanian Deadlift

163

Hack Lift

47.9

Single Leg Gliding Leg Curl

120

Russian Leg Curl

46.5

High Step Up

104

 No surprises here as we should all know by now that the squat is king of quad development. The only notable item is that the quad is under the majority of average tension by not going past the half squat position. Thus if you are looking to build lean quad mass you do not need to continue with the full, deep squat. The adductors can be stimulated by squatting or leg pressing with a wider stance, this will help to engage and develop the often forgotten adductors. .

Hamstrings, Glutes & Calves

Muscle

Best Exercise Yielding Highest Mean

Average Value

Best Exercise Yielding Highest Peak

Peak Value

Gluteus Maximus

Band Hip Thrust

88.3

Band Hip Thrust

160

Glute Bridge

65.3

Glute Bridge

142

Pull-Through

61

Hip Thrust

138

Hamstrings

Dead lift

105

Rack Pull

181

Rack Pull

105

Dead Lift

179

Calves

Heavy Calf Raise

134

Parallel Squat

263

Explosive Calf Raise

124

Heavy Calf Raise

211

Single Leg Calf Raise

104

Pause Calf Raise

177

 Interestingly, the glutes seem to respond to more isolation-bodyweight exercises. This would shock the female bodybuilding community as it is believed that the squat is the best for glute development. Rack pulls and dead lifts are far away the best exercises to stimulate both tension and peak activation in hamstrings. Overall the calves respond to heavy loads, in order to save precious time, you can use parallel squats to target both the quads and calves for development in half of the time. As seen the calves respond to heavy rep ranges from roughly 6-10 reps, rather then the tradition marathon calve-burn sets.

Back & Traps

Muscle

Best Exercise Yielding Highest Mean

Average Value

Best Exercise Yielding Highest Peak

Peak Value

Lats

Weighted Chin-Up (Supinate Grip)

108

Weighted Pull-Up

(Pronated Grip)

167

Rack Pull

93.1

Rack Pull

163

Traps

DB Bent-Over Row




123

Prone Trap Raise

186

DB Elbows Out Chest Supported Row

100

DB Bent Over Row

126

Both of the weighted chin up variations supinate (underhand grip) and pronate (overhand grip) are at the top of the list for both average and peak contraction. The majority time saver is using bent-over dumbbell rows for both lat and trap development. No need to do a plethora of weighted shrugs to activate the traps.

After reviewing these tables I believe it is obvious to point out some factors that may have altered the results. In this case Bret developed the data mainly for bodybuilders or individuals trying to gain lean mass, that being said the participants were advised to pick weights that they could sustain for at least five proper repetitions with good form. This eliminates the majority of power lifting and Olympic lifters as they as more concerned with a single repetition and not the contraction power generated from multiple reps. Therefore, this data does not represent the muscle activity that would be generated from a one rep max effort. Also these tables are not a “one size fits all”, meaning that every person will have unique genetic and mechanical development that would alter these results significantly.

This kind of EMG study is in its infancy and should be taking with a grain of salt, I have implemented many of these exercises into my routine to cut down on time and hit multiple muscle groups synergistically. I have also steered away from the exercises I had become too comfortable with and implemented some of the exercises on this list that I had not done or did not enjoy doing.

Final thoughts and conclusion:

  • Barbell bench pressing did not make the list for pectoral development
  • Lat pull down is not one of the most effective exercises for engaging the lats
  • Deep, full squats are not the best for quad development
  • Bodyweight isolation exercises are better for glute development then traditional squats
  • Calves respond best to heavy weights and less reps
  • Medial and rear deltoids are stimulated best by face pulls
  • Weighted pull-ups and chin-ups are best for bicep development

Contributed by Matt Volpe, Canfitpro Certified Trainer

 

Resources:

http://bretcontreras.com/whats-fuss-emg/

https://massivejoes.com/articles/the-scoop/maximum-muscle-activation-training

https://www.t-nation.com/training/inside-the-muscles-best-chest-and-triceps-exercises

https://www.t-nation.com/training/inside-the-muscles-best-leg-glute-and-calf-exercises

https://www.t-nation.com/training/inside-the-muscles-best-shoulders-and-trap-exercises

https://www.t-nation.com/training/inside-the-muscles-best-back-and-biceps-exercises

https://www.t-nation.com/training/inside-the-muscles-best-ab-exercises

Karen Somerville