Static contraction training (consisting mainly of isometric training) can be an effective and powerful training tool, especially if it’s utilized over a variety of angles. An isometric muscle contraction refers to exerting muscular tension without producing an actual movement or a change in muscle length. However, it is seldom used because the overwhelming majority of those in the fitness industry and the strength and conditioning field, as well as competitive lifters, train more dynamically compared to direct isometric muscle contractions.

Functional isometrics involve performing static contractions at specific points within a range of motion. This is a critical component when training multi-joint compound exercises such as overhead presses and squats. For example, pause squats are an excellent choice to help accelerate squatting power from the hole. Incorporating pause squats with two-, four-, or six-second pauses employs static contraction activity (i.e. isometrics) for the glutes, low back, and core musculature. If one considers any given quality training program, there is actually more static contraction activity occurring over the course of any given session than one might realize. Strongman implements (i.e. farmers walk, keg carries) are one of the best examples that are often overlooked. These events utilize an incredible amount of static contraction (isometric) activity for many events and during training.

pic-farmers

However, although this type of training is unpopular compared to more dynamic training, research has reported that significant and rapid increases in strength occur as a result of isometric training. For example, early reports by Thépaut-Mathieu (1988) reported an increase of 25–54 percent in five weeks for training and testing sessions consisting of right elbow isometric flexion. An investigation by Weir (1995) found that strength increased by 27 percent in six weeks for isometric leg extensions when training three times per week.

One of the limitations of isometrics is that it only develops strength at specific angles. It’s “angle specific,” referring to the angle of the joint at which the strength is expressed. However, much of the training effect depends upon the joint angle. Research has reported that training at a specific joint angle leads to large strength gains at that angle but not at all other angles. So there’s a positive transfer of the strength gained within a 15–20 degree range, meaning that isometrics produce the strength gain in plus or minus 15 degrees of the angle worked.

Research by Folland and colleagues (2005) investigated the effects of isometric training at a range of joint angles versus dynamic training. Thirty-three recreationally active males were recruited who hadn’t performed any leg resistance training within the previous six months. They performed unilateral leg training for nine weeks, three times per week for the quadriceps. The subjects performed isometric leg extensions with one leg while performing dynamic leg extensions with the opposite leg. Participants were tested on the strength of each leg pre- and post-training. Isokinetic strength was assessed at three speeds (45, 150, and 300 degrees) and isometric strength at four angles of knee flexion (50, 70, 90, and 110 degrees).

For the isometric group, four sets of ten reps were performed of two seconds duration. Each set was performed at varying knee angles (50, 70, 90, and 110 degrees). The group took a two-second rest between contractions and a two-minute rest period between each set. Similarly, the dynamic training group performed four sets of ten reps on a variable resistance leg extension machine with a short pause between reps and two minutes rest between sets. The results indicated that both groups significantly increased the isometric strength of both legs at a range of angles. However, the gains in isometric strength were larger in the isometrically trained leg than in the dynamically trained leg at all angles measured.

An interesting aspect and take away from this study is that the gains in isometric strength at specific joint angles weren’t equal at each joint angle. Despite almost identical training with both groups, the gains in strength are larger at some joint angles than others. Furthermore, a recent report (2010) examined the relationships between measures of maximal isometric force, rate of force development (RFD), vertical jump (VJ) performance, and one repetition maximum (1RM) strength in 26 (age 22, 175 cm, and 90 kg+/- 10 kg) recreationally trained men. It concluded that isometric maximum strength determined during the isometric mid-thigh pull test correlated well with 1RM and VJ testing. There was a nearly perfect correlation between measures of peak force and 1RM squat (r = 0.97) and 1RM bench press (r = 0.99). The correlations were also strong between the vertical jump and peak force (r = 0.72) and 1RM bench press (r = 0.70).

As with multiple types of training, there are advantages and disadvantages of static contraction (isometric) training. Some advantages are that isometrics take less time and energy during a given training session, and speed-strength can be maintained. In addition, a great coach will also be able to observe technique at specific positions of a movement and determine whether or not technique remains optimal. Another benefit of static contraction (isometric) training is that it does lead to an increased activation of motor units and can enhance one’s ability to recruit motor units during a maximal contraction. However, isometric training isn’t for the weak, as it can tax the central nervous system heavily and probably does little for overall muscle hypertrophy. However, it can have a very positive effect on absolute strength. In addition, isometric training should only be used for short time periods, either when training progress has diminished or when a rapid strength increase is needed, such a preparing for a contest.

One of the best ways to incorporate isometric training into your program is to perform it by pulling or pushing against the pins. If you’re weak off the floor for deadlifting, incorporate the pull at a certain position (i.e. at the knee, below the knee, or even at lockout).

Keep in mind that when pulling or pushing against pins, you can use sub-max or max effort and anywhere from two, three, or up to eight seconds of duration. When you come to the end of the last concentric repetition, make contact with the bar against the top pins. Apply as much force as possible for the entire duration. Envision yourself trying to blast through the pins!

nother method of static contraction training is the implementation of quasi-static contraction training (incorporating a static contraction within a rep or between reps). This is another excellent approach for breaking through training plateaus. This can be accomplished by combining several seconds (i.e. three to five seconds) of heavy static holds between normal sets.

Despite that these methods aren’t usually employed for strength and power performance, they do elicit a positive effect on performance outcomes and can and should be used strategically within a training program.

References

  • Weir JP, Housh TJ, Weir LL, Johnson GO (1995) Effects of unilateral isometric strength training on joint angle specificity and cross-training. Eur J Appl Physiol Occup Physiol 70(4):337–43.
  • Thépaut-Mathieu C, Van Hoecke J, Maton B (1988) Myoelectrical and mechanical changes linked to length specificity during isometric training.  J Appl Physiol 64(4):1500–5.
  • Folland JP, Hawker K, Leach B, Little T, Jones DA (2005) Strength training: isometric training at a range of joint angles versus dynamic training. J Sports Sci 23(8):817–24.
  • McGuigan MR, Newton MJ, Winchester JB, Nelson AG (2010) Relationship between isometric and dynamic strength in recreationally trained men. J Strength Cond Res 24(9):2570–3.
  1. Amit says:

    I dont think farmers walk etc are really static. Perhaps farmer’s stand are, but walking creates small up-down movements. its a short-ROM long TUT movement.
    What’s your opinion?

    • Jon says:

      Amit, there is always a brief period of static contraction for farmers walks. Although it’s more locomotion than pure ‘holds’ there still is static activity for the grip, traps, shoulder, and core musculature, not to mention shoulder and scapula stabilization. The TUT is going to be depended on on the overall time and distance traveled as well. 15 ft vs. 200 is a huge difference.

  2. I hardly leave a response, but i did some searching and wound up here Static Contraction
    Training