By Evan Midford, Website & Social Media Coordinator
A while back, I was having some issues with my Patellar Tendon which led me down a path of learning how I could help fix the problem (patellar tendinopathy) and get my knees feeling better and free from the pain of 50+ years of the wear and tear of running, jumping, playing multiple sports, squatting, lunging, and deadlifting. This type of injury is not specific to old guys like me however as many young athlete’s experience things like jumper’s knee as they are growing and developing as athletes.
I like to consider myself to be athletic, and I want to stay that way for as long as possible, but that’s hard to do if my joints are stiff and sore. As I investigated tendon health further through reading articles, listening to various podcasts, and taking in person and online courses, I found that there were a handful of methods that can help joints move better and handle more stress and become more resilient. One of those methods involved isometric exercises. I have found that Isometrics have helped me improve my tendinopathy to the point where I am able to run, jump, change directions and sprint which at the ripe, old age of 52, I am happy with. If you want to keep your joints healthy, learn how to get into and feel the positions an athlete needs to get into for their sport and prepare the body to handle the loads that sport puts on it, join me for the next few minutes as we go through the ins and outs of isometrics.
Let’s kick this off with a little physiology shall we.
Muscular Contractions
There are essentially 3 types of muscular contractions: concentric, eccentric, and isometric.
Concentric muscle contractions are those where the muscle shortens under tension. An example of this would be lifting a barbell from your hips to your shoulders as in a bicep curl. The Biceps muscles are shortening as the bar gets lifted.
Eccentric muscle contractions are those where the muscle lengthens under tension. Again, let’s use the bicep curl as an example. Lowering the barbell from shoulder height back down to the front of the hips with control is an eccentric contraction where the biceps muscles are lengthening under tension from the bar.
Isometric muscle contractions are those where the length of the muscle does not change under tension from an external load (body weight, barbell) or an immovable object (a wall, pins on a squat rack, etc.). From a muscle physiological perspective that is not completely accurate, the muscle shortens slightly while the tendon (connective tissue that connects muscle to bone) lengthens slightly. The reality is that there is no change in the joint angle while performing an Isometric contraction. The research done by Dr. Keith Baar at the University of California – Davis shows this change in tissue lengths but not in joint angle.
Isometric contractions can be further broken down into two different types of exercises: (1) Yielding Isometrics and (2) Overcoming Isometrics.
Yielding Isometrics use a load that is less than maximal and held at a particular joint angle(s) for example a Glute Ham Raise Single Leg Iso Hold as seen in this video:
In this exercise, the athlete holds a slight knee bend in the working leg while holding the upper body in a parallel position to the floor for five seconds and then alternates legs after each five second repetition. Research shows that isometric exercises strengthen the working muscles at that specific joint angle plus or minus 10-15 degrees.
Most gyms do not have a Glute/Ham Raise bench so here is an alternative exercise that only requires the use of two benches or boxes, please note that this can also be done on the floor without any equipment. Here is the Long Lever Glute Bridge Iso Hold:
For a regressed (easier) version of this exercise, here is the Single Leg Glute Bridge Iso Hold – Back on Bench:
Overcoming Isometrics are performed at or above maximal load, so you are trying to exert maximal force against an immovable object. As you will see in the Split Squat Overcoming Iso Hold video below, we are working on strengthening at a specific joint angle for that movement. The athlete is creating maximal tension in the body for a prescribed period on each repetition, in this case 5 seconds per repetition.
Keep in mind that this is a more advanced exercise, and it would likely take months, or longer, to progress to this within a training program. Performing overcoming isometric exercises is also a great way to provide what we in the strength and conditioning world call a Post Activation Potentiation (PAP), which is a fancy way to say we are preparing the body to produce maximal force and promote explosiveness for another exercise.
For example, pairing the Split Squat Overcoming Iso Hold (2-3 reps of a 5s max effort with 10s rest between reps) with a Plyometric Exercise like a Quick Drop Split Squat Jump as seen in the video below for 4-6 reps per side. We would do this for 3 to 4 sets in our programming with at least a 2-minute rest between sets to allow for full recovery so each set is performed with maximal effort:
Implementing Isometric Training Into Your Program
For joint health and specifically tendon health it is important to work towards achieving up to 2 minutes of isometric loading on the muscles and connective tissues one to two times a day. Dr. Keith Baar recommends 4 sets of 30s holds to achieve the 2 minutes of loading required for tendon health. This may start out as 2-3 sets of 3 repetitions of 10 second holds. Over time the athlete can decrease the number of reps and increase the total time of the isometric hold until they are at 1 repetition of 30 seconds per set, working up to 4 sets. Once that becomes easy, it is recommended to start adding load to the exercises to further challenge the body. Keep in mind we would use Yielding Isometrics early on in any program but specifically in trying to heal a tendinopathy.
- Side Bar – Nutritional Strategies to go along with 2 minutes of isometric loading for tendon health. Again, the research by Dr. Baar leads the way in this area. He and his colleagues recommend 15-25 g of collagen supplementation taken with 50 mg of Vitamin C 60 minutes before training to allow for the amino acids and collagen peptides to peak in your blood for the training/rehab session.
Isometric training for improving sport performance is fairly sport specific. For example, when a sprinter is trying to improve the amount of force they put into the ground, they would work at that specific joint angle to do so. Below are two images, one is of a Sprinter Overcoming Isometric exercise (right) as well as an image of the plant phase of the sprinting stride (left). As you can see in the middle image on the left the runner’s position exactly matches that of the athlete performing the isometric exercise on the right.
The athlete in the picture on the right is using a Smith Machine and is in the plant phase of the running stride with the ball of the foot elevated on a small weight plate to emphasize the ball of the foot striking the ground as it would in a sprinting stride at maximal velocity. The athlete will then create maximal force in the body from the floor (plate) to the shoulders into the barbell.
Alternatively, a hockey player or speed skater will focus more on isometrics in greater joint angles as they are often trying to create force from lower positions. This can be seen in the Split Squat Overcoming Iso Hold video earlier in this article.
Finally, remember that strengthening at specific joint angles through isometric exercises also helps develop strength +/- up to 15 degrees on either side of that joint angle. This is where being able to get into those positions and develop that strength is important. It is also important in the rehabilitation process where a therapist would try to work in a pain free range of motion/joint angle and hope to build strength outside of that joint angle through isometrics and gradually work into that sport specific joint angle as they prepare athletes to return to play. Rehab is not the scope of this article so I would refer you to Sport Manitoba Clinic for information on the services available there: https://www.sportmanitoba.ca/clinic/.
Below is a quick overview that highlights the programming recommendations for incorporating isometric exercises into a training plan. Keep in mind that these are guidelines and exercises should be progressed as over time.
Yielding Isometrics
- Can be implemented early in a training program. Used in rehab settings as well. Helps athletes feel the positions they need to get into in their sport.
- 2 – 4 sets
- 1 – 3 reps
- 10 – 30 seconds
Overcoming Isometrics
- More advanced training method that requires a more mature training age. Maximal effort and force production required.
- 2 – 4 sets
- 2 – 3 reps
- Up to 5 seconds
Check out this infographic on isometrics for more information.
For more information on isometric training, I would encourage you to look into the following strength and conditioning professionals as they have done extensive work in this area: Dr. Keith Baar, Alex Natera, Cal Dietz, Chris Korfist and Jeff Dolan. They are leaders in isometric training for sport performance and who I’ve learned from on the topic.
Happy training and good luck with adding isometric for more information on isometric training please contact us at performance@sportmanitoba.ca or call us at (204) 925-5751.
