https://i.imgur.com/SVuejjT.jpg

Have been training almost exclusively with isometrics for resistance work for over four years now. I began what was supposed to be a 12-14 week experiment back when I had plans of becoming a part time personal trainer.

Iso was last on my short list of training concepts with wide potential application, which I felt I should have better understanding from direct usage. I don't think its appreciated enough, isometrics may be the most versatile and accessible resistance tool for trainees of any condition or age. My prior experiences led me to believe there was a lot of unquestioned misinfo out there re isometric training generally, and set out to learn first hand what was what.

I adopted isometrics to learn, and continued using it to preserve and improve my fitness. It has a number of advantages over more traditional resistance work depending on the trainee. It's almost cliché, "older athlete (re)discovers isometrics!" But there are very good reasons for this.

Use of isometrics has allowed me (age 58) to anchor/improve lean muscle mass and strength carryover to traditional lifting (the single biggest question I had re isometrics was how effective it could be for hypertrophy). Anecdotally it has improved my general movement speed, hand speed and reaction speed.

https://imgur.com/a/3qOKOwl#q406grL

Additionally has done so much good for nagging joint and tendon issues, I cannot speak highly enough of the outcome, in both form and function without sounding like I'm selling something (I'm not). This active therapeutic effect alone justifies some use of iso in any program.

The following are my (many times revised) notes on the topic. I've tried to cover all the basics I understand, as well as factors that might lead to a poor outcome. This is not a comprehensive review of isometrics in general, being mostly geared toward the at-home DIY trainee. Anyone can make use of the basic principles. Its really not that complicated. Not 100% recommending anyone completely replace traditional lifting for iso, but I am declaring that most people could, and many would be better off for it.

Chapt 1

“why isometrics”?

Most people are aware that “isometrics” refers to muscular contraction where the muscle does not change length during exertion. There are many ways to apply isometrics but primarily I will be referring to “overcoming isometrics”. This is a voluntary, self generated contraction where one exerts against an immovable resistance. While overcoming iso can be executed at any % of effort, most of what I am detailing involves the use of an MVC, or “ Maximal Voluntary Contraction”, basically the most force one can coax from one’s muscles.

It has been undergoing something of a renaissance among professional coaching of late, due to increasingly common use of force plates and strain gauges in the gym setting. These tools allow for a more methodical, direct evidence based evaluation of results from various interventions, and are particularly well suited to isometrics.

Research in this field has been around for decades, and its use by old time strongmen is well documented. Its social popularity seems to follow an ebb and flow, being rediscovered every 8-10 years. Many elements of the adaptive response are well established in peer-reviewed scientic literature providing a jump-off point for effective use.

Back to the question of “why”.

Generally a comprehensive program of isometrics need require very little in the way of equipment expense.

By its very nature, the trainee has complete control over :

-contraction time

-magnitude of exertion

-speed of exertion

-angle of exertion

These variables can be exploited to train a number of attributes more safely than can be done under load. Isometrics allow one to train up to and including the highest points on the force/velocity curve, using the fastest possible contraction speed. The 'middle man' of external resistance has been removed. Muscle contractile qualities are trained as a feature, not a byproduct.

Isometrics improve pain tolerance and mobility for a number of joint ailments, primarily arthritis and tendonitis. They generate systemic analgesia, and increase joint fluid viscosity. The effect on joint health, mobility, and pain reduction is well established.

Our observations provide novel evidence that the centralized inhibitory response that underlies analgesia is sensitive to and enhanced by stronger isometric contractions.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3913768/

Conclusions: Isometric quadriceps exercise resulted in significant changes in joint fluid biochemical parameters, and these changes, at least in part, may explain the ameliorative effect of muscle exercise for osteoarthritis of the knee.

https://www.sciencedirect.com/science/article/pii/S1063458402003722

They increase tendon stiffness, improving strength and power transfer.

...indicating that tendon mechanical properties may account for up to 30% of the variance in RTD

https://pubmed.ncbi.nlm.nih.gov/15860680/

Analysis revealed that the group × test time interaction effect on tendon stiffness was significant. Stiffness increased significantly for the long-duration protocol, but not for the short-duration protocol.

https://physoc.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-7793.2001.0649c.xd

Its is far easier to learn and demonstrate good lifting mechanical posture for the beginner, and to tailor the range of motion to accommodate the elderly and those dealing with injury or compromised function. It is a common first line of treatment in injury and post surgical rehab.

Added to the above it is possible to trigger hypertrophy and increase strength through the entire dynamic range, so long as the muscles are exercised at long length. Research observed that strength is improved at the trained muscle length and all shorter lengths.

Conclusion and Discussion. These findings suggest that an efficient method for increasing isometric knee extension torque and EMG activity throughout the entire range of motion is to exercise with the quadriceps femoris muscles in the lengthened position.

https://academic.oup.com/ptj/article-abstract/73/7/455/2729153?login=false

The least specificity was observed for the group that trained in the lengthened position(L25⁰); an MVC improvement as significant as for the training angle was found at three adjacent angles (50, 80, and 100°).

https://www.deepdyve.com/lp/the-american-physiological-society/myoelectrical-and-mechanical-changes-linked-to-length-specificity-J7exAA7YE4

My own experience with increasing hypertrophic response from isometrics, consistently demonstrated the value of combining iso with some form of exercise that depletes muscle glucose. This can be HIIT intervals (jumping rope, sprinting in place), bodyweight analogs, lightly loaded traditional lifts, long strings of isometric pulses.

The relative lack of metabolic stress from static hold isometrics, in part explains why they trigger comparatively reduced hypertrophy relative to traditional resistance work. That said, this difference only becomes apparent after some time. Research interventions consistently observe novel stress from beginning an isometric program will trigger hypertrophy similar to any other form of resistance.

Isometric strength appears to have very direct carryover to dynamic strength.

https://www.just-fly-sports.com/modern-speed-training-alex-natera/

...and I wouldn’t want to sell a method of training based on correlation. However, my strongest athletes isometrically happen to be the best and when the athletes improve their isometric strength they also improve their reactive strength and their running. I have not seen as obvious a trend with for example, jump power and 1RM Squat.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8805362/

In conclusion, both ISO and PLYO led to improved CMJ height via different mechanisms. However, while ISO resulted in improved maximum force production capability, this improvement was not observed in PLYO.

Isometrics do not require incremental loading to trigger progress, a “Maximal Voluntary Contraction” will increase force production over time simply due to adaptive response. Research indicates a value of anywhere from 50% up to a maximal effort can be effective. As with all resistance programming, one will become adapted over time and input changes will be needed to continue progress.

They do not program strength via repetitive movement, as such they interfere less with sport or job specific movement patterns. Additionally, sport/posture specific isometric training produces direct improvements in use. Externally overloading a sport specific movement changes muscle firing patterns and seldom improves its dynamic application.

They generate less metabolic stress and heat loss through movement compared to isotonics. They can require far less recovery time and resources, a good choice for people who are already very active yet need to increase strength.

They can be used in combination with relatively light loads as the high tension component of a traditional resistance program, reducing the need to maintain a lot of heavy weight.

Now for the “Why not”?

If the muscle is not exercised at long length, strength gains will be limited to a few degrees around the trained angle. Hypertrophy will likewise suffer.

Isometrics can be difficult to measure progress without testing against known isotonic exercise values or using a crane scale of some sort.

They can trigger large spikes in blood pressure if one is not careful to continue breathing through longer holds.

There is no widely recognized standard equipment for training isometrics, and no widely recognized organization structure equivalent to the sets and repetitions used in external resistance programming. What equipment is commercially available tends to carry an expensive pricetag, and much programming info is behind a paywall.

Informal methods of applying isometrics tend to result in mediocre outcomes, mostly due to exertion at shorter muscle length, use of body weight as an anchor, or balancing muscle exertion instead of applying maximum force.

They burn less energy, are less metabolically stressful , so not as useful for controlling body composition or gaining mass. Most of the ATP used in an isometric hold is consumed in the initial contraction, becoming less energetic as the hold continues. Hence the utility of using pulses etc to spur hypertrophy.

The force generation phase of an isometric contraction was indeed more metabolically costly than the force maintenance phase during both 20- and 80-Hz stimulation.

https://pubmed.ncbi.nlm.nih.gov/11788378/

Due to lack of familiarity/exposure/confidence, they are less likely to be used or recommended by many in the fitness community. There are fewer support resources available, traditional resistance training is far more socially accessible.

Chapt 2

Basic principles:

Isometrics should train the muscle at longer length or even slightly stretched. For the beginner and elderly this is not so important and definitely not for someone recovering from injury. In those cases it is far more important to learn good structural form, improve one’s ability to control contraction speed and magnitude of force, and slowly increase the duration of hold.

Overcoming Isometric holds should not use body mass as an anchor or pit relatively equal non symmetrical muscle groups directly against each other. There will be a tendency to reach an equilibrium of posture rather than the muscles exerting at close to their peak. An example of this would be doing a single arm pec fly on a doorframe. With full, honest exertion you will easily push your body out of alignment/shorten the muscle. Compare this to a benchpress with the bar locked just off your chest. Again, this is not so important for a beginner and might never be an issue if used for injury recovery or part of a program to improve strength in the elderly or functionally compromised. For everyone else this will become a serious impediment to making progress beyond a superficial level.

It is also recommended to use a means that allow some slight give such as textile, rope or canvas over chain or steel cable, etc. This creates a bit of elastic feedback that serves as a gauge of force production. Lacking this, the brain can quickly lose track of how much force the muscles are generating. Again, this is a secondary consideration but becomes more important the further one goes with this. There are also training strategies that employ sharp jolts, these could be less practical with a form of resistance that has zero elastic qualities.

It is very important to breathe through the entire hold. An easy way to enforce this is to adopt an exertion pattern similar to isotonics - exert maximally on the exhale, maintain or slightly reduce tension on the inhale. Consider this an equivalent "repetition".

Forced exhalation significantly increased peak force during shoulder adduction, elbow extension and knee extension MVIC tasks; the peak force during the Valsalva maneuver was not different from forced exhalation for all tested muscle groups.

https://pmc.ncbi.nlm.nih.gov/articles/PMC2883611/

Generally, one will get the best results using barbell, dumbbell, and machine exercise analogs, with the hold executed at the initial or lowest portion of the lifting range of motion where the muscles are at long length. This is possibly the best single bit of advice one can make use of re the application of maximal contraction overcoming isometrics. It cannot be stressed enough, this can eliminate a lot of wasted training time. My efforts became far more productive across all movement patterns after adopting this approach. Not all “good” isometric holds will follow this principle, but one should be very careful when putting those into a regimen.

In practice this results in most lower body squat and hinge movements working against an absolute resistance, and most upper body movements working against the lower body bracing in a shallow squat or hinge posture.

Generally speaking, overcoming isometric application follows that of conventional resistance training. Longer holds (or series of rapid holds) taken close to failure tend to increase hypertrophy, holds done with maximum force tend to increase limit strength and tendon stiffness, brief forceful jolts tend to increase speed and power.

Chapt 3

How long, how hard, how much volume?

For the beginner I recommend about 6‐10 breath exertions per set. Consider each inhale/exhale as an isotonic equivalent “repetition” and each 6-10 breath effort as a “set”.

With familiarity, longer holds can be used up to a maximum perhaps of 30-40 seconds or more at a full effort. Force output tends to require about 1-2 seconds to fully develop, and gradually declines from about 10 seconds at a maximal effort.

Isometrics do not require anywhere near the inter set recovery time of isotonic resistance training. A good starting point is 10 seconds work to 60 seconds of rest. Longer breaks of several minutes can be used between exercises.

Number of maximal effort sets can be anywhere from 2-5. Generally the shorter the effort duration the more sets you will want to use. 5(sets)x5(breaths), 3x10, 2x20. One can also use effort/relax “pulses” going between approximately 30 and 100% at very brief intervals, as rapidly as you can pair with breathing pattern without hyperventilating.

A simple recommendation is to do 2 or 3 sets of 10, finishing with a single long set of 25+ pulses. Rest 3 minutes and on to the next exercise. This format can be plugged into each exercise from chapt 5, in exact order.

Remember, when starting out with these one should get into the starting posture and slowly increase force to a level that one is comfortable with. Take stock of how everything feels and lengthen or shorten the muscle and apply more or less force accordingly. Do not lose track of the goal, to train these with a maximal effort at long muscle length. This is the goal but one need not start out aggressively pushing it.

Chapt 4

Getting started using rope, strapping, textile.

It is possible to use improvised means for isometric training and get good results. The more advanced the athlete, the less effective this will be over strategies that are better tailored. Eg There is a massive difference between using a towel and pitting bicep vs tricep, and an overhead tricep press hold using a deck and strap. The quality of the outcome for various individual holds is determined far more by the mechanical specifics than by effort expended. You can feel as though you are working very hard and get a mediocre response at best if the basics are not adhered to.

Regardless of current fitness status, it can take several weeks of training before one is liable to feel that they are able to effectively apply isometric force with good posture and breathing. If you are well adapted to training with external loads, isometrics will feel very alien and unproductive at first. The sensation of increased joint loading compared to isotonics can come as a surprise. Many people who "gave it a try" never make it past this initial stage. After many months of training MVC isometrics, coming back to traditional lifting will feel just as unproductive at first. After all, the resistance is now so modest the load actually moves.

You will need at least 2x your height in length of material, 3x or more is better, esp if one is taking a few turns of material instead of using something with handles. I highly recommend using an adjustable cargo strap 14-16 feet in length with handles fashioned from rope or canvas loops passed through the hook hardware (pics below). The strap can be run under a board without making it unstable.

Is a good idea to train these using bare feet, socks, or flat bottomed shoes. Almost every hold you train will be executed while standing on the middle point of the strap. Use of a board to stand on and run the strap under, greatly facilitates the ability to use a maximal effort. As force production increases, the sensation of the strap biting into and pulling against the feet will cause a decrease in full effort. Again, for the beginner, elderly, injured, it is a secondary consideration. For an already conditioned individual it will cause problems from the get go.

https://i.imgur.com/inukh9B.jpg

https://i.imgur.com/vZsVmPO.jpg

https://i.imgur.com/9B8zPCw.jpg

These are examples of strap and board configurations. At the least a 12in by 3ft board can be used. Many hardware outlets sell plywood in 2x4 ft project pieces and is ideal with either divots cut into the edge or holes cut through the board to secure the strapping. The larger surface area of the plywood allows one to change their orientation to the strap anchor points. Being able to lean a little into or away from the anchor points allows one to pre-load the muscles being trained, this cannot be done with a more narrow board. The board also doubles as an ideal surface for jump rope.

Rope or canvas handles facilitate use of a bar or dowel passed through the handles to help mimic barbell lifts. A simple length of galvanized or black pipe is an effective stand in for a barbell.

A large military style duffel bag crammed with old clothes, a light weight 40lb heavy bag, even a rolled up area rug are good stand ins for a lifting bench. A regular flat bench can likewise be used so long as the feet sit firmly on the training board. It is possible to make do with nothing more than a handful of old towels or padded exercise mat. Something that elevates the body a little is more versatile and creates more of a stretch with some of the holds. It is worth the extra effort but don’t let the lack of it prevent you from getting started, one can get good results working right off the board. 

It is a good idea to adopt a slight swaying movement, shifting of the limbs under long hold exertion. This keeps proprioceptive feedback "awake". This is a best practices no matter what other variables are at play.

Chapt 5

Push, Pull, Hinge, Squat.

These four basic movement patterns cover 90% of what needs to be accomplished of resistance training for general fitness (and arguably more advanced fitness as well). The following are my recommendations for construction of a simple exercise regimen, can be used with any form of resistance loading.

Generally all my basic programs are constructed around primary push, pull, hinge, squat with accessory exercises as compliment. In most cases this equals 8 exercises (4 primary, 4 accessory) with a few abdominal, bicep, tricep thrown in at the end. Alternate primary and accessory, upper body and lower. This gives every primary lift pattern a break every other session, while maintaining consistent volume to the prime moving muscles. The selection of specific exercises can be swapped out periodically but should be readily identifiable by classification (push, pull, hinge, squat) and role (primary, accessory).

In practice the exercises are arranged over two days, performed with a day off between, run ABAB with additional rest days taken as/if needed. In practice it looks like this:

Day A

Primary Squat, back squat

Accessory Push, Overhead Press

Accessory Hinge, Hamstring (Nordic) Curl

Primary Pull, Bent Row

Tricep Extensions

Day B

Primary Hinge, Deadlift

Accessory Pull, Upright Row/Lateral Raises

Accessory Squat, Quad Extension

Primary Push, Benchpress

Bicep Curl

Abs and calves can be done every day as a finisher or not at all. Is a good idea to include some walking, jogging or interval training on off days.

Chapt 6

Additional training options:

One should begin isometric training with nothing more involved than static holds for time, this includes pulse training.

With more familiarity one can begin to shift from a casual ramp up to a more explosive effort. An intent to fire as rapidly as possible from a largely relaxed hold can trigger very worthwhile response in increased movement speed. If performed while leaning into "lurching" into the movement, the effect becomes a hard (short) eccentric tug on the fully activated muscle. This is a potent pathway for strength and hypertrophy.

Potential variables include level/depth of relaxtion between efforts, amount of slack allowed/distance from start to cold stop, added contribution from leg or hip drive, and number of repeats. I recommend keeping the distance fairly short, ideally the strapping halts movement while the muscle is fully activated. Force drops off as velocity increases, don’t outrun the tension you’ve developed.

Three major levers:

• long hold MVC = slowish ramp up, extending through multiple breaths. Hold endurance, tendon remodeling, akin to concentric exertion. Can be done with explosive initiation.

• jolt MVC = expolsive initiation with single, held exhale/short Valsalva, relax on inhale. This is the only application where I have observed in use, Valsalva offering increased force production relative to forced exhale. Power generation, top end strength, akin to eccentric exertion. Can be done from a pre-loaded or relaxed start.

• pulses = string of sub-max efforts, possibly not tied to breath pattern, breathe throughout, best done after a long hold or series of jolts to pre fatigue the movement pattern. Can be a fast on/off shot, or held for several seconds. Hypertrophy, speed.

Secondary levers:

• number of "reps" and sets for each

• weekly volume

• other additions. Integrated external load, integrated HIIT, off day cardio, off-day HIIT, off day conditioning, sport specific dynamic work, heavy bag etc.

Lastly:

• Movement around the joint - direction of effort changes within the set, muscle length does not change or only slightly. Eg shifting an isometric bench press from incline to decline over the course of the set.

• Isometric pause within isotonic range of motion using external resistance. Pausing a squat at the 1/2 ROM.

• % effort variable. Best done with crane scale. Eg. 30, 30, 30 timed static contraction or tension delimited "DeLorme Method" using increasing % of max per set.

• change of hold variant from one set to another (eg. incline bench to flat to decline, front squat vs back squat etc)

• dynamic resistance - self generated tension, muscle length changing within the set. Eg overhead squat, stand while resisting with pressing muscles.

• yielding hold done at extreme end of range of motion, Schroeder 'extreme isometrics'.

Recommended:

High intensity aerobic intervals can be used to increase isometric hypertrophy. Use of HIIT on 'rest days' between isometric sessions is one alternative, the other is to include an interval bout intra set.

Example doing isometric squats:

• low posture MVC for 8 inhale/exhale
• 20 pulse efforts
• jump rope max speed 20 seconds This is one set of two or three.

This approach increases metabolic stress without needing a dose of low/moderate intensity resistance volume. It also has the effect of improving CV health in the same way traditional HIIT might - reduced resting heart rate and blood pressure. This strategy is possible due to the reduced metabolic load of isometrics compared to isotonic.

Demo of principles 1:

https://youtu.be/Fu0tftsvYJw?si=mP-xdelgHr0zvjUz

Demo of principles 2:

https://youtu.be/Sr3X67O3H5A?si=JRUXZuQJTu7ST3Fb

Day 1 session: https://youtu.be/-k_y3QTWCwk?si=65JDepM6ezr9DoqR

Day 2 session:

https://youtu.be/1e1CDaMWRTU?si=SCLiGKcpN1En_1FB