Q&A: Gaining Muscle Mass With Isometrics

Question: Drew, do you think it is possible to gain muscle mass with isometric training only, assuming a time under tension of 60-90 seconds?

Answer: Yes, it is possible to increase muscular strength and size with only isometric training if you do it with a a high intensity of effort, and a broad range of times under tension can be effective including sets lasting sixty to ninety seconds.

Over the past twenty years I have experimented with a variety of isometric protocols using very different set durations, from Max Contraction Omega sets lasting only a few seconds to timed static contractions lasting up to ninety seconds and many others in between. While different methods of isometrics have their advantages and disadvantages all of them are effective ways to build bigger, stronger muscles.

Isometric exercises do not have to be performed for very long to effectively stimulate muscular hypertrophy. Some of the earliest research on isometrics showed significant strength and size gains could be achieved with a few contractions lasting only six seconds if they were performed with maximum effort (Hettinger, T. and Muller, E. A. Muskelleistung und Muskeltraining. Internationale Zeitschrift fur angewandte Physiologie einschliesslich Arbeitsphysiologie, 5: 1 11-126, 1953) and John Little’s Max Contraction Omega Sets which consist of a few reps of even shorter isometric contractions followed by a partial negative have also been effective for increasing muscle mass. Despite the effectiveness of very brief isometric protocols I recommend using a longer time under tension to allow for a built-in warm-up and to simultaneously stimulate improvements in metabolic and cardiovascular conditioning. I’ve been using sixty to ninety second static holds and timed static contractions on various exercises with many of my personal training clients as well as in my bodyweight high intensity training and timed static contraction training programs

Timed Static Contraction belt squat

When I last worked with SuperSlow founder Ken Hutchins we trained many people on machines he designed specifically for timed static contraction training which measured and displayed their force input in real time. Clients were instructed to gradually increase the force they applied over a period of ten to twenty seconds up to a specific level and to maintain that for the remainder of ninety seconds. The length of time they were able to maintain their target level of force was recorded, and if they could maintain it until reaching ninety seconds we increased their target the next time they performed the exercise. Using this ninety-second protocol we saw consistent, significant strength increases, and these translated to full-range strength gains when the exercises were performed dynamically as well as visible increases in muscle mass in many trainees.

While the longer isometric contractions were just as effective for improving muscular strength and size – just like a broad range of repetitions can be effective with dynamic exercise protocols – unlike the shorter isometric protocols I’ve experimented with previously they also had a significant metabolic and cardiovascular effect. It was not unusual for clients to experience significant increases in breath and heart rate when performing ninety-second timed static contractions on compound exercises. Also, unlike the shorter isometric protocols the longer timed static contractions did not result in post-workout joint pain or discomfort for some clients, which is reason enough to err on the longer side.

I cover the use of timed static contractions and static holds for a variety of exercises in my books Project Kratos and Timed Static Contraction Training.

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  • Mateo May 16, 2016 @ 14:40

    Thank you, very useful information as always. There is no doubt that if someone is willing to train hard enought, the equipment used makes little diference.

    • Drew Baye May 16, 2016 @ 19:49

      Hey Mateo,

      You’re welcome, and you’re right. As long as you are training hard, progressively, and consistently, with a volume and frequency appropriate to your body and goals, you can get good results with a variety of exercise methods and equipment.

  • Blair May 17, 2016 @ 13:25

    Hello Drew,

    I use primarily the Project Kratos book’s workouts, and am very satisfied with them. About every five workouts or so, I will do the basic full-body workout from the TSC book, which gives me a great workout. Once and while, during a TSC with a moving strap, I sometimes will have to adjust my hand or re-grip the moving strap, which will cause the targeted muscles to relax for a second or two. When this happens, I will sometimes extend the TSC another 5-10 seconds beyond the 90 second mark, if I can, just to make sure I get the most out of the exercise. Would you recommend exceeding the 90 second mark for such a purpose? And generally, should I extend the 90 second mark, if I feel for whatever reason that I have a little left. I should point out that this happens very rarely in a TSC. Thanks for all the great work you do.

    • Drew Baye May 23, 2016 @ 16:43

      Hey Blair

      I’m glad you like the workouts in Project Kratos. If you only need to relax for a second or two to adjust your grip there is no need to extend the set. If you feel like you can maintain max effort for a little longer at the end of a TSC there is no harm in doing so, but if this happens regularly I recommend focusing on contracting even harder during the final phase.

      • Blair May 24, 2016 @ 6:18

        Thank you for the response. The advice is helpful, and I appreciate it.

  • John Beynor May 19, 2016 @ 11:24

    Hey Drew,

    I use a seated leg curl machine to perform a TSC/Max Contraction leg extension regularly because thats all I have available. The lever arm can only be set outside of 90 degrees and have used the different settings, but mostly close to full extension. Because there’s no lap restraint I have to grab on to the sides of the seat and find myself straining at times and have to be careful because of a neck and upper back injury. Do you think this is ok and maybe I reached my limit with this?

    • Drew Baye May 22, 2016 @ 11:17

      Hey John,

      I recommend getting your own belt to use with this and other machines which should have one but often don’t (leg extension, trunk extension, chest press, shoulder press, etc.). You can purchase side-release buckle belts from places like Strapworks which work well for this, as well as other TSC exercises. A two-inch wide, five-foot long belt will fit around your waist or thighs and the seats or benches of most machines. With the belt fastened tightly and the movement arm in the mid-range position you should not need to pull on the seat very hard, if at all, reducing the stress on your neck and back.

  • Robert Jul 22, 2016 @ 19:56

    Hi Drew was wondering about max contraction. Does a muscle have to be in its fully contracted position to stimulate all the muscle fibers?

    • Drew Baye Oct 8, 2016 @ 17:52

      Hey Robert,

      No, because stimulation depends on recruitment, tension, and fatigue not length, and a muscle fiber can be recruited, produce tension, and be fatigued at any length.

  • John Beynor Aug 24, 2016 @ 15:27

    Drew,

    I’m planning on buying a belt from Strapworks. What length would be needed if I also want to use for other isometric exercises, especially TSC squats? What about the buckle material? I’m also going to be buying some yoga blocks. My workouts have always been mostly isometric and I do like how the yoga blocks feel with some exercises. I workout at a college gym that’s not that good. I have used medicine/fitness balls to perform TSC chest fly’s and things like that.

    • Drew Baye Sep 2, 2016 @ 13:44

      Hey John,

      The belt I used for squats and other exercises was about nine feet long, while the side-release buckle belt I use for neck exercises is only about five feet. For the squats and other exercises I now use forearm forklift furniture moving straps, which have padded loops that work nicely for gripping and to loop around the feet for belt squats and heel raises.

  • ROCK Dec 4, 2016 @ 4:12

    your book is awesome.i just replaced two TSC exercise (squat , deadlift ) with TSC legpress. will it workout all the muscles that squat and dealift are supposed to work specially lower back. thank you in advance.

    • Drew Baye Jan 7, 2017 @ 18:47

      Hey Rock,

      While the leg press is a good substitute for working the hip and thigh muscles targeted by the squat and deadlift you would still need to add another exercise for your lower back muscles.

  • John Beynor Jan 22, 2017 @ 21:08

    Hey Drew,

    Can the forearm forklift straps or any straps work well when using them barefoot on the exercises where you would be standing on them, or do you need to be wearing shoes? Also is one strap enough? I’m going to start exclusively using only a pair of yoga blocks and a strap to workout out isometrically at home. I do need to buy your e-book.

    • Drew Baye Feb 3, 2017 @ 16:47

      Hey John,

      I usually work out barefoot and the straps work fine without shoes.

  • Patrik Nov 7, 2017 @ 6:45

    Hi Drew,

    I wonder how do I know if I train hard enough to reach Momentary Muscular Failure through TSC?
    I bought your book “Timed Static Contraction Training A Guide to Minimalist High Intensity Isometrics” and I´ll been training using that as guide.
    I often, especially when I do Shoulder Press begin to shake and losing good form, is that maybe a signal of Momentary Muscular Failure?

    ps. I also preordered your Q&A books and maybe you take it up there.

    Thanks for all your work you bring to all of us, you are truly an inspiration to HIT.

    Sincerely, Patrik.

    • Drew Baye Nov 8, 2017 @ 13:59

      The concept of momentary muscle failure does not apply to timed static contractions since you can not fail to lift or hold an immobile object. However, if you perform TSC correctly you still accomplish the goal of training to momentary muscle failure, which is to work the target muscles to the point where they are contracting with maximum intensity.

  • kurb conrad Jan 20, 2018 @ 17:22

    Hello Drew
    I am elderly and have lost some muscle weight over the last few years. I now weigh 115 lbs and want to regain 5 – 10 lbps, purely for health benefits. I came across Doug McGuffs body science book in which he says HI training and benefits apply to senior citizens. I am thinking of buying TSC with a view of simulating the five exercise that Doug uses on machines. Does this make sense, and any advise for the elderly. I have not done strength training. I attended workshop for kettlebell, but quickly realized that its too dynamic for me to execute safely. The metabolic health benefit and safety from HIT appeals to me
    Thanks, Kurb

    • Drew Baye Jan 21, 2018 @ 14:23

      If you work out in a gym and don’t currently have any injuries for which the exercises in the book are contraindicated they can all be performed safely when performed as described. If you work out at home you can substitute bodyweight or TSC exercises for those, using the methods in either my bodyweight training or timed static contraction training books.

  • Matt Feb 11, 2018 @ 20:27

    Hi Drew,

    How many times a week would you recommend a 90 second isometric routine?

    Do we need space between days?

    Thanks.

    • Drew Baye Feb 22, 2018 @ 8:42

      I do not recommend a 90 second isometric routine. Individual exercises may be performed isometrically for 90 seconds but a full workout with exercises for all major muscle groups will take about 20 to 30 minutes, depending on how long you rest between exercises.

      Two or three days a week on non-consecutive days works well for most people, but some people may require even more rest days between workouts for recovery and adaptation.

  • Matt Feb 22, 2018 @ 8:58

    Okay, that makes sense. I very much appreciate your advice on this one.

  • Tim Shearer Mar 13, 2018 @ 23:37

    Hey Drew,

    I’m a high school track coach (sprint/jump) and our spring season begins next week. I just bought some Forearm Forklifts as well as some 18′ long cam buckle straps with the idea of having them do timed static contraction training. I had planned on a protocol along the lines of the old standby of 7 second max contractions in 3 positions, but reading your preference for 60-90 second contractions has me in a quandary. Of course, my athletes require a considerable amount of skill/coordination work as well as actual sprint work near max. Consequently my thinking is that going for long contractions to momentary failure would not allow for adequate recovery for the other more specific work required for our sport. Thoughts?

    Thanks, Tim

    • Drew Baye Mar 14, 2018 @ 14:19

      The 90 second TSC protocol is deeply fatiguing but shouldn’t be so taxing as to interfere with skill practice as long as workouts are limited to one set of one or two exercises for each muscle group done only once or twice weekly in-season.

  • Wim Nov 19, 2019 @ 19:28

    Hello, i have only a few kettlebells, a pull up bar and a dipstation. I dont have room for a barbell or bench.
    Can i still follow the routines with the same results?

    • Drew Baye Dec 27, 2019 @ 9:47

      Yes. The timed static contraction workouts can be performed using just a long strap like the kinds you can buy at any home improvement store for moving furniture or towing and require very little space.