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Do You Actively Flex/Contract a Muscle During an Isolation Exercise?

Do you actively contract a muscle like during a dumbbell bench press, do you contract or squeeze or flex your pecs halfway up or do you just focus with your mind on contracting them?Or during a lat pull down so you actively flex the lats or contract them or just drive with the elbows?

I never consciously try and contract specific muscles during a movement, because that’s not a natural way to perform a movement, and it throws out the movement pattern. The contraction should be a result of proper technique, with an adequate load, with the right number of reps.

I do concentrate on cues for a certain movement, like initiating an upper body movement from the scapulars

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I just move shit with my mind


Not an isolation movement

Also not an isolation movement.

But in answer to your question, if i was lifting a weight for the purposes of targeting a certain muscle, I focus entirely on the muscle I’m aiming to target and not on moving the weight in my hands.


Unless it’s your heart or diaphragm, yes.

Very well said. Pretty much how I approach things.

so there are 2 concepts that can be addressed. One involves flexing particular muscles in an isolation exercise (the title of this thread), and the other is actively and consciously focusing particular muscles in a compound movement (what you end up actually talking about).

Let use a dumbbell curl for the isolation movements as an example. So the purpose of an isolation movement is specifically to target one muscle, or muscle group, while eliminating other muscles from ‘helping’ to move the weight. So for a dumbbell curl, the conscious aspect is not so much focusing on contracting the bicep: if you’re curling the weight, that’s already happening. It’s more that you’re avoiding contracting other surrounding muscles. You’re avoiding using unnecessary leverage advantages to accomplish the task. You’re avoiding engaging the shoulders, the traps, the lats, the hips, whatever. It’s a concentrated, isolated movement.

Compound movements are very different. In compound movements, it’s often the case that the goal is to recruit as many muscle groups as possible. So, generally, there’s still no reason to focus on contracting the prime movers. So in a squat, for instance, you don’t have to focus on engaging the quads. If you’re completing the movement, your quads did work. It’s a guarantee. What you have to focus on is engaging, or flexing, other muscles, for the sake of better performance and stability. So, you will focus on flexing the lats. The abs. You may focus on gripping the bar tight. Stuff like that. In a standing overhead press, I have to focus very hard on contracting my glutes and my lats to stay tight so that I am in a proper position to press the weight.

Now, something you can do on the exercises you specifically mentioned is working on focusing on the stretch in the eccentric portion, and the flex at the end of the concentric portion. So in the lat pulldown, when you have pulled the bar all the way down to its final position, you can then flex the lats hard, and maintain that position for a second or 2. There is some benefit in that. You can also make sure


I always focus on the muscle in isolation movements. That’s the point isn’t it?

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Exactly what I was thinking

My issue with that theory is that you can focus too much on the target muscle, to the neglect of your posture, joints and tendons. Even with an isolation exercise, the target muscle is still part of a chain.
eg with a dumbbell curl you might be focusing on the biceps contraction, and get a fantastic pump, intense workout. If you don’t pay attention to first packing your shoulders/scapulas so they lie flat with the back of the ribcage, your scapula can slip around to the front impinging the shoulder/bicep tendons, in the long run.

Similar thing with the lateral raise. You are told it isolates the medial delt. Even so your scapula, traps, rhomboids, teres are part of the movement chain. Neglect what is happening to these other areas in the chain and you will probably develop joint problems, especially if you train intensely.
Leg extension: You might get an insane contraction, and pump in the quads, especially if you hold the weight locked out at the top. In the long term most people will develop pain in the patellar region. I find this can be alleviated by feeling that you are extending the hamstrings during the movement. Counterintuitive but it works, and you still get a great pump in the quads without concentrating on the target muscle.

I think the answer is completely based off of your goals. If you are doing strength training, then besides bracing and other cues, movement patterns and form are king. If you are training for hypertrophy, taking full advantage of the MMC, despite altering the movement pattern to maximize contraction, is equally important.

I believe that any pro bodybuilder would strongly disagree with this statement:

However, from a strength perspective, this is a completely defensible statement.

kinda just seems like semantics.

like, in example i used above with dumbbell curls, you can think about it in terms of concentrating very specifically on, or consciously contracting the bicep. But I feel like I’m consciously contracting the bicep even if I’m using momentum or whatever. To me, what we’re ACTUALLY saying when we say ‘concentrate on this one muscle working’ is ‘concentrate on all the other muscles not working.’ So when I’m doing a curl where I want true isolation, my focus is on avoiding using leverages, swaying, swinging the weight up, engaging the shoulders/lats, etc. The natural tendency is to use as many muscles as possible to move a weight, because that’s efficient. So avoiding that natural tendency is what should require conscious effort.

The funny thing is I come from a bodybuilding background. Though I admit many pro bodybuilders would disagree with me, as you mentioned. I still don’t think it makes them intellectually correct. Pro’s usually train however feels good for them regardless of form, or convention and still get amazing results.
The MMC and poor body mechanics came mainly from Weider publications, ghost written accounts that didn’t actually come from the pro in focus. I fell for all the bullshit and followed it religiously for many years. In the internet age, you could see actual footage of these pro’s training and most of the time they don’t even train like how they say they do in the articles. Does it work, yes it does, but I felt it caused chronic pain, not just in myself but others as well.

When I started to train the movement, not the muscle my chronic pain was greatly alleviated, even disappeared in some areas. I didn’t notice any negative consequences regarding muscle growth which is my primary goal. In fact I got new results in the target areas despite not consciously trying to focus on contractions.

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