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Cardio Types and Body's Reaction

Hi! I have a strange question. I do the 10k KB swing programme as my gym does not have many plates (110kg total), a squat rack or a place to deadlift really. I remember when I did this programme back in March or April 2020, I was dying by the end of it and that was with a 16kg (the only size KB I had at home and it was lockdown). I finished the 10k swing programme with the 16kg in January (did it in 3 weeks going pretty much everyday) and then started on the 20kg, the heaviest kettlebell in the gym, and I go pretty much everyday here too. I also swim.

My question is, when I swim, my heart pounds but my breathing isn’t that heavy. With the kettlebell, my lungs at the end of the 5th set are sometimes on fire but my heart never feels overly fast. Why would this be when they are both cardio and what might it be indicative of?

Thanks and sorry for the long winded question

That’s a good question, and similar to what I’ve experienced and wondered. Some exercises make me pan and gasp but don’t elevate my heart rate a lot, but other exercises make my heart pound without affecting my breathing much. I have no idea why. Maybe @j4gga2 @whang or @Frank_C know or can tag someone else who does.

Appreciate the tag, but I’m not so sure. My guess is because they’re completely different exercises. In swimming, you use your whole body, and you’re trained to breathe periodically in an efficient manner. Not sure how you breathe during kettlebell swings. Also, I think the only reliable way to compare the heart part is if you actually know your heart rate during swims and during KB swings.

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Yeah, I’m not sure either. Kettlebell swings also use the whole body, whether for locomotion or stabilization, and swimming is movement against resistance, albeit less localized resistance than a kettlebell.

I feel KB swings are not as globally demanding as swimming though. Correct me if I’m wrong, but I think swings are mostly a hip hinge with isometric hold on the forearms.

For sets of 10 to 20, definitely. When doing 500 per day and spending 20 to 40 minutes per session, KB swings may be closer to swimming. I’ve never done the 10,000 KB swing challenge, so I don’t really know how it compares to traditional, moving-the-body-through-space cardio.

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I’ve never done the challenge either. @flappinit did though

Oh and another theory… in swimming, relative humidity is really high since you’re in a pool of water, so the air you breathe is moist. In KB swings, you could be breathing cold dry air, which will make it feel like it’s harder to breathe.

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True, I hadn’t considered humidity and its effects. However, I live in a very dry climate, but I’ve experienced the heart rate/breathing dichotomy apart from the pool.

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Ohhh. Interesting.

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Thanks guys! A lot of replies and I am glad to see I am not the only one who does not know. On the humidity theory - the pool is an outdoor pool (albeit on/right next to the sea) and the gym in theory has AC on but in reality they don’t always turn it on. I am in a tropical country. I am not sure this is necessarily the answer but who knows. On the 10k challenge - 500 swings and 30 weighted chin-ups is definitely a full body workout. My swimming breathing technique is not great to be honest, either.

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One is cardio: the other is conditioning. Swimming the former: swings the latter.

The swimming is non-stop movement. You don’t move your right side, pause, then move your left side, or else you will pause and drown. Similar to running: the body is in motion the entire time. This is going to result in a sustained heartbeat/tempo.

The kettlebell swing has no eccentric phase (unless you’re performing them VERY weirdly), making it a series of intervals. You exert, rest, exert, rest, etc. This is going to have a different effect on heart rate.

Breathing is in a similar way. Swimming can be done at a leisurely pace. I don’t swim, but when I run, if I want to keep my pace relaxed, I ensure that I ONLY breathe through my nose the entire time. In doing so, I can’t push myself to the point of gasping for air, so my lungs don’t burn, but my heart rate is certainly elevated.

It’s far easier to push the swings in a stupidly hard direction and get the lungs burning, especially with the interval nature of the exercise.


What he said ^^^

It’s the difference in length of exertion. During the swings, you have a recovery period. Even if it’s short, it’s longer than the non-existent recovery periods of swimming.

And I’d be interested to see your HR on both. I bet your HR is getting high during swings, too. Perhaps you just can’t notice it due to the gasping for air part.


In addition to what has been said,

Kettlebell swings require the contraction of a massive proportion of total muscle mass. When muscles contract their capillaries are constricted to the point that the muscle no longer receives oxygen and can no longer dispell CO2 into the bloodstream. As such, kettlebell swings require strong laboured breathing to make up for the times in which muscles cannot participate in gas exchange. Moreover, swings require IAP to stabilise the spine, which requires one to inhale and hold their breath. This forces you to couple your exhales to the concentric of a swing and inhales to the kettlebell recovery portion

Swimming, on the other hand, is a very relaxed movement, and therefore does not restrict gas exchange to muscles to the same extent. It also doesn’t require IAP.


Some great answers and a lot to think on/research here. Thanks for the responses!

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I’m late to the party, but I dont really think it has much to do with the exercise as it does with you the individual, and what you are or aren’t doing.

Swimming tears me up more than other form of cardio/conditioning. I used to swim competitively for four years in highschool, and I still swim currently. A bit less than I used to but you get it.

It comes down to technique and breathing really. Are you swimming laps? Do you do mostly freestyle? Butterfly? Breast stroke? Do you keep your head above the water most times? When you’ve reached the end of the lap do you stop, kick turn underwater, or just turn and kick off from the pool wall? Does most of your power come from your legs or your arms? Overall do you swim soft or hard? Can you dish out a considerable amount of meters when swimming?

I ask because it can kind of get skewed if you’re an experienced swimmer. You noted that you’re progressing with swings, but with the addition of a new weight it’s prompting you to have to adapt. Is there any facet of your swimming that’s having to cause you to have to adapt even more? If not, I think it would be safe to say you’re just good at swimming now, in which it’s fairly easy for your heart rate and breathing to return to normal.

I wouldn’t completely agree with this just because there are a multitude of ways where one can easily become conditioning, and the other cardio. And so on.

Not saying anyone is wrong though.

Again just to focus on this part of what you said, I think it comes down to how fast you’re going and what you’re doing specifically. I’ve noticed a considerable change just by where I’m keeping my head. If I’m keeping my head solely above the water, it’s…idk easier to catch my breath. If I’m doing…say freestyle, really going in, and moving my head in that back to back fashion that’s gonna cause me to have to have to hold my breath after one whole cycle of strokes, by the time I finish however many meters my chest is on fire.

This is just my own speculation…but essentially you can kind of manipulate that same breathing with something like KBs. Concerning how you breath at least. If you’ve got some rhythm of breathing down I think it’ll produce that same feeling regardless. Swimming or swinging.

As far as intervals go I think they’re more similar than they are different. This is more or less a rhetorical question. When you swim, would you say you’re keeping the exact same pace as when you started once you’re nearly done? Nah. Not really. You’re gonna slow down. Of course you can’t full on stop when swimming, but you can still reach a point where your body can get back to stasis. Kinda the same with KBs yeah? You’ll slow down and rest as fatigue sets in. Say you push it though…your heart and breathing will respond accordingly. Say you try push the pace while swimming…well…same thing with your heart rate and breathing.

I’m not throwing shade on anyone here. Also not saying you’re doing anything wrong. Just saying you’re doing things…different I suppose.

Again… this is my own speculation. The mention of swimming also got me excited since I don’t see many other swimmers on here.

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