So, I heard cardio can make you flabby?

When you are in calorie deficit you lose both muscle mass and fat. This is true when you do cardio only and weight train. However.... when you do only cardio you lose more muscle mass than if you were on a solid weight training program. Cardio only means you essentially become a smaller version of your previous self. For example, you can be 70kg and be 30% body fat and be 55kg and still be 30% body fat. This is how people become skinny-fat... they may be small but their body composition still has a large percentage of fat.

When you strength train while eating a calorie deficit you maintain as much muscle mass as you can. What this means is that you reduce the rate of muscle loss. You can only affect two things within your body... the amount of muscle you have and the amount of fat. Looking "toned" is a result of building/maintaining muscle mass while reducing your body fat percentage. Basically using the above example.... if you started at 70kg and 30% fat and you lifted weights while dieting to 55kg, your body fat percentage may drop to say 20% and your figure would be significantly better than the skinny-fat person of the same weight.

In 30 years as an exercise physiologist, having worked with thousands of people, I have seen plenty of people who were BORN skinny fat. I can't remember working with anyone who BECAME skinny fat from doing cardio.

I did. I'm stoked to be the smaller version of my fatter self (size 18 to size 4), but that's exactly what I am.
OK. I have much less of a tire around my middle, but I have lots of flab just llike I did 50 lbs ago.

I have no clue if that's true or not, but I would suggest buying a resistance band, I have one and it really helps to build up my muscle, I don't go to a gym and have hand weights too, but I really like the resistance band though

I've heard that more than 40 straight minutes of cardio can actually destroy muscle mass if you don't weight train along with it. So, question one: is this really true?

Absolutely not true. Otherwise any sportsman doing a cardio intense, long duration sport like soccer, tennis, rugby, distance running, cycling would be flabby.

Not a very good example, most athletes are not eating at a deficit for long periods of time.

You are reading something into this that isn't in the OP. Not everyone on here is eating at a deficit and a calorific deficit wasn't mentioned. Being inactive is the primary cause of people being flabby not doing (and I quote) "40 straight minutes of cardio".

When you are in calorie deficit you lose both muscle mass and fat. This is true when you do cardio only and weight train. However.... when you do only cardio you lose more muscle mass than if you were on a solid weight training program. Cardio only means you essentially become a smaller version of your previous self. For example, you can be 70kg and be 30% body fat and be 55kg and still be 30% body fat. This is how people become skinny-fat... they may be small but their body composition still has a large percentage of fat.

When you strength train while eating a calorie deficit you maintain as much muscle mass as you can. What this means is that you reduce the rate of muscle loss. You can only affect two things within your body... the amount of muscle you have and the amount of fat. Looking "toned" is a result of building/maintaining muscle mass while reducing your body fat percentage. Basically using the above example.... if you started at 70kg and 30% fat and you lifted weights while dieting to 55kg, your body fat percentage may drop to say 20% and your figure would be significantly better than the skinny-fat person of the same weight.

In 30 years as an exercise physiologist, having worked with thousands of people, I have seen plenty of people who were BORN skinny fat. I can't remember working with anyone who BECAME skinny fat from doing cardio.

Oh please, babies aren't born skinny-fat. Is that what you tell your clients? People become fat the usual way (being sedentary and eating a surplus) such that their body fat percentage increases (hello obesity). Then when people decide to "lose weight" through diet/cardio they get smaller, but often still retain a higher percentage of body fat.

The key message is that you can change the ratio of muscle in your body and achieve a leaner look. One thing for sure you will not achieve this through cardio and diet alone. You will maximse your sucess if you make strength training a priority in your routine.

People are born with specific body types--genetically determined frame sizes, patterns of body fat, etc. Surely you know this? You must have noticed that people sitting next to you look differently than you.

Maintaining a somewhat higher percentage of fat does not make you "skinny fat". Someone who loses a lot of weight through cardio and diet, or even cardio alone, may not have the same level of muscle mass as someone who lifts, but, again, that does not make them "skinny fat".

My problem is not with strength training--there is no disagreement about its benefits -- but with the obsession that many lifters have with proselytizing their personal preference as the "one truth faith" and the promiscuous and inaccurate use of the term "skinny fat".

"Skinny fat" has become the new "starvation mode" cliche and it has led to such bizarre and laughably ridiculous statements such as "cardio can make you flabby" and "cardio burns muscle", and the even more ridiculous and absurd assertion made earlier that someone could lose 15kg of weight and still have the same % body fat as when they started, which would not only require a loss of over 10kg of lean mass, but would take the the person down to a level of fat-free mass that is almost never seen in someone unless they are born with a certain body type.