I don't know for sure but it looks like one of the factors may very well be body type. She is more muscular with the legs and lower body but certainly does have muscle in the upper body. I would also think that she has a lot of cardio involved when she is performing because of all the dancing that she has to do.
Body type --- Somatotype body type is the base to work from. You are right! Of course there is tons of cardio as she stated during
the clip. I like her body language when she got questioned about sugar consumption. I reserve the right to not believe she
threat herself with all those pizza now that she is growing up!
You also have to take into account how young she was in those photos... she's not that thin anymore but still muscular. I still think that women bulking up is a bit of a myth due to our hormone levels; sure, there will be some who do but most won't. I thought I would based on my bone structure and body type but the opposite has happened. Whatever works, I guess!
It is definitely a myth!!! God knows how many articles have been around aiming to encourage ladies to lift heavier. Now that
this study sheds some light on strength training, It will be interesting to see if the 5x5 Nia trend will decline!!!
I doubt it, for the sake of fighting emotional obsession about expanding to hulk incredible size!!
The truth is pure strength
on 5x5 format put more stress on joints --- which is not good news for our health!!! More risks of injuries.
Now before I get off my soapbox, I will add an interestingQ&A from reputable source.
Source --- Fitness Rx June 2016
Q&A from a Fitness expert – Gunnar Peterson
"Q: What do you think about weighted oblique work? I have heard some say that it can add Bulk.
A: Let’s address the “adding bulk” part. That’s actually humorous and I’m not talking about your upper arm. “Adding bulk” is a lifestyle, not an exercise. It would take well-timed calories above and beyond what you are burning as well as adequate rest and recovery and a number of other factors to add bulk in one area with one exercise. Whew, glad I cleared that up.
Regarding the weighted oblique work, I think you are fine if you keep your rep range high- 15 to 25. The muscles need to work, and throwing in a purposeful frontal plane move adds some variety- and I’m all for that. You won’t build blocky refrigerator body unless you keep opening that blocky refrigerator door".