Can strengthening core improve vocal abilities?

I apologize for the unusual question, but I've been doing some core strength training (transverse abdominus/rectus abdominus) and have noticed some improvements in my vocal quality recently. I am unsure if my improvement has been caused by my recent core strengthening though. If so, I will happily continue progressing those particular exersizes I've been working on! 

Also, can practicing holding your breath improve vocal breathing quality? I heard that it is beneficial to the diapham once, but that it is actually quite harmful to your health from another source.

Thanks!!

Great question, Jared! Speaking from my own experience: yes, core work and cardio can definitely increase your lung capacity and your ability to engage the body when you sing. I've noticed significant improvement in breath support and vocal quality when I'm in the habit of exercising more intensely. Many singers (especially singer-dancers and musical theater performers) take up swimming to increase their lung capacity, which certainly involves holding your breath. However, I've also worked with swimmers who have a hard time not holding their breath when they sing, and it takes them a bit longer to learn how to use their air with a healthy level of resistance from the body. 

At the end of the day, I encourage you to do what works for you - whether or not it works for other singers. I can't speak to the overall health impact of holding your breath, but I can foresee some potential issues if you get into the habit of locking up completely (as opposed to gently suspending the breath and releasing slowly as you sing).