@Beau Skunky  
yes but she not mastered it yet, but she do master unicorn side, she to master the earth pony and Pegasus side if she want master the true power of the alicorn, this is why she a not win against starlight

@PonyPon  
Okay, so it doesn’t actually say “Earth Ponies get super-strength, and Alicorns do too.”
 
Applejack and the Honest to Goodness Switcheroo does say that Earth Ponies are super-strong, though, so that much is canon. (If you accept the chapter books as canon, of course.)
 
Considering that Alicorns get powerful magic from both Unicorns and Pegasi (remember that one time Luna turned a clear night sky to thundering storm clouds in a few seconds in Luna Eclipsed?), I don’t think it’s at all a stretch to say that “good strong heart” is meant in the Phar Lap sense - in that they have enormous, strong hearts that can pump lots of blood and let them move more powerfully.

@Sora2455  
The ‘good, strong, heart’ line?

@Sora2455  
Really? Interesting. I believe “Word of Faust” even says that alicorns have earth pony strength & stamina too.

@Beau Skunky  
There’s a statement to this exact effect in the first chapter of Twilight Sparkle and the Crystal Heart Spell

Power of love.

Alicorns have wings, and magic horns, so it’s easy to assume that they have earth pony strength & stamina too. They’re like a combination of all three pony races.
 
Boy, Twilight must be buff!

Why did this double post?

@Napsack  

What about the bandage she had on her hoof in her next appearance? Mac could hurt her! And we don’t even know what it was that hurt him before Applebuck Season.

I guess love (or at least love poisons) make ponies stronger :/

@Legioner8  
Technically that’s still carrying a cake.

@MadVillan  
No, she’ll just eat it.

So she can pull a house, big deal. The real question is can she carry a cake?
 

@Darth Prime  
That’s… plausible, I suppose, but the comic doesn’t seem to show anything that would confirm or deny that interpretation, and Luna does drag Big Mac around effortlessly later in the comic…

I don’t think that was actually Celestia I always thought that that was one of those arm wrestling arcade machines.