from uncomfortable to hard

Take a workout you do find easy and making it very hard can be just a few simple tweaks.  Change is a good friend for muscles.  Your body adapts quickly to changes in tempo, resistance, method, etc.

A favorite crossfit workout of mine is called "Cindy":

max rounds in 20 min of:
5 pullups
10 pushups
15 squats

I've reached 28 rounds on this one. Not saying that was "easy" just that I'm comfortable with the setup.  That means it's time for change!!  So I grabbed my lunchtime crew (I now have two separate classes - one during lunch MWF and one in the evenings M and Th) and tried this with them.

Max rounds in 20 min of:
5 weighted pullups (1x30# dumbbell)
10 diamond pushups
15 split jumps (count total jumps not each leg)

---that was a "gasper".  I only got to 14 rounds.  Actually a little disappointing for me but it felt good.

My crew did an easier version perhaps you would be interested.

Max rounds in 20 min of:
3 weighted pullups (1x30# dumbbell) NEGATIVE PORTION ONLY (partner assisted going up)
10 diamond pushups
15 lunges (total steps, not each leg)

Take care friends!
Brian