More muscles mean more fitness
Isolated training muscle groups can actually weaken muscles when it comes to use in a functional fashion or everyday life.
"It's not going to get you fit by any stretch of imagination," said Kris Morrill, fitness coach. "It is going to work on high pressure for you getting you a little bit bigger getting you leaner for the most part depending on how your diet is."
Instead of doing body part splits try a more comprehensive program. That will allow you to get stronger, leaner, and more well rounded. These compound movements work multiple major muscle groups.
To add intensity, test limits with weight or a race against the clock. For example, try five pull ups, ten pushups and 15 sit ups in a cycle for 20 minutes to see how many rounds you could get. This allows you to keep score and see improvements.