Efficiency and intensity are secondary to intensity. It's better to do something 7 days a week without too much efficiency and intensity than do it 2 times a week with perfect efficiency and intensity.
One factor that I don't often talk about regarding consistency is the factor of luck. Luck plays a massive role in success and almost all successful people had a "luck moment" that helped them spiral up the success ladder in their respective fields.
Most people consider these successful men and women "lucky", which they are, but luck is not a random factor, it's directly proportional to your ability to be consistent.
The longer you stick in there and stay consistent the more chance you have of getting lucky. If you're in business and consistently taking actions to grow, you'll eventually hit a jackpot and find just the right client, partner or opportunity to surge in growth.
Even Mark Cuban says that if he had just waited a few more days to sell Broadcast.com to Yahoo! he might not have been a billionaire today. We all get lucky breaks, those who are consistent just get more.
So remember that even if things are going slow, as-long as you can clearly see a steady weekly or monthly improvement you're growing up, growth is almost always exponential and you're guaranteed to eventually get lucky just from the random variability life offers.
Consistency is everything, it's the root of all achievement, treat with respect and you'll get everything you've ever wanted in any field you apply it long-term. Now go and choose your consistency habits! You'll thank yourself in 12 months.