Really hard question, I'm not sure. But I switched from one 40 minut + one 30 minut stretching some time ago. To: 20 min x 3 times per day.
Only 16 days from 5“ to 5,4" is that normal? 😳
Okey.
Congratulations 👌
Congratulations on the gains. You have proven that your current routine is working, so stick with it for now. I would suggest that you measure again in 6-8 weeks to see if you are still profiting from what you are currently doing. I predict that you still have at least a half inch or so of fairly easy gains. When gains slow down, the ruler will confirm it, and at that point you will either need to increase the intensity, or time under traction, or both, in order to see results. You are on the right track. Again, congratulations!
The reason I say that, is because 1 inch of newbie gains is fairly common. A lot of guys reach the one inch mark. But I cannot know for sure, every guy is different, so there are no guarantees. Statistically speaking, the odds of you reaching 6" within the next few months or so are very much in your favor. The so-called easy gains happen when you first start out, within the first six months. After that, it becomes more of a challenge, you will need to refine your routine, but it is absolutely doable provided you have the discipline to stay in the game and do what is required to continue to see results. I have not helped you at all. You did it all yourself.
I'm going to get to 8" in the end, so 6" will be soon.
