The time it takes for a guy to enlarge his penis naturally with exercise varies significantly. Some men decide only to exercise their manhood for a few minutes a day, a couple of times a week. While others engage in penile exercises for several hours a day. I would suggest the later is not the best way to make your penis bigger and can actually be extremely dangerous.
Many guys don't have enough time in their day to exercise on a regular basis. So they have a sporadic routine with no real consistency. However, this type of routine has worked for some to enlarge their penis naturally. But i must stress irregular sessions may not work for you. At the end of the day it is your decision as to how often you exercise to make your penis bigger.
When you first start an exercise routine, you should have an extremely light and easy workout to enlarge your penis naturally. You want to slowly build up and only add exercises or additional time to your workout when you feel comfortable. Always keep in mind that exercising your manhood too much can have a detrimental effect.
The gains that you see will again vary from person to person. The largest ever reported gains from penile exercising was for a man who started off with a member that was 4.5 inches in length and 3.5 inches in girth. After 2 years of exercising, he eventually ended up with a manhood that was 8 inches long and had a girth of 6 inches. It terms of volume, he had managed to make his penis 5 times bigger than it originally was.
There have been numerous occurrences and stories of men who have exercised to enlarge their penis naturally and seen gains of 3, 4 and even 5 inches. Although it's important to remember, that we are not all so lucky, genetically able or dedicated. In truth the average gains you can expect from following a reputable penile exercise program would be 1 inch in length and 0.5 inches in girth within a 2-3 month period. If you wish to exercise to make your penis bigger, this 2-3 month gain translates to a 41% increase in penis volume. That is just under half a size bigger than when you first started exercising!