They say there's no fountain of youth. But a comprehensive new Harvard University study is the latest report to break down exactly how much extra time you can get yourself on this planet if you follow a small number of  positive life habits.

None of these habits will be a surprise, but the stunning part is how the Harvard researchers claim to be able to quantify exactly how much more time you'll likely live: specifically an extra 12.1 years for men, or an extra 14 years for the women.

Their research was published in April in the journal Circulation. Here's the research, the findings, the specific habits--and just how precious that extra decade-plus could be.

The research

Despite spending far more on medical care than any other country in the world, Americans have only the 31st highest life expectancy (79.3 years). In some states, it's as low as 71 or 72 years--about the same as in developing nations like Bangladesh.

(Here are all 50 states by life expectancy, if you're curious where yours ranks.)

So, Harvard researchers accessed the health histories of 44,354 men and 78,865 women, spanning roughly three decades, who had participated in two previous studies: the Health Professionals Follow-up Study and the Nurses' Health Study. 

Since more than 42,000 of the study participants had died by the time the researchers accessed the data, they could now correlate the degree to which people reported practicing health habits to their total life expectancy: the 12.1 and 14 extra years we referenced above.

So, what were the habits? Again, there are no real surprises, but perhaps seeing them laid out like this, specifically tied to a longer life, will motivate you to try to stick to them.

1. Don't smoke. 

If you smoke, quit. If you haven't started smoking, keep it that way. Other studies have shown that on average, if you smoke, you'll die seven years earlier than you otherwise would.

2. Maintain a low body mass index.

We've seen this one many times too. For example, if your waist measures more than 40 inches (men) or 35 inches (women), you need to lose belly fat fast in order to add years to your life. 

3. Work out for 30 minutes per day.

Again: We've seen it before. A short period of jogging each day, for example, can make your body seem nine years younger, according to another study.

4. Drink alcohol moderately.

Obviously, don't drink to excess. But other studies have found that drinking moderately improves health and longevity outcomes over not drinking at all. ("I have no explanation for it, but I do firmly believe that modest drinking improves longevity," is how the author of one recent study put it.) 

5. Maintain a healthy diet.

It's a bit difficult to define a healthy diet by Harvard's standards in this summary, but they describe it as having "a high diet quality score (upper 40 percent)." Of course, you probably already know what a healthy diet looks like. Start with foods that are high in antioxidants

It's worth noting that the study used age 50 as a benchmark, meaning that they looked at how long people could expect to live beyond that age, depending on whether they did or did not adhere to healthy habits.

It's not clear that this means that you can adopt the habits later in life and still get a similar health outcome. But it does suggest that no matter when you start focusing on your health, you'll likely have a measurable impact on the total length of your life. (See you at the gym!)