The research, which began in the 1960s, evolved into a longitudinal study in the 1970s to better understand cardiovascular diseases. The work was extended through 2014 as a longitudinal study, focusing in part on how mid-life risk factors can impact quality of life and well-being in old age.

The new findings are a follow-up to the Helsinki Businessmen Study , research that for decades has followed 1,222 male executives born between 1919 and 1934. Each had at least one risk factor for heart disease (for example, the men smoked, were overweight, or had high blood pressure or high cholesterol).

And if you think your spin classes and kombucha habit will make up for postponing that dream cruise and save you from your jam-packed, hard driving life, think again. An improved, healthier lifestyle will not compensate for working too hard and not taking your holidays, University of Helsinki professor Timo Strandberg said Tuesday at the annual European Society of Cardiology (ESC) Congress. "Vacations can be a good way to relieve stress."

Thinking about skipping those vacation days? Don't. One of the longest follow-up studies in the world finds vacations can actually prolong your life.

For the study, the men were randomly split into two groups. In one, a control, men lived their lives as they always did and did not meet with the study's investigators. Men in the other group, an intervention group, were given advice on how to improve their health. These men were asked to exercise, improve their diets, reach a healthy weight or stop smoking.

Strandberg found that the men who improved their lifestyles had a higher mortality rate if they shortchanged their vacations. At the study's 15-year check-in, those in the intervention group had higher mortality rates than those in the control group. The culprit? Working too hard, not sleeping enough and not taking enough vacation.

In fact, those in the intervention group, the ones with improved and healthier lifestyles, had a 37 percent higher chance of dying between 1974 and 2004 if they'd taken vacations lasting less than three weeks when compared to those who took vacations lasting three weeks or more.

After 2004, mortality rates for men in both groups were the same. (By then, the men had reached their 80s and 90s.)

While dramatic, this new research won't likely impact most Americans' vacation habits. Most American workers don't get that many paid days to begin with. Younger workers might not have the work experience to hit the magic three weeks of vacation noted in the study. In fact, the Bureau of Labor Statistics says the average worker has logged 20 years of experience before earning 20 paid days or more in some positions.

Even if they do have the time, many workers feel they can't take it. Americans have put off vacation because they feel they have too much work to do and too many family obligations. Many feel a vacation is simply a luxury they can't afford.

Given that experts find that vacation can help you be more productive when you return to work, maybe it's time to put in that request for a few days off.

Like this story? Like CNBC Make It on Facebook!

Don't miss: