Three large studies, taken together, confirm that stress ages you, optimism extends your life, and self-talk works to help you achieve your goals and improve your performance.  None of these is astonishing, given the preponderance of evidence that has developed over the years, but taken together the studies suggest the importance of taking seriously the mental work of framing your life – and your work as a speaker or executive — in various ways that avoid doom and gloom and that focus on the positive – aka peak performance work, for those of us who live in the keynote speaking or executive communications worlds.

The first study looked at over 6,000 adults and found that stressors weaken your immune system over time and thus accelerate aging.  The effects can be combatted with good diet and exercise, but you probably already knew that.  We often can’t control the stressful events that life hands us, so it’s up to us to control what we can —  certainly the daily diet and exercise that can keep us feeling better, more in control, and less helpless in the face of difficulty, whether in organizational life or in our personal lives.

The second study followed 150,000 people for over a quarter century and found that being optimistic added about 4 years to your life.  The sample was large enough to eliminate the other effects due to diet and exercise and other lifestyle factors, leaving only the effect of optimism.  So just by thinking happy thoughts we can extend our lives, folks.  It’s the opposite of the old joke about cutting out one vice or another not really making you live longer – just seeming longer.  With optimism, presumably, you both feel better and live longer.

Finally, the self-improvement study looked at 44,000 people trying 3 different kinds of motivational techniques.  Self-talk came out first, followed closely by mental imagery (constructing visual scenes of success) and third by planning to act in a positive way.  Apparently, it works best to focus on either process or outcome, rather than self-instruction.  Say to yourself, “I will ace that speech,” or “I will remember to stand tall and exude confidence.”

Anyone who is seriously interested in peak performance issues in high-adrenaline endeavors like public speaking, or leadership, needs to understand what these studies – and many others like them – teach us.  Most of us, as we strive to get better at a high-adrenaline craft, will sooner or later face the gremlins of anxiety and psychological blocks to our advancement.  Yet while no one is surprised to see an Olympic skier readying herself by running over the route in her mind, it is a practice that so far has not carried over into public speaking and leadership as much as it should.

As a result, those gremlins hold more of us back more often and for longer than they need to.

In sports, the notion that you need to make allies of your mind and body in creating peak performance is well understood.  The idea is simple:  to imagine the ski run or the gymnastic routine or the weight-lifting sequence so that when it comes to actually doing it, you do it better.  Add to that a positive mantra, and you are good to go.

So pay attention to these studies, and get to work if you haven’t already.  To be sure, there are many questions that still need more answers, especially about imagery work.  For example, is it better to imagine your routine externally, like a movie, seeing yourself doing it, or internally, from your own perspective, seeing what you would see as you did it? Is it better to imagine the routine visually, forming images of the routine, or kinetically, feeling your muscles go through the routine? Or is some combination of the above the most effective? The research hints at the latter, but more needs to be done.

Further, is it better to imagine good outcomes, or to imagine yourself avoiding bad outcomes? The large studies I began with suggest optimism is best.  Is imagery and self-talk best for easing performance anxiety, or for focus — increasing your physical symptoms to be like game day? It appears that you need a bit of both, but it depends on the desired outcome.

None of these questions should prevent you from beginning today with optimism and self-talk to improve your general well-being and your specific life as a public speaker or an executive in a high-stakes role in a large organization, or a startup, or in politics.