Dr. Sanjay Gupta: A jolt for java lovers?

CNN's Dr. Sanjay Gupta

(CNN) -- Many people rely on a cup of java in the morning to get going. But a new study finds that regular coffee drinkers get less of a energy boost from caffeine than those who only occasionally have a sip.

Dr. Sanjay Gupta, CNN's medical correspondent, joined CNN anchor Arthel Neville for a sort of coffee klatch -- minus the caffeine.

NEVILLE: Did you have coffee, first of all?

GUPTA: I haven't had my coffee. I'm not much of a coffee drinker. I was actually going to ask you the same thing because I know these are some early morning hours for you. How are you doing?

NEVILLE: No coffee, [I'm] struggling a little bit, but no coffee. But you know what -- for those of [us who] don't drink coffee so much, we'll clearly get a bigger boost from caffeine because our tolerance level is lower, right?

GUPTA: That's exactly right. So it's a little bit of vindication for the noncoffee drinkers amongst us. Certainly, there is a journal study that came out, and they actually looked at this issue. They looked at the people who drank coffee regularly and people who didn't drink it. They actually gave everyone a dose of caffeine or the equivalent to a cup of coffee.

What they found are that people who are regular coffee drinkers got less of a jolt at it, specifically in terms of exercise tolerance. They could ride a bike, for example, 23, 24 minutes without it and about 28 minutes with coffee. Those are regular coffee drinkers.

People who don't drink coffee had about a six or seven-minute extra burst of energy from the coffee. Certainly it points out -- I guess not unexpectedly -- that if you're not a regular coffee drinker, and you occasionally dip into the caffeine pool, you're going to get a much bigger kick out of it.

NEVILLE: What about those other drinks like Red Bull and other caffeinated drinks? Which ones have the most caffeine?

GUPTA: Funny you should ask. I actually have a whole list of them right here. And I think we've got some numbers to show you as well. We actually did some research on this.

Coffee, for example, [has] 85 milligrams; this is typical eight-ounce cup. Red Bull, 80 milligrams. ... Espresso is probably your best bang for your buck, 40 milligrams of caffeine in just one ounce. Ice tea, 25. Coke about the same, 24. And don't forget chocolate as well has caffeine in it. One ounce [has] about six grams of caffeine as well. So a lot of sources of caffeine there.

NEVILLE: If I had espresso, I would be just -- they would have to contain me, strap me down with some espresso.

GUPTA: Makes me really jittery, too.

NEVILLE: It does. Now aside from people like me, who else should stay away from coffee?

GUPTA: It is important to remember that coffee -- caffeine specifically -- really is a stimulant. It stimulates all sorts of things in your body. People typically associate it with increased alertness, maybe a little increased energy. But it also increases your blood pressure, increases your heart rate and those sorts of things. People who have troubles with their heart, pregnant women have oftentimes in the past been told to cut down on the amount of caffeine.

And don't forget that caffeine is a diuretic. It will actually cause you to lose water. If you're drinking coffee, you're probably dehydrating yourself. You need to supplement [it] with extra fluids. Important things to keep in mind if you're a big coffee drinker.

NEVILLE: What about alternatives? I know sometimes because, as I said, that caffeine is not necessarily the best thing for me, I take ginseng sometimes to get a little bit of that same jolt, which also has health benefits to it as well.

GUPTA: That's right. Caffeine is a stimulant, and there are all sorts of different stimulants out there. Caffeine, not to get too science-y, but it actually improves the way your cells metabolize things so it makes your body really efficient. And that's why people sort of like caffeine.

But there are other things out there that do that, that may not have some of the negative side effects of caffeine, again such things as increasing your heart rate, blood pressure, things like that. Ginseng is a good example as any Arthel.