Last week’s article ended this way: “And the well-timed ingestion of ‘straight’ caffeine can certainly increase the length and intensity of your workouts.”

While ending an article with such a general statement bothers me, I’ve learned to accept the limits of an 800-word column and write what could be called follow-up articles. So this column will specify what qualifies as “well-timed” — after clarifying the use of “straight.”

Most people associate that far more focused and slightly frenetic feeling that sipping a strong cup of coffee (especially on an empty stomach) creates with the caffeine it contains, but coffee and caffeine have somewhat different effects on your body. If you want to use either or both to better your health and fitness, you’ll benefit from knowing the differences.

In short, sensibly consuming coffee helps your health while sensibly ingesting caffeine “straight” allows for longer and tougher workouts.

The use of “straight” here means as an ingredient added to a beverage that contains no other reputed ergogenic elements, such as the taurine included in many energy drinks, and not from coffee or tea. Both beverages contain more than a thousand chemical compounds — including a few that mitigate caffeine’s effectiveness as an ergogenic aid.

Researchers have concluded, for instance, that the L-theanine in tea counteracts that ready-to-go feeling you get from caffeine. In fact, L-theanine relaxes you so effectively that it is sold as a dietary supplement to do just that.

While similar research on coffee might be less definitive, this much is known: when researchers inject some of the chemical compounds found in coffee into rats, they record a decrease rather than an increase heart rate and blood pressure, increases that inevitably occur in you when you consume “straight” caffeine.

These other chemical compounds, however, may very well enhance coffee’s ability (when used regularly and moderately) to protect your cardiovascular system, moderate your blood sugar levels, and reduce your risk of stroke, diabetes, kidney disease, dementia, multiple sclerosis, and certain forms of cancer — which is why the first half of today’s title reads “Coffee for health.”

For the second half of the title, “caffeine for workouts,” to be true, you need to do more than be sensible with the amount used (50 to 200 milligrams based on how your body reacts to it). You need to time your use of caffeine to get its maximum benefit.

While not everyone metabolizes caffeine at the same rate, most record peak blood levels of caffeine within 45 to 60 minutes of consuming it. Because of this, you might decide to add a caffeinated “on-the-go packet” of Crystal Light or a similar brand to 16 ounces of water and drink it about an hour before a workout.

That plan works well if your workout lasts less than 70 minutes.

But here’s what many don’t realize about caffeine: if given proper time, it encourages the muscles to use fat as fuel at a time when the carbs that have become glycogen are your body’s preferred fuel. But it takes about three hours for caffeine to have this effect.

It also normally takes about 70 to 90 minutes of moderate-to-intense exercise for the body to switch from using less and less glycogen and more and more stored fat — unless you’ve consumed caffeine three hours prior to the start. Then your use of glycogen as fuel in the first 15 minutes of a workout decreases by up to 50 percent.

And is replaced by the burning of stored fat.

Not only does this allow you to work out longer and harder, but when done regularly it also reduces your percentage of body fat.

So if you plan to exercise after a typical work day, consider adding some sort of on-the-go drink mix to water and drinking it just before or during your afternoon break. And if you need that kick-in-the-pants feel of caffeine as a mental boost just before or during an especially long or intense workout, use about half of an on-the-go packet —- and save the other half to use with the food you eat afterwards.

Do so because a bit of caffeine in your bloodstream allows the muscle cells to restock more glycogen after a hard workout. In fact, a 2005 study performed at the University of Birmingham in England found that glycogen-depleted athletes who consumed caffeine along with their post-workout carbohydrates absorbed 26 percent more fuel into their muscle cells.

What needs to be considered here, however, is how you personally tolerate caffeine. Some who are highly sensitive might find that their quality of sleep gets compromised by ingesting even 30 milligrams of caffeine along with supper.

But for every person like that, there are probably five who can enjoy a cup of coffee after supper and feel no aftereffects.