LiveStrong reports that The Coffee Science Information Centre (a place that’s probably my own personal Disneyland) has found that 100 to 200 mg of caffeine definitely has an impact on mental alertness. To help you visualise, one large cup of coffee from a coffee shop contains about 330 mg. A cup of instant coffee is 148 mg, putting you smack dab in the zone. Overdoing it, however, doesn’t make you even more alert — it’ll just increase your anxiety levels.
Of course, coffee can only go so far. When alcohol is involved, ending a wild night with a cup will help you be a little more alert, but it won’t counteract the effects of the booze. So proceed with caution.
