Or should I say, how long does it take to wear off? I drink coffee on and off all day. I also enjoy several double shot mochas throughout the week (got my own cappacino maker). I have noticed sometimes my RHR is around 48-52bpm. And, sometimes it seems to be up around 60bpm. I can only assume my caffeine intake is what does this.
After consuming coffee regularly, how long does it generally take for it to wear off so you get an accurate RHR reading?

The caffeine doesn't seem to effect me very much. I can drink cups of coffee and then go to sleep five minutes later.

Not sure how it affects my RHR, I have never drank coffee with a HRM on. I'm sure all the cream and sugar my dad puts in his coffee is making his heart race...

Personally, I like black coffee

I've never checked my heart rate, but I do use caffeine on a regular basis; mainly before workouts and excercise. Usually it seems to kick in after probably 20 minutes and I go down in about two hours. This is just what I feel happen to me, not exactly what happens to my body, but in my head.

I actually hate caffeine because it is so addicting. You said you sip all day long, try going a day without any, you'll probably get a headache and just feel down all day. This is why I try to only use it before workouts. You get a much bigger effect from it as well, if you use it sparingly that is.

I almost never drink coffee and I no effect from it. I do enjoy a double shot before a race though, seems to help me... as the double energy gel too..

Too much makes me hyper. If I drink it much past noon, I may not sleep well that night. It affects different people differently. I limit mine as I enjoy a more relaxed way of living.

Like many addictive drugs, the more you take, the more it takes to get the affect up to a point. A friend of mine who normally doesn't get much almost hyperventillated when he got a big jolt.

The good news is that it does improve mental performance in moderate amounts and there seems to be no negative impact on health, again in moderate amounts.

Al

From what I understand, RHR is best measured in the morning before getting out of bed. Runners recommend logging this daily. A sudden sustained increase is a sign of over-training.

It depends largely on the individual. Some people metabolize it faster than others. Generally the minimum would be about 3 hours if I remember correctly.

I've seen a study that claimed that maximum mental acuity is obtained after 2 ordinary sized mugs of brewed coffee; anything beyond that only increases the negative effects, e.g. 'jitteryness'. The effect on alertness is said to last up to 8 hours. None of this may matter to the effects that cyclists are seeking to attain....

There is a benefit claimed for cyclist. Caffeine increases the amount of fat in the bloodstream which is available for energy. This is supposed to reduce the need for carbs or blood sugar for the well trained athlete. That's why you'll see some gells with caffeine added.

The problem with most claimes like this is they never tell you how much it increases the blood fat or how much less blood sugar you need. The devil is in the details like is the difference worth the bother.

Al

if i have a cup of coffee at noon, i find it very difficult to fall asleep before 2:00 am. i have a very high metabolism, i suppose that may have something to do with it.

when i was an architecture student, i would take Vitamin B12 supplements to stay awake. i would use this as a natural caffeine substitute (the headaches associated with caffeine withdrawals are unbearable). does anyone else use this?

I'm what you call a coffee addict. i can't start my day without some strong Turkish coffee. Yet, it's been shown that the effect of coffeine is psychologicay because it really kicks in about an hour after coffee was consumed. There are different ways of gettin caffein faster into the system, but here I'm talking about the good old coffee. In any event, I can have very strong coffee before going to bed and fall asleep. so coffee serves me only in psychological terms. It does have some small effects,but the more you drink it the more resistant you are to its effects. The best thing is to keep the coffee consumption low. Drink tea. It comes with coffeine and with many antioxidants that are much healthier.

Normal coffee or tea doesn't do much to me, but having a Starbucks double shot espresso (6 oz can) will easily keep me awake for 24 hours!

Usually, I have two really big cups of the Italian coffee I brought back with me from Italy. That coffee usually takes me about 3 hours to begin to wear off.

Koffee

I drink coffee all morning with my last cup about 11 a.m. I ride on weekends and drink two big mugs of coffee before my pre-ride fruit and protein smoothie. I have no idea if it helps my riding, but it's the way I like to start each day. I don't have jitters or other side effects, or at least none that I know of.

Caffeine Levels in coffee, et al . . .

COFFEE CAFFEINE (mg)
Brewed, drip method (6 oz.) 115
Brewed, percolator method (6 oz.) 80
Instant, one rounded teaspoon 65
Flavored, regular & sugar-free (6 oz.) 25-75
Espresso (1.5 to 2 oz.) 100
Decaffeinated (6 oz.) 2
Decaffeinated Espresso (6 oz.) 5

OTHER CAFFEINE (mg)
Tea, brewed (6 oz.) 35
Mountain Dew (12 oz.) 55
Baking chocolate, unsweetened (1 oz.) 60
Chocolate ice cream (1/2 cup) 2
Excedrin (per tablet) 65
Excedrin PM (per tablet) 0
No Doz, regular (per tablet) 100
No Doz, maximum (per tablet) 200

Source: Men's Fitness June 2000

Dunkin' Donuts and Starbucks coffee are over 300 mg per cup.

Koffee

- most excellent post... i'm developing a small, lightweight kit that will include a jezva, 50g alcohol stove, water, sugar, and talcum-ground java to make turkish coffee on the trail!

(pics to follow in the next week)

- the stove i'm going to use is the penny alcohol stove

Two cans of Pepsi in the morning and I am good to sleep by 8:00 PM. Two cans of Jolt Cola in the afternoon and I only get 2-4 hours of sleep.

I've read a ton of reports on this over the decades, and the only thing everyone seems to agree on is that the number of hours caffeine affects any given individual increases with the age of that individual.

After that, all other variables (how long X amount affects you, how much you should drink, whether coffee is good or bad for you, whether caffeine is good or bad for you) seem to differ either by each body's highly individual metabolism, or depending on which study you're reading about (and wish to believe).

Coffee does nothing for me. I once had a Starbucks Quad-shot Cappuccino after a few hours of sleep, and it got me going for a couple of hours but nothing more after that. I'm 20 years old if that describes anything...

I've switched to tea instead for better taste and because I just don't like coffee much.

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