Concept2 Forum

I see a lot of discussion RE: fasted workouts. How much difference does it actually make? (other than it more or less forces you to row first thing in the morning)

Whats the definition of a "Fasted Workout" ?

Personally if I intend to row "Hard" then don't eat about 2 hours before the row at least. Pretty sure if you were up at 5:30am and OTW by 6:00am you wouldn't be eating first. Anything in liquid form is different, water or an energy drink helps rather than the effects of solid food have in slowing you down.

It is simply ridiculous to talk about fasting and endurance athletics. What does the body run on? Air. Of course, one cannot have a full stomach and then exercise. For one thing, the diaphragm is affected. If one does not eat 2 hrs before exercise, that is not fasting. That is just common sense. When I see someone say they had a "fasted" workout, all I can do shake my head. Do we have to hear about what hour everyone eats to see their training. What's next?

Well, when I do cardio in the morning I haven't eaten for 12 hours, so that is getting close to being fasted. But those sessions, for me, are low intensity sessions. Others are able to do much more intense sessions.

I would consider training in the morning, having not eaten since the night before to be fasted training.

Basically muscle glycogen is going to be as low then as it is possible to get - unless you deliberately fast 24 hours or so.

Training aerobically for a reasonable amount of time shouldn't be affected by this - in fact I find if training first thing in the am goes better if fasted - with just water, as opposed to even a sports drink beforehand.

In my experience I can row/run/lift and swing kettlebells for an hour or so this way no problem.

AT training, hard intervals and racing (and heavy weight training) is going to need more muscle glycogen or you're going to tap out fairly quickly - or at least not be able to go as hard or heavy as possible, unless you specifically train yourself for it.

Cyclingman1 wrote:It is simply ridiculous to talk about fasting and endurance athletics. What does the body run on? Air. Of course, one cannot have a full stomach and then exercise. For one thing, the diaphragm is affected. If one does not eat 2 hrs before exercise, that is not fasting. That is just common sense. When I see someone say they had a "fasted" workout, all I can do shake my head. Do we have to hear about what hour everyone eats to see their training. What's next?

Mmm, Chris Froome does not eat before his training, he starts eating during his ride......

But alla, he is a nobody ofcourse

Coming over from cycling the reason people did fasted training was so that they were teaching their body to burn a higher proportion of fat at a given effort level and to stimulate bio-genesis of muscle capillirisation. On this last point, I've don't know how effective it is but I suspect most of us aren't maxing (in terms of time spent) out on our aerobic potential through "conventional" training anyway....

I use to always encourage clients to eat smart before exercise and to do so well in advance so as the body can digest what you have eaten.. and I stuck by this for years.

BUT, recently I have been changing things for myself whereby I eat as little or no carbs after 6pm and then try really hard to not eat anything for 12 hrs and then exercise first thing in the morning between 6am - 8am and then try and have a decent breakfast within 60 mins of my exercise program and this I do Mon-Fri. On Sat-Sun I may not exercise first thing but I do try and stay fasted for longer and say have breakfast as late as 9am or 10am.

I have been doing this for 2 months now and I must say, that as long as I go to the bathroom before I leave home and I am well hydrated, I have no noticed zero difference in my performance but a steady reduction in my body fat and overall weight (which is my aim).

I find that I am doing a 5km row which is spilt up in terms of a light warm up (as I cycle to the gym so I am warmed up already) and then do a series of fast 500m rows which are punctuated by a circuit of weights and machines (this keeps the HR high and stops me getting bored) and my 60min workout does not leaving me feeling like (I need food now) and I can cycle back home, at a pace, and not feel weak.

hjs wrote: Chris Froome does not eat before his training, he starts eating during his ride

A person who consumes over 5000 cal a day. Just when is all this fasting occurring. And, BTW, eating while riding is not easy to do. Minimal calories is all that can be gotten down as well as water. At the end of long stages, such riders are all in great deprivation, spending the rest of the day and night consuming, not fasting.

Cyclingman1 wrote:

hjs wrote: Chris Froome does not eat before his training, he starts eating during his ride

A person who consumes over 5000 cal a day. Just when is all this fasting occurring. And, BTW, eating while riding is not easy to do. Minimal calories is all that can be gotten down as well as water. At the end of long stages, such riders are all in great deprivation, spending the rest of the day and night consuming, not fasting.

Blablabla, as always factfree, fasting has nothing to do with limithing energy consumption, its about limiting the time window of eating.
From does NOT eat breakfast, so he FASTS, a good 10 hour before he starts his training. Ofcourse he eats enough, but weight is very important, tries to stay light as possible.
He does eat a good bit during his rides, and also sometimes takes a break to eat during.

Something tells me Cyclingman is ready to take a run at some more records.

There seems to be a good bit of confusion about when one eats and muscle glycogen stores. Not eating during the night and early morning does not deplete muscle glycogen. You may think you are burning mostly fats, but not so. Depletion of glycogen occurs after a couple of hard hours of exercise or several days. Do that, restrict carbs, and then see what you think about rowing 60 mins on a no carb diet, fasting, etc. The fact is that one cannot go fast without carbs. Fat burning is for slow going. Why do world class marathoners tend to hit the wall near the end. It's because their glycogen stores are nearly exhausted and their bodies cannot support 5 min miles on fat stores. They have to slow way down or hit the pavement. The same applies to cycling although the stomach is more accepting of food while on a bike, which also applies to rowing. One can stave off depletion to some extent on a bike.

G-dub wrote:Something tells me Cyclingman is ready to take a run at some more records.

Glenn, actually I'm not mentally or physically ready for more records. It's easy to lose the edge. I need cool weather.

It really shouldn't surprise me at this point since I've been a member of these forums for years, but the amount of BS that gets posted by people is just absurd.

Elite marathoners do not "hit the wall" because they run out of glycogen stores. Elite marathoners complete the marathon faster than the time it would take them to deplete their stores. The people who have to worry about "hitting the wall" are those who take over ~2:30 hours, which is about the time it takes for the average person to run out of glycogen. Now, most marathoners are not your "average" person, so most of them will actually have greater glycogen stores, especially if they know how to properly carb load. Even so, once you get above 3:00 hours or so you need to supplement yourself during the run otherwise your performance will be greatly affected.

There is a valid reason to train in a fasted state, but it only applies to certain workouts. Anything above SS intensity should not be done fasted as you need glucose to fuel your body at those intensities. Fasted training is usually done at SS intensity to promote more effective utilization of fat as a fuel. If you supplement with food or gels during that fasted workout, however, you're no longer fasting. The second you take in glucose (or fructose/sucrose) you're effectively shunting fat utilization for fuel.

Whether or not fasted training actually makes a significant difference in performance is another thing. I honestly don't think it matters either way - if you're comfortable training fasted, then do it; if you're not comfortable, then don't do it. It's not anything revolutionary nor will it magically make you a world-class athlete.

Cyclingman1 wrote:There seems to be a good bit of confusion about when one eats and muscle glycogen stores. Not eating during the night and early morning does not deplete muscle glycogen. You may think you are burning mostly fats, but not so. Depletion of glycogen occurs after a couple of hard hours of exercise or several days. Do that, restrict carbs, and then see what you think about rowing 60 mins on a no carb diet, fasting, etc. The fact is that one cannot go fast without carbs. Fat burning is for slow going. Why do world class marathoners tend to hit the wall near the end. It's because their glycogen stores are nearly exhausted and their bodies cannot support 5 min miles on fat stores. They have to slow way down or hit the pavement. The same applies to cycling although the stomach is more accepting of food while on a bike, which also applies to rowing. One can stave off depletion to some extent on a bike.

Please note I never said fasting overnight would deplete all muscle glycogen - I said it's the most depleted you're likely to get - without extended fasting. For normal people with normal lives etc, training in the am before eating is going to be as close to running on empty as they're gonna get.