fasted exercise

*zap*

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I have no idea what aclit is.

What I am saying is that to raise your aerobic capacity the best way is to do long duration and frequent low intensity aerobic exercise. That will lift your base. High intensity workouts need to get worked in also....but the majority would be low intensity. What is low intensity will vary from person to person as far as heart rate. Especially when you are doing this for years....ymmv.
 

Anglo-American

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I did this regular when training/ running mountain marathons.
You can in time go extremely hard in a fasted state. Perhaps harder then if non fasted in my experience.
I'd run 20 miles before breakfast and work, basically every weekday morning. Then mountain races at the weekend, (Saturday hopefully) then rest day Sunday.
...then I had kids, so that ultimately put a stop to it.

Zap is correct. 80 - 90% of training should be very easy. As in you should be able to comfortably hold a conversation whilst exercising. The remaining 10-20% should be so intense that your heart feels like it's going to beat out of your chest.

This will get you very fit, very quickly and reduce risk of injury.
When training cardio the quickest part of the body to respond is your respiratory system, (heart and lungs) Then muscles. Tendons and ligaments. Bones.
Training in the middle zone, and not being mindful of building up your bodies durability alongside fitness are the causes of meny injuries. As is bad form.
Most men train in the middle zone.
 
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pattimusprime22

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Soooooo.... it's been hotter than hell here going on three weeks, which has forced me into hitting the trails early (thankfully we're cooling down by morning!); early enough, it's easier to get my hour to two hour hikes in before eating breakfast.

I've read about fasted exercise a fair bit on the Uphill Athlete site. Their take is that fasted exercise helps the body better activate fat calories on longer events (ie endurance ie hunting :D). Evidently after 12 hours (6 at the very least) your glycogen stores are depleted, so recruiting needed calories (if you haven't eaten) comes from fat.

They also stress that this fasted exercise should be on the lower key end- not sprinting, not HIIT, hiking/running/biking at a lower heart rate- their "zone 2". I don't use a heart monitor, but from my reading I think I'm pretty solidly in zone 2 most of my hiking (probably zone 3 on some of my longer climbs).

Not a weight loss strategy as near as I can tell, just a strategy making a person more efficient moving through the hills/mountains by utilizing body fat in addition to calories consumed while out. They do stress that for an actual "event" you want to hit the calories pretty hard (leaning more on carbs as they metabolize quicker)

I don't notice any less energy w/o breakfast or anything else much out of whack; but breakfast sure tastes good though!

Anyways I've read about it several times, never really considered it, but now by happen chance- I'm doing it :)

I don't think there is anyway (save some expensive, complicated scientific testing) to quantify results, but thus far it sure hasn't hurt anything.
I really enjoyed their book Training for the Uphill Athlete. I would guess with your aerobic base that you could just use nasal breathing/talk test as a good enough proxy for zone 2 (what they define as AeT). As far as validating that fasted training is helping with fat adaptation, you're probably right that you'd need to go get some metabolic testing done in a lab. I'm good with just trusting in their expertise and doing fasted zone 1 or 2 training when convenient.
 

Cactus kid

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Ill just reiterate what zap and others who follow TFTNA methodolgy (which I have for the past couple years)

Steve Johnson states you push up your aerobic base from the bottom, not pull it up from the top. Meaning the only way to see improvements in your low end aerobic capacity is to spend a good amount of training in that zone. Training at a higher heart rate does not build the aerobic base.

As stated, training int he "middle zones" will lead to stagnation. Train really high a little, train really low a lot.

I do all of my zone 2 training fasted, including 4 hour plus hikes. This in training only. I am a "butter burner" naturally.
 

Marbles

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I agree with @Zap

Part of the reason for training at the bottom is that slow twitch muscle fibers consume lactate for energy while fast twitch fibers produce lactate during anaerobic activity. Improve the slow twitch fibers function and you increase lactate clearance, which rases lactate threshold. Even world class sprinters spend a large amount of time training at low intensity.

From my own experience, dropping intensity really helps avoid over training and injury.
 

Mike Islander

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I have no idea what aclit is.

What I am saying is that to raise your aerobic capacity the best way is to do long duration and frequent low intensity aerobic exercise. That will lift your base.

That's what she said. :)

ACLIT = what you said; "aerobic capacity low intensity training" (A. K. A. LISS).
 
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sahunter06

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Agree with @Marbles and @Zap
My early morning rucks are in a fasted state. Keeping my hr 150-160 target then hill climbing getting it around 200. By 6:00am I’ve already fasted 11 hours. Have a few cups of black coffee. I will wait another 3-4 hours after my ruck to eat.
I’ll fast for 16-18 hours depending on what I had for dinner and have been doing so for over a year now. My body is used to it, but when I workout in the morning or tuck I do t have a drop in energy like I used to. My strength is increasing as well. Not to mention I’m leaning up but not intentionally. Just a result of my process.
 
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mtwarden

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I tried a little experiment the other day. I picked a pretty steep loop, knowing that I'd be out of zone 2 and into zone 3 (tiptoe steep in places). It was only 4 miles, but gains 1400' in two miles.

Happy to report no ill effects being fasted. My guess is if the following two miles weren't downhill and continued climbing- I probably would start bumping into the wall????
 

Marbles

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Does fasting include water?
Most of the time fasting is defined 1 of these 3 ways.
1. No calorie intake (0 calorie favored thing are ok like vitamin water, artificial sweeteners, gum)
2. No intake that triggers insulin release (limited to pretty much water, black coffee, and real tea)
3. Not enough calorie intake to provide energy (something like less that 500 calories in 24 hours)

2 is the easiest to do in my opinion and probably the most beneficial.

Dehydration can happen fast, even if not exercising, fasting from water is potentially dangerous.
 

bdan68

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If you have enough body fat, dry fasting is not dangerous. It's a great way to speed up weight loss. There's a lot of water in body fat and if you're not taking in water your body will burn the body fat for the water it needs.
 

Marbles

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If you have enough body fat, dry fasting is not dangerous. It's a great way to speed up weight loss. There's a lot of water in body fat and if you're not taking in water your body will burn the body fat for the water it needs.
Fat is hydrophobic, so there is no water in it. However, the end products of complete combustion (whether it is fat/glucose/protein metabolism, or burning wood in your fire place) is CO2 and H2O.

Dehydration appears to slow metabolism and lead to long term weight gain in multiple studies.

The Army found that 5% reduction in body water results in experience navigators being unable to perform basic navigational tasks.

Athletes dehydrate themselves to make weight in a sport, nothing about the practice is healthy and as it tends to take days to replenish cellular water most of them are paying a price in performance to be in a lower weight class as they cannot adequately rehydrate between weigh in and competition.

Burning 22 pounds of fat produces 18.5 pounds of CO2 and 3.5 pounds (1.6 liters) of water. 22 pounds of fat is 77,000 calories. Just from sitting in a chair you loose about 0.8 liters a day, that does not include urination, which should account for another 0.8 to 2 liters of output. So, it would take 15 days of burning 5000 calories a day to produce enough water to account for what you loose in 24 hours.
 
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