Intermittent Fasting Test Results

Triathlon Forum
1

I like self experimentation and decided to give the 16:8 fast a go.

Stats
Male
6 foot
40 years old
135 pounds

Eats healthy - no sugar or simple carbs… lean meats, lots of veggies, salads and raw foods… avocados and healthy oils.

I normally eat 6 meals a day, starting when I wake up.

The Fast:

Alternating 16:8 and 18:6 for the past 7 days.

Fasted Swims
3000yds
2500yds
Swim time was about 4 seconds slower per 100 yards than non-fasted swims in the past. Super exhausted after these swims, as well. Both were 15 hours into the fast

Fasted Rides
25 miles
42 miles
Not bad. Kept the same avg mph and felt great. The 42 miler took ~2 hours 20 minutes and I took no fuel before or during, and no food till 2 hours after. The rides felt great.

Fasted Runs
Half marathon
7 miles
7 miles intervals
No issues here. Managed just over threshold pace for the 13.1 at 7:35/mile pace. The intervals also were not too bad. Managed 6:05/mile pace over the 10 200m intervals.

Eating
I didnt eat till 11am or 1pm everyday. Ate 2 meals per day with a bridge snack in the middle. Ate the same healthy foods but didnt count calories.
Surprisingly, I wasnt all that hungry. I usually eat a smoothie at 7am and an oatmeal at 10am. I am also hungry all morning and can barely make it to the oatmeal, then super starving after eating it.

During the fast, even though I skipped those two meals, I was less hungry. That was REALLY interesting. I LOVE this. I thought I was hungry cause I needed to eat, but I think it might have been habit.

Recovery
Feel great during workouts, but after I dont feel so good. Legs feel like the weigh 20 pounds all day and achy. This I will have to monitor.

Weight
Starting weight 134.8
Ending weight 136.8 pounds

Seriously, WTF? This does not make me happy. Everyone talks about how they lose weight. I gained weight? I didnt count calories, but kept an eye on what I was eating and know I was eating at maintenance and slightly below all week. I do this cause I am neurotic about my weight.

I am very upset at the weight gain, but it isnt a bad way to eat. I feel that the fasted workouts will be a real benefit moving into competitions, as well.

2

Holding for future updates.

Week 2 Results and Notes

http://forum.slowtwitch.com/forum/?post=6493127#p6493127

3

Shift your eating window to earlier in the day and follow Bill Lagakos on twitter and read his work on circadian rhythm.

4

I noticed the following:

Last summer I came back from a little injurie and had 2-3 punds to lose. I always eat healthy, like you but with lesss fat and more carbs (but healthy carbs).

So I had holidays, went on daily hardcore hikes and did something like 16:8. I got up in the morning and hiked for 4+ hours on an empty stomach. Usually it was 2200+ meters in elevation and 20+ km in distance.

I ate when I came home and again in the evening. In the afternoon I recovered on the couch watching the Tour. I didn’t count calories, but I certainly wasn’t overeating and if anything I think I ate LEDs than I should have. But those 2-3 punds wouldn’t go away.

Than I got on a small vacation. I would eat breakfast, go on a run, eat lunch, enjoy the time and then eat dinner always with a dessert. I trained daily but had less overall activity and I think I ate more.

When I got home after the vacation, the 2-3 pounds were away.

I think because I underfueld, my body was unwilling to let go of anything and shut down. And I think that can also be dangerous for injuries.

I guess fasting is a fine thing, but one should not overdo it. Escpecially when training hard. You can do 16:8 but probably not everyday.

5

Interesting… Thanks for your reply. Injury is my primary fear with this test.

I did think it was something you do every day, so I was gonna keep a running journal since it is such a big difference in the way I used to eat. I feel I make a great case study as I was completely opposite of fasting and have perfect self control to experiment.

6

Weight
Starting weight 134.8
Ending weight 136.8 pounds

Seriously, WTF? //

Really?? You are 6 ft and 135lbs and you are trying to lose weight? Mad because you gained 2lbs? Either this is the sneakest back door brag or you have some body issues. You should be about 150/155, unless you are a sub 2;10 marathon runner…

7

Weight
Starting weight 134.8
Ending weight 136.8 pounds

Seriously, WTF? //

Really?? You are 6 ft and 135lbs and you are trying to lose weight? Mad because you gained 2lbs? Either this is the sneakest back door brag or you have some body issues. You should be about 150/155, unless you are a sub 2;10 marathon runner…

What monty said.

8

I used to weigh 225 pounds of pure fat. So, I am paranoid about weight.

Not trying to lose weight but don’t want to gain.

9

Seriously. Not wanting to get too deep into weight, but I wonder if you added muscle or something. At your height/ weight I wonder if performance would be a better metric than pounds. Or body fat % at least.

10

Congrats on losing so much weight and keeping it off. Regardless of the rationale for your weight, this isn’t healthy.

11

Seriously. Not wanting to get too deep into weight, but I wonder if you added muscle or something. At your height/ weight I wonder if performance would be a better metric than pounds. Or body fat % at least.

^This.

Scale weight is just a number that doesn’t necessarily mean anything. I know many skinny people who have a high percentage of body fat and are extremely weak. Conversely, some who would be “overweight” by standard charts, are lean ripped performance machines. They usually don’t care too much what their weight is, but do care about the muscle to fat % ratio and how they feel overall. Since you have a healthy diet already, focus on fueling your body properly for performance and take the focus off a number on a scale.

12

Ha. I’m the weak, no muscle version. But I don’t think I have a high BF%.

13

You are very unhealthy at that weight and need to take some serious medical advice - I don’t to piss on someone who needs help so will leave it at that
.

14

Ha. I’m the weak, no muscle version. But I don’t think I have a high BF%.

So your experiment shows:
Healthy eating through the day, combined with a fair chunk of exercise = you feel good, and weight is really low.Fasting through a lot of the day, combined with a fair chunk of exercise = you don’t feel good, and your weight goes up.
Now I’m not a dietician. Just a 5 foot 9 1/2 inch, 143 pound guy (age over 50). But it sounds to me like your body is on the verge of being in starvation mode, where fasting is kicking your metabolism into a ‘preserve calories at all costs’ state. Focus on healthy eating through the day, keep up your exercise, and let the weight be what it will be, at least up into the 150 pound range. You might find that you will put on some muscle, which is good all around since it helps with injury prevention as well as burning more calories through the day.

Go see a diet specialist and maybe someone that can help you kick the “I’m worried about getting fat at 135” thinking.

15

What I don’t understand is why you would think about fasting, intermittent or any kind of weight loss at your current weight. Surely you were not looking to lose more
I agree with other posters that 6 ft and 135 is dangerously low and you say you are weak? Why not try to put some muscle on instead of fasting?

16

Seriously, WTF? This does not make me happy. Everyone talks about how they lose weight. I gained weight? I didnt count calories, but kept an eye on what I was eating and know I was eating at maintenance and slightly below all week. I do this cause I am neurotic about my weight.

I am very upset at the weight gain, but it isnt a bad way to eat. .

You are 6 ft tall and ~135lbs? You should be working on gaining weight, not losing weight. I don’t know you from Adam, but I’m concerned with your attitude toward your weight when you are already too light.

17

“You are very unhealthy at that weight and need to take some serious medical advice - I don’t to piss on someone who needs help so will leave it at that”

Every single post here says the same thing; you are probably what I would term “skinny fat” at that weight. The next healthy step for you would be to get a scale that offers body fat/muscle ratio in addition to just the scale.

As nearly everybody else also said, you should be fixating on muscle GAIN and not weight loss.

18

Wow. This turned into a thread about me being underweight.

I used to be 225lbs. I couldn’t walk a tenth of a mile. Took time to lose the weight slowly and methodically over a few years by running and P90x.

I now run sub 20 5Ks, half marathons under 1:40 and so on.

I have been at my current weight for the past three years. The three years prior to that I was in the 155-160lb range, but still had a beer belly.

I agree with everyone that I need muscle. I also agree that I have mental issues with weight. That comes from remembering how hard it was to lose.

With the fasting, I thought it was supposed to help build muscle by increasing the production of growth hormones (I researched for weeks). That is one reason I was doing it.

19

Hey Spartan, thanks for the clarification attempt. Sorry if we were being too judgmental. I guess goes with the territory.
That is great that you lost so much weight. I think people were just concerned. And you take all these arm-chair-quarterback comments pretty well I must say. I’m sure you know there is a happy medium with all.
I would definitely take the posters advise who said to check out a dietician. They can probably assist you. Best of luck.

20

you need to still hit your macro nutrients in the 8 hour window for it to work. You also need to be lifting weights for this to really help build muscle. if you are eating less during the 8 hour window you need to make sure you eat your calorie and macro-nutrient numbers during that time. It sounds like this might just not be for you. I would say if you can fund it speak to a registered dietitian to get these macro nutrients figured out for you.