Post-Trip Struggle

It's been over three weeks since I returned from the week-long trip to Socal and I am still struggling and yet to return to the pre-trip condition. Here is the graph of the 7 day rolling sum of steps taken before, during and after the trip:

The number of steps after the trip is substantially below the numbers before the trip. To make it worse, I've been more susceptible to post-exertional sickness: I got sick twice since I returned from the trip. They were both triggered by activities tolerated before the trip:

This is similar to the condition I was in prior to the improvement in June. So, basically I gave up most of the improvement which has been fading and then reappearing periodically since. This certainly makes me rethink about the upcoming cross-country trip that I've been planning. If I don't give it up, I will certainly will have to moderate it more than I was planning.

On the next post,  I'll compare this post-trip struggle with the previous ones and talk about the theories for the post-trip struggle.

Thanksgiving Week Trip

Thanksgiving was a good excuse for a test run for the upcoming cross-country trip that I've been planning. We rented a Ford Fusion Hybrid from Getaround for a week and went down to socal. It was a 1000+ mile trip spanning LA and San Diego on I5 and then US101/CA1. Yeah, I paid price for this trip and struggled when I came back. More on it later.

Day 1 - Drive all day to San Diego (7000 Steps)
It was not a good start. The trip planning was rather stressful and I fatigued out despite the preemptive rest of 2 days. I had to frequently  pull over, crawl to the backseat and lie down with my legs sticking out the window for 15 minutes at a time. How I wished the car would drive itself. You know how just  holding the steering wheel can be a struggle if you are a CFS patient. When we got to Fresno, I emailed Tesla to add the autopilot option on my order of Tesla S. An $8000 option, but it will be well worth, especially for CFS patients, if it does what it promises to do.

To make things worse, I did not account for the traffic in LA. By the time we got there it was a rush hour and the freeways were all clogged up. After 30 minutes of futile attempt, I gave up and headed to my sister's house in LA instead. We had dinner, stayed there till 8PM and then restarted to San Diego. It was past 10 PM when we got to the hotel in San Diego. Strangely, I was in a better shape than when we left San Francisco. We walked a few blocks around the Gaslamp Quarter and then went to bed.

Day 2 - San Diego (9000 Steps)
Coronado, Midway, Little Italy, Cabrillo, Mission Bay. It was a whirlwind the next day. I wasn't sick despite the ordeal the previous day. That's probably because I did not walk much; sitting up or driving is not as fatal as walking. I was pretty tired by the time we got to Cabrillo vista point though. I lied down on a bench for 15 minutes. But I felt better as the day wore on. The traffic was a mess however. It took us over 5 hours to travel 130 miles. The plan was to get to my sister's for dinner, but the traffic was so bad we had to pull over about 30 miles from LA and had a fast food dinner instead.  At the end, I not only survived 3+ hours of nonstop driving, but I still had energy left. It could've been the effect of Sudafed that I swallowed in the morning. On top of the excitement effect.

Wife commented how different people in San Diego was from San Franciscans. She thought they were more portly and less fashionable. In other words, more American. It is a military town and has number of sailors and retirees.

Day 3 - Rest in LA (7000 Steps)
I pooped out the next day. Not sick, just wiped out, despite logging 9000 steps the previous day. It wasn't a sustained walk though, so its effect must've been moderated. It was a low intensity activities spread out throughout the day, much like running errands on public transportation. My sister and her husband drove us to Griffith Observatory in the afternoon and that is all we did during the day. Then family get-together and dinner with another sister's family.

Day 4 - Hollywood and Beverly Hills (10000 Steps)
This standard affair for first-time visitors of LA was for my wife. I was in a decent shape after a day of rest.

Day 5 - LA downtown and Santa Monica (12000 Steps)
Day 4 was for me. I haven't explored LA historic sites and wanted to check out the new Expo line to Santa Monica. I've turned into a public transportation freak since I got rid of my car 6 years ago.

The Expo line was a flop. There was nothing to see; it was 50 minutes of boring scenery. Coming from SF, Santa Monica wasn't anything to write home about either. It's a cross  between Santa Cruz and Ocean Beach, only with a lot more people. We should've spent the time on LA Dart buses exploring LA downtown more.

If you are visiting LA, go to the information center in Paseo De La Plaza, pick up the Dart bus map. You can explore a lot more that way and also avoid getting ticketed for parking in LA downtown.

Day 6 - Drive to Carmel (8000 Steps)

We left for Carmel around 9AM. We drove on US 101 this time, stopping at various vista points for views and picture taking. Then we had to stop in San Luis Obispo for lunch and bathroom. We got to Hearst Castle after 2PM. There were too many people and we didn't feel like spending $50 to see the gaudy place. So we headed straight to Carmel after another bathroom break.

It must be the elephant seal mating season. There were about a million of them lounging on the cold and rainy beach or fighting each other in the water. None seems to have CFS. I suppose the sick ones died off. I sometimes imagine what would've happened if I weren't financially  independent. I probably would have moved in with one of my siblings, or died on the streets.

We got to Carmel after dark. I negotiated $50 off at the Comfort Inn and then crashed on bed for a while before going out for a dinner at La Bicicletta.

Day 7 - Point Lobos, Carmel, Monterey, Santa Clara, Home (8000 Steps)

After the breakfast at the inn, we took a stroll at the Carmel Beach. Wife did some shopping and we came back to the inn and rested for a while. Then we checked out and went back south to Point Lobos.

This was where I used to come for hiking. The last time was actually while I was sick with a bout of Over Training Syndrome in 2008 -- I had a visitor and had to take them on a sightseeing tour. I got sick in April that year. Then I recovered for a few weeks and before permanently relapsing in July.

After Point Lobo was Monterey and Pacific Grove. The last time there was in September 2007. I organized a bike ride for Stanford Outing Club from Monterey to Point Lobos through the 17 Mile Drive and then back. It must've been about 30 miles of ride. I remember a long stretch of uphill around Carmel. I struggled on it on my old rickety bike, I even wrote a poem about it.

Anyway, it was a trip down the memory lane. And it made me double my resolve  to hike and bike one more time before I go home  (in the sky) for good. (Yeah I know, setting a goal is about the worst thing you can do if you are a CFS patient)

Post-Trip
All in all, it was the longest trip I've taken since I got sick with CFS. Probably the most active trip too, with almost 60k steps over a week. On the next post, I'll report the post-trip struggle and comparison with previous trips to draw some some conclusions about my progress with CFS.

CFS While Sleeping

Have you woken up in the middle of the night and felt healthy? I have, many times. Sometimes I sleep deep for 4 or 5 hours and wake up, and feel no pain or weakness in my legs at all. It's as if I recovered.  This usually happens after a day of long walk. Then I go back to sleep and, when I wake up in the morning, I'm back to achy, weak and fatigued self all over again.

Using your muscle does tremendous damage to your body. And your body produce literally thousands of biochemicals to repair the damage. And then there is immune system response that lasts several days. Healthy people don't know it because the body automatically repairs in the background.

Sleep is probably part of that repair process. Your body may be producing different biochemicals as your sleep progress. And it's possible that, in early stage, it is suppressing whatever is irritating CFS patients, and then restore the normal state by the time you wake up. It would be interesting to draw blood every hour and see how the biochemistry changes while you sleep, like the study that tested blood every hour for 3 days after exercise.

Pace as the Fatigue Measurement

As I promised, I measured my pace and correlated it with my subjective fatigue rating over 4 week period. The data looks as follows:

date	duration	fatigue
9/17 9:02	19.71	5
9/17 9:45	20.25	4.8
9/17 11:30	19.01	5.1
9/17 11:30	18:53	5.1
9/17 12:02	18.69	4.9
9/17 12:02	19.37	4.9
9/17 18:08	17.56	5.2
9/18 10:46	18.69	5.1
9/18 12:07	18.9	5
9/18 14:45	19.61	5
9/18 10:48	16.75	5.3
8/18 14:02	18.09	5
8/18 20:13	17.61	5.2
8/19 11:40	17.94	5.2
8/19 15:35	18.78	5
8/21 11:51	17.61	5.1
8/21 12:44	18.64	5
8/21 14:12	18.35	5
8/22 9:50	17.9	5.2
8/23 9:33	17.39	5.2
8/23 9:58	17.2	5.3
8/23 13:04	18.55	5
8/23 11:58	17.81	5.1
8/25 8:46	18.56	5
9/25 10:58	17.45	5.2
9/25 23:02	17.2	5.3
8/27 16:44	18.12	4.9
9/28 16:57	17.42	5.3
9/29 10:38	17.96	5.1
9/30 12:59	19.28	4.8
10/2 10:34	16.78	5.3
10/3 13:51	17.83	5
10/4 10:48	17.21	5.2
10/4 13:09	18.41	5
10/4 18:02	18.28	5
10/4 20:08	16.45	5.3
10/5 9:37	16.49	5.3
10/6 11:24	16.82	5.2
10/7 11:25	17.77	5
10/7 20:43	15.87	5.3
10/8 11:43	16.69	5.3
10/8 20:20	18.08	5
10/8 11:23	16.96	5.2
10/8 12:20	17.45	5.1

The duration is the amount time in seconds that took for walking 29 steps. (I meant to do 30 steps, but I started counting from 1 instead of 0, so I ended up with 29 steps). The fatigue is my subjective fatigue rating as usual. The resulting scatter plot between the duration and fatigue looks like this:

The walking speed is nicely correlated to the fatigue as you can see. (The Y scale looks funny, that's what R does when you do as.numeric(pace$duration), but it is properly scaled). The correlation comes out to be 84%.

The problem with this study, of course, is that I am both the investigator and the subject: there is no blinding whatsoever. As result, it is highly susceptible to bias. But the result is at least encouraging. Next, I will write an android app to automatically measure my pace without my knowing it so that I'll be blinded to it, and see if that correlates to the fatigue level as well.

If you want to try this yourself, do the following to minimize the bias:

1. Declare your fatigue first.
2. Walk fixed number of paces and measure the time.
3. Focus on how your leg feels. Make sure that you are walking as fast as possible without any straining at all.
4. Whatever you do, do NOT revise your fatigue rating after the walk. It is tempting, as you realize while walking that your fatigue is not what you thought it was. But the error is random and therefore will cancel out on average.

Dopamine Supplement Doesn't Work

I mentioned about being able to walk further when in a new environment or routine. I figured it could be a dopamine effect, so I tried a dopamine supplement to see if I could get the effect without changing my environment. Well, it didn't work. I tried it for a month and there hasn't been any improvement. Here is the graph:

August 21 is the date I started taking 2 dopa pills. As you can see, the 7 day rolling sum of the number of steps taken actually decreased.  Part of it got to do with getting sick after experimenting with squats, etc. But you'd expect the CFS threshold is raised with dopamine and therefore I should get sicker less often. Apparently it didn't. This, of course, is only a month worth of data with one patient, so I can't draw any conclusion. But it certainly doesn't give me any reason to experiment further with it.

The dopamine supplement, by the way, was DOPA Mucuna from Amazon.

This doesn't necessarily invalidate the dopamine theory. It only means that the dopaminergic supplement didn't work for me. Motivation and excitement may still work. My next plan? Stay tuned.

Out of Jail After 3 Days

It's good to be "healthy" again. I just got of the jail of post-exertional sickness of 3 days after adding 2 squats to my daily routine. In the nick of time too; my refrig was totally empty. I went out for errands on Muni and restocked it.

When you are constantly sick, you don't really know how sick you are; post-exertional sickness is just worsening of your symptoms. When you improve enough though, you realize the post-exertional sickness is really flu-like: it has clearer onset and recovery. And you know how fresh and free it feels when you recover from a flu after being sick for a few days.

Measuring Fatigue with HRV Doesn't Seem to Work

In the paper "Frontier Study of Fatigue.." the Japanese researchers claim that measuring HRV is a reliable way to measure fatigue. They compared HF/LF measure to patients' subjective fatigue as determined by Chalder Scale and SF-36 survey. Also, over at healthrising.com, one of the members posted her experience with HRV and showed the correlation to her post-exertional sickness.

Since I got Polar H7, I decided to give it a try. I downloaded Elite HRV, a free android app, and measured morning readiness when I wake up. I also measured HRV at various times throughout the day. Below is the data over a period of one month:

                  Date hrv balance fatigue morning afternoon evening
1   8/10/2016 11:57:00  49      NA      NA      NA        NA      NA
2   8/10/2016 14:37:00  45      NA      NA      NA        NA      NA
3   8/10/2016 20:06:00  51      NA      NA      NA        NA      NA
4    8/11/2016 8:44:00  48       6      NA     4.9       5.1     5.0
5    8/11/2016 8:44:00  49      NA      NA      NA        NA      NA
6   8/11/2016 12:00:00  42      NA      NA      NA        NA      NA
7   8/11/2016 16:27:00  58      NA      NA      NA        NA      NA
8   8/11/2016 20:09:00  47      NA      NA      NA        NA      NA
9    8/12/2016 8:15:00  63       7      NA     5.1       5.0     5.2
10   8/12/2016 9:32:00  55      NA      NA      NA        NA      NA
11   8/12/2016 9:36:00  51      NA      NA      NA        NA      NA
12  8/12/2016 12:00:00  56      NA      NA      NA        NA      NA
13  8/12/2016 15:04:00  51      NA      NA      NA        NA      NA
14  8/12/2016 19:54:00  47      NA      NA      NA        NA      NA
15  8/12/2016 20:30:00  47      NA      NA      NA        NA      NA
16  8/12/2016 20:57:00  48      NA      NA      NA        NA      NA
17  8/12/2016 21:51:00  53      NA     5.2      NA        NA      NA
18  8/12/2016 21:53:00  52      NA     5.2      NA        NA      NA
19  8/12/2016 21:55:00  54      NA     5.1      NA        NA      NA
20  8/12/2016 22:14:00  54      NA     5.1      NA        NA      NA
21  8/12/2016 22:44:00  47      NA     5.1      NA        NA      NA
22   8/13/2016 8:43:00  51       9     5.1     5.2       5.0     5.4
23  8/13/2016 11:01:00  46      NA     5.2      NA        NA      NA
24  8/13/2016 11:32:00  53      NA     5.2      NA        NA      NA
25  8/13/2016 12:51:00  45      NA     5.1      NA        NA      NA
26  8/13/2016 13:20:00  44      NA     5.0      NA        NA      NA
27  8/13/2016 16:39:00  56      NA     5.0      NA        NA      NA
28  8/13/2016 17:19:00  53      NA     5.0      NA        NA      NA
29  8/13/2016 18:52:00  47      NA     5.2      NA        NA      NA
30  8/13/2016 20:33:00  43      NA     5.3      NA        NA      NA
31   8/14/2016 7:23:00  44       6     5.2     5.2       5.0     5.0
32  8/14/2016 10:19:00  52      NA     5.0      NA        NA      NA
33  8/14/2016 20:38:00  50      NA     5.0      NA        NA      NA
34  8/14/2016 22:53:00  46      NA     5.2      NA        NA      NA
35   8/15/2016 7:25:00  50       9     5.0     5.0       5.2     5.3
36  8/15/2016 14:38:00  39      NA     5.0      NA        NA      NA
37  8/15/2016 15:13:00  48      NA     5.2      NA        NA      NA
38   8/16/2016 9:03:00  48       8     5.3     5.3       5.2     5.2
39  8/16/2016 18:37:00  45      NA     5.2      NA        NA      NA
40   8/17/2016 9:38:00  48       8     5.1     5.0       5.0     5.0
41  8/17/2016 17:34:00  47      NA     5.0      NA        NA      NA
42   8/18/2016 8:33:00  58       7     5.1     5.2       5.2     5.1
43   8/18/2016 8:38:00  54      NA     5.1      NA        NA      NA
44  8/18/2016 10:33:00  48      NA     5.2      NA        NA      NA
45  8/18/2016 13:09:00  46      NA     5.0      NA        NA      NA
46  8/18/2016 17:14:00  51      NA     5.1      NA        NA      NA
47  8/18/2016 17:17:00  49      NA     5.1      NA        NA      NA
48  8/18/2016 12:09:00  53      NA     5.2      NA        NA      NA
49   8/19/2016 9:03:00  48       8     5.4     5.3       5.0     5.0
50   8/19/2016 9:08:00  44      NA     5.3      NA        NA      NA
51  8/19/2016 11:45:00  50      NA     5.0      NA        NA      NA
52  8/19/2016 14:02:00  41      NA     5.1      NA        NA      NA
53   8/20/2016 8:48:00  51       9     4.9     5.1       5.1     5.1
54   8/20/2016 8:52:00  55      NA     4.9      NA        NA      NA
55  8/20/2016 15:13:00  41      NA     5.1      NA        NA      NA
56  8/20/2016 17:05:00  56      NA     5.2      NA        NA      NA
57  8/20/2016 21:14:00  50      NA     5.0      NA        NA      NA
58   8/21/2016 9:39:00  49       8     5.2     5.3       4.9     5.1
59   8/21/2016 9:42:00  43      NA     5.3      NA        NA      NA
60  8/21/2016 14:17:00  46      NA     5.0      NA        NA      NA
61  8/21/2016 16:55:00  47      NA     4.9      NA        NA      NA
62  8/21/2016 18:08:00  47      NA     5.1      NA        NA      NA
63  8/21/2016 21:13:00  47      NA     5.2      NA        NA      NA
64   8/23/2016 7:51:00  46       7     5.2     5.3       5.1     5.3
65   8/24/2016 8:04:00  51      10     5.0     5.3       5.2     5.2
66   8/24/2016 8:10:00  51      NA     5.0      NA        NA      NA
67  8/24/2016 18:47:00  48      NA     5.1      NA        NA      NA
68   8/25/2016 7:42:00  48       8     5.2     5.3       5.2     5.0
69   8/26/2016 8:19:00  49       8     5.2     5.3       5.1     5.3
70   8/26/2016 8:22:00  47      NA     5.2      NA        NA      NA
71   8/26/2016 9:43:00  47      NA     5.2      NA        NA      NA
72  8/26/2016 12:25:00  51      NA     5.2      NA        NA      NA
73  8/26/2016 12:27:00  48      NA     5.2      NA        NA      NA
74  8/26/2016 12:29:00  47      NA     5.2      NA        NA      NA
75  8/26/2016 12:35:00  50      NA     5.2      NA        NA      NA
76  8/26/2016 12:52:00  47      NA     5.0      NA        NA      NA
77  8/26/2016 12:54:00  50      NA     5.0      NA        NA      NA
78  8/26/2016 16:05:00  32      NA     5.0      NA        NA      NA
79  8/26/2016 16:21:00  33      NA     5.1      NA        NA      NA
80  8/26/2016 16:36:00  31      NA     5.2      NA        NA      NA
81  8/26/2016 18:04:00  50      NA     5.1      NA        NA      NA
82   8/27/2016 8:24:00  45       6     5.1     5.3       5.4     5.1
83   8/27/2016 8:28:00  43      NA     5.1      NA        NA      NA
84   8/27/2016 8:29:00  38      NA     5.1      NA        NA      NA
85  8/27/2016 14:12:00  50      NA     5.0      NA        NA      NA
86   8/28/2016 9:57:00  41      NA     5.1      NA        NA      NA
87  8/28/2016 10:00:00  40       3     5.1     5.1       5.2     5.3
88   8/29/2016 9:14:00  50       8     5.1     5.1       5.0     5.3
89   8/29/2016 9:17:00  47      NA     5.1      NA        NA      NA
90   8/29/2016 9:19:00  46      NA     5.1      NA        NA      NA
91   8/30/2016 8:48:00  46      NA     5.1      NA        NA      NA
92   8/30/2016 8:49:00  46       8     5.1     5.0       4.9     5.1
93  8/31/2016 10:08:00  49       9     5.1     5.3       5.1     5.1
94  8/31/2016 10:11:00  47      NA     5.1      NA        NA      NA
95    9/1/2016 9:23:00  45      NA     5.1      NA        NA      NA
96    9/1/2016 9:25:00  43       6     5.1     5.1       4.9     4.8
97    9/2/2016 9:17:00  48      NA     5.2      NA        NA      NA
98    9/2/2016 9:19:00  42       6     5.2     4.9       5.0     5.0
99    9/3/2016 8:07:00  48      NA     4.9      NA        NA      NA
100   9/3/2016 8:11:00  44       8     4.9     5.3       5.1     5.0
101   9/4/2016 9:20:00  50      NA     5.1      NA        NA      NA
102   9/4/2016 9:24:00  42      NA     5.1      NA        NA      NA
103   9/4/2016 9:26:00  40       6     5.1     5.3       5.2     5.2

And here are the scatter plots between readiness/balance and fatigues throughout the day and the correlations:

And finally, the scatter plots between 1 minute snapshot hrv taken throughout the day and fatigue:

HRV is the high frequency variability measured by RMSDD of R-R distance of the heart beats. Balance is the balance between sympathetic and parasympathetic activities, and the higher the better it is. Elite HRV computes this values based on how far HRV is from the optimum value. Fatigue is my subjective fatigue rating.

As you can see from the scatter plots, there isn't much correlation between the ANS balance or HRV and fatigue. They range from -20% to +23%. (One could question my subjective fatigue rating, but I do have enough confidence in it since it correlates 81% to time spent lying down).

It's only a month worth of data, so I can't draw a definitive conclusions from it. But the HRV and balance are all over the map, I basically lost interest in pursuing it further. Maybe HF/LF measure, as done in the Frontier Study of Fatigue, will have a better correlation. But LF  measure is influenced by both sympathetic and parasympathetic nerve, and is therefore controversial. Even if it works, HRV method poses logistical problem as it requires the patients to lie down for over 5 minutes  and pace the breathing. It is not a viable measure of fatigue. Especially if it requires medical grade equipment as done in the Frontier Study.

For now, I'm moving on to the walking pace as the measure of fatigue. It has an advantage of not requiring any action on the patient's part and I think it'll correlate to overall fatigue better because fatigue will result in sluggishness and slower walking pace whether it is sympathetic, parasympathetic, mental or physical. Stay tuned.

Squats, Still a Killer Exercise

How is it possible that I can walk 2.5 miles (with 3 breaks) and yet two squats send me to the pound? I knew that squats can make me keel over. But I decided to experiment again since I have the improvement under the belt. No luck. I threw in two squats to the daily regimen and I got sick for 3 days.

Enough with the experiment. I now know that there is no discernable improvement in the walking speed or squat. I'll try again when I can walk 5 miles. (Yes, the walking speed increases arithmetically as the distance increases exponentially).

CFS as Hibernation

Spent 3 days in a bad mood. Apparently cleaning the bathroom the day after walking 2 mi and then walking 2 mi again the day after was too much. The cumulative effect of exertion is still alive and well; it is only less pronounced because my tolerance to exertion went up.  I'll have to go back to cleaning the bathroom in lieu of, not in addition to, the (bi-daily) walk.

Now, today's topic. The UCSD researchers announced this week that they discovered anomaly in the metabolomics of CFS patients. Out of 600 or so metabolites they tested, 80% were severely reduced compared to matched controls. From this, they speculated that CFS patients are in a hibernation state like Dauer worms. For some reason, the body is mistakenly putting the patients in a hypometabolic state that only allowed survival and no more, at a great expense to the quality of life.

One issue with this theory is that humans don't hibernate. Dauer worms and bears can slow down their metabolism, lower body temperature and burrow into a hole or cave. For humans, hibernation means death unless fed and taken care of by other humans. That not a viable evolutionary strategy generation after generation. So it can't possibly be an evolutionary adaptation. Perhaps it is an ancient cellular level response (they call it CDR, or cellular danger response) mistakenly activated. But that still does not explain slew of neurological CFS symptoms. Worse yet, you can't explain with the hibernation theory the ability to exert normally only to get sick the next day.  (If you are in a dauer state, you should not be able to exert at the first place). So, for now,  the metabolic anomaly is more likely than not yet another symptom of CFS rather than the cause of it.

The problem with CFS research that I see is that researchers focus on their specialties and then speculate whatever the anomaly they find as the cause of CFS. Thus, virus people blame EBV, psychiatrists blame depression, endocrinologists blame HPA axis, and geneticists blame genetic expressions. Now we can add to that growing list gut microbiome and metabolomics.  It's the proverbial blind men and the elephant. What we need is a creative thinking, as recently done in schizophrenia and alzheimer's, that can put together all these clues and zero in on the real cause, so that we can come up with a real solution. The problem is, with only $5 million dollars out of NIH's gazillion dollar budget allocated to CFS research, it's not going to attract a lot of researchers. Quantity usually leads to quality in research, and we need that quantity to solve this problem.

As far as I am concerned, CFS is still a neuromuscular disorder, mediated by the immune system.
I think the term Myalgic Encephalomyelitis will ultimately proven right, except that it is the inflammation sensitivity, not the inflammation itself. And the paper's finding that the metabolic response was the opposite to the response to infection or inflammation only proves that there is no infection or actual inflammation in CFS.

Improvement, Graphed

I talked about my recent sudden improvement. Here is the graph of weekly number of steps, taken with Fitbit and graphed with R. The second one is zoomed version from June to August.

It shows almost two fold increase in late June. Then, in early July, it dips. That is the week that I walked faster to see if speed also improved. Obviously it did not. It jumps back after the recovery from it. The improvement then fades in the 3rd week of July and the amount of activities steadily declines. This period includes the post-exertional sickness of 4 days after walking 3 miles on 7/23.  It then comes back up after the 2nd week of August.

More important than the increased activity is the number of times I got sick. This is how it used to look and how it looks now:

Basically, I've gotten sick only once since June 13. That is an incredible change given that I used to get sick at least once a week as shown in red in the daily log on the left. The improvement not only brought ability to walk more, it also raised the tolerance to exertion, that I'm no longer hitting the ceiling, as long as I keep my walking speed in check.

To sum it up, the distance has increased almost twofold in June for some reason. But I still can't walk more than 2.5 miles, even at a slow speed with 3 breaks, and there is no discernible improvement in the walking speed.

Sympathetic and Parasympathetic Fatigue

Since I got Polar H7, I decided to look into the heart rate variability (HRV) and see if it has any correlation to fatigue. I only got 2 weeks worth of data so far, so I can't write it up yet. I'll do that when I have at least 1 month's worth of data. But the topic of sympathetic and anti-sympathetic fatigue popped in the process of looking into it. Various exercise training sites and HRV apps claim that low HRV correlates to stress/deconditioning while the high value corresponds to exercise-induced fatigue.

According to this theory, the stress/deconditioning fatigue requires active recovery (exercise) while exercise-induced fatigue requires rest to recover from it. Sympathetic nerve dominates during the former and HRV plummets. Conversely, Parasympathetic nerve takes over during the latter and HRV goes up. When I came across an article about sympathetic vs parasympathetic overtraining syndrome years ago while researching OTS, I didn't quite understand it. Now they all fit together, at least in theory.

Healthy individuals experience fatigue when deconditioned or mentally stressed. This fatigue is alleviated by exercise. The body goes into parasympathetic dominated mode while trying to recover from exercise and the CNS balance is restored with the rest:

1 - Normal Fatigue Curve

CFS patients, on the other hand, don't get such relief. They are perennially in sympathetic fatigue state and they cannot exercise enough to produce exercise-induced fatigue because they reach the post-exertional sickness threshold of CFS well before they can reach the exercise threshold. Therefore the exercise triggers post-exertional sickness instead, making the CFS fatigue worse:

2 - CFS Fatigue Curve

Competitive athletes reaches their exercise limit first. If they continue to push without adequate recovery, however, they can reach the over-training threshold and end up with OTS fatigue:

3- OTS Fatigue Curve

Notice the similarity of this curve to the CFS fatigue curve. The difference is that, in case of OTS, the over-training threshold is above the exercise limit while the post-exertional sickness threshold for CFS is below the exercise limit.  Post-exertional sickness can be viewed as the overtraining syndrome for CFS patients in this sense, except that it gets triggered much easier because its threshold is well below the exercise limit.

Until recently, my fatigue followed the CFS fatigue curve. I'd keel over whenever I walk more than 2km or walk just a little bit faster. But that has changed for some reason since July. Now I can walk 2 miles without getting sick. The morning after the walk, I am getting the post-exercise fatigue that I recover from rather than plunging into post-exertional sickness. The graph now looks like this:

These fatigue curves are all theory of course, and I haven't seen any data to prove it. I'll write up some more when I have enough HRV data.  Even if my data confirms, it is a trial with only one patient for 30 or so observations. And obviously no randomization or blinding either. In other words, it still is no more than an anecdote. But it seems like a nice model to visualize CFS vs normal fatigue, regardless.