Wednesday, May 30, 2007

SIPE

A couple of weeks ago, I had a swim lesson at Aquatic Park, which is a swimming area in the San Francisco Bay. It was a warm sunny day, but the water was still cold. After warming up for a few minutes, we started with some intervals to practice open water pacing. After a fast interval lasting several minutes, I brought the intensity down to an easy level. Normally, I would start to recover right away after backing off on the pace; this time, I was struggling to get my breath back. I swam for several minutes more and did not improve. By the time the set was over, I could not swim another stroke.

Once I got out of the water, I started coughing profusely and spitting up slightly pinkish froth (sorry, a little gross). I definitely had fluid in my lungs, and felt severely short of breath. I could still walk and talk, and didn't feel like I was in any imminent danger, but the coughing did not let up; nor did the frothy spit. Weird! I had to go back to work after my lesson and continued to cough and feel very tired.

After doing some research, I identified the event as an episode of swimming-induced pulmonary edema, or SIPE, which has been infrequently reported in medical journals. My symptoms fit exactly with other described cases. Conditions which lead to SIPE have been described as cold, open water swimming or diving at high intensities. The thought is that the cold water in addition to the position of the body during swimming causes central pooling of blood; during intense swimming the pressure in the pulmonary capillaries becomes too great and fluid and some red blood cells (along with some other large proteins) break through to enter the alveolar sacs in the lung. Where there is water, no air will be exchanged so this is not a good state to be in!

I actually contacted the authors of one of the papers and we may work together to collect some more data on this condition, especially in triathletes. If it becomes severe enough, it can be fatal through drowning. I was surprised that no one in the triathlon community (with whom I have spoken) has ever heard of this, especially considering that we all swim in very cold water frequently, and may often try to swim fast. (Cold water and intense swimming are typical contributing factors.)

Fortunately, the condition seems to resolve within a week, and some careful physiological tests done in one study show that within a month, it is impossible to distinguish those who had it from those who didn't. I felt mostly better the next morning and completely better by the day after. I've been able to complete further swim workouts without any problems like that; although I still need to get back in the Bay to see how that goes. Fortunately, I won't be swimming as hard as I was in Coeur d'Alene, and the lake water temperature there is warmer than at Aquatic Park.

Thursday, May 17, 2007

In the Thick of It

Things are getting busy! Last weekend I completed my first 112-mile bike ride followed by an 18-mile run the next day. Both went well, and I was a bit surprised that my body seemed to hold up through the long workouts. We rode up in Napa along the Silverado Trail to Calistoga and back, twice. It's a great place to ride, since it's mostly flat or rolling, with very tame hills compared to what we usually ride. I used Perpetuem again, using 6 scoops (total of 162 g carbs and about 780 calories) for the whole ride and also ate about 1 gel per hour. I set my basal rates to my race day profile and programmed in a bolus for the Perpetuem. My BG's were riding a little high but I was able to keep them stable through the use of my Dexcom. My strategy this time was to eat when I saw it falling and then wait a bit as the BG started to rise. I need to go back and look at the numbers, and I should also download the data from the Dexcom.

I also used the Dexcom on the run the next day, and things went well. Maybe I will try and use the thing during the race, after all. I seem to have problems with it coming out of the swims, though, even when I use the shower patches, and I don't want to waste a lot of time fiddling around with it. I have a swim-bike workout this weekend so I'll try it out then.

Tuesday, May 08, 2007

Two Down

After making 6 trips up and down stairs from my apartment yesterday, I unpacked the car from a weekend of camping and racing down at Lake San Antonio, Monterey County, CA.

I had arrived Thursday morning to a mostly empty camping ground, and started to set up camp with a few other friends from my triathlon club. People trickled in on Thursday and then started to pour in Friday afternoon. This race draws people from both northern and southern California, and is definitely the largest triathlon event in California, and the second largest in the U.S. (behind the Chicago Triathlon I am told). There are 3 events: the long course (1.2-mile swim, 56-mile bike, 13.1-mile run), the mountain bike course (sprint), and the Olympic course (1.5-km swim, 40-km bike, 10-km run). I was racing the long course on Saturday. Everyone was watching the forecast. The weather had been mild all week but the wind gusts were strong enough to nearly blow away my tent until I put the stakes in.

Race Planning

I spent several hours on Friday planning my basal rates and nutrition for the race. I decided to set up a special race day basal rate profile, with rates that gradually decreased as the day went on. My race started at 9:15 and I estimated my swim time to be around 50 minutes. For my morning swims, my basal rate is usually 0.55 U/hr but I often reduce by 30% and eat a GU before swimming. Normally, at 9:15, my basal rate is 0.35 U/hr so I settled on a rate of 0.3 U/hr. I also calculated my average basal rate--0.3 U/hr--from my last 100-mile bike ride and set that as my basal rate for the first couple hours of my ride. From training experience, I've noticed that, after a long ride, once I start running, my BG's start dropping rapidly. I decided that I would try reducing my basal rate during the latter half of my ride to reduce the risk of dropping low on the run. I would continue to taper my basal rate throughout the expected duration of my run. Normally, during the run of a half-ironman triathlon, I end up turning my pump off completely; I was hoping that I could reduce the need for this.

I also planned to eat my normal pre-race breakfast of a banana and a Luna Bar about 3-4 hours before the race, and take most, if not all, of my normal bolus. Additionally, I would drink some Hammer Heed to keep myself hydrated, and eat one gel right before the swim start. I planned to drink 160 g carb's from Perpetuem on the ride, with an additional 2 gels as needed. I planned to take 1.9 U insulin for the Perpetuem over 3.5 hours, my expected ride time, in a 10% immediate, 90% extended delivery mode. For the run, I planned to eat about 4-6 gels. I would supplement with electrolyte caplets as conditions warranted. (I.e., for warmer weather I would take more.)

Race Day!

So here's what I actually did! Saturday morning, around 5:15, I woke up, and ate breakfast and dosed according to plan. My BG skyrocketed like it always does race morning, but this time I didn't panic. Well, not much, anyway. It's hard to completely ignore a BG of 414. I took a small correction of 0.5 U and waited it out. By the time my race was an hour away, my BG was bumping around just below 200. I was drinking Heed so it was fluctuating a bit. I reduced my basal rate by 30% because I felt that the BG was trending downward. About 20 minutes before my swim, I ate a Hammergel and drank up a bit. We headed down to the start, seen before the race in the above picture, and zipped up our wetsuits. Only then did I realize I had forgotten to put BodyGlide on my neck. I hurried back to my transition area and got back a minute or two before our wave started our 5-minute warmup. I stuffed my two GU's in my wetsuit sleeves and smoothed them down. Soon enough, we were off!

The water was warm by comparison with Aquatic Park in San Francisco, and I was comfortable. I was happy to be keeping up with some of the pack for some time at least, and was hoping that maybe I would have a faster swim split. I had been practicing my sighting and hoped to shave off some time by avoiding my meandering swimming ways. After we turned southward, I started thinking, "Why are they letting boats out here?" since it felt like we were swimming through wakes from speedboats. Only after the turnaround did I realize that those were actually swells! We were swimming directly into a strong wind and it felt more like an Alcatraz swim than a nice swim in a lake. The swim dragged on but I was at least making slow progress. I tried to keep my focus and to stay relaxed, and to not get too disturbed by the overly aggressive swimmers passing me by. (Now if I am not swimming close to the buoys is it really necessary to swim over me? Sheesh. I had to give one gentleman a gentle "nudge" when I got completely fed up.) I finished the swim in about 50 minutes, no faster than my last race, but still feeling fairly fresh.

I hustled into transition, seen in this photo (before the race), and got assembled for the bike. I was happy to not have to reconnect my pump; I did, however, program in my planned bolus for the Perpetuem. I decided to test my BG once I got going up the first hill, and was on my way.

My BG was 217 after about 10 minutes on the bike but I had my extended bolus going, so I wasn't worried. I also had revived the Dexcom for the race and had it in my Bento box. It was reading 100 so I decided to disregard it. I was disappointed because I was hoping it could be useful on the ride and run. Less than 30 minutes later, the Dexcom was alarming that I was below 55 mg/dL. Although I knew the absolute measurement was wrong, I decided that I would trust the downward trend and drank a bit more Perpetuem, but not more than I planned to eat per hour. An hour later, I was absolutely shocked when I measured my BG at 417. Yikes!! What was going on? I took 0.8 U of insulin and stopped drinking the Perpetuem. About 30 minutes later, my BG had gone up to 488! Ugh. I was not a happy camper. I really needed to keep eating in order to make it through the day, and I was getting worried that my pump was broken, that my insulin was bad, or that my infusion site was bad. I had 2 infusion sites prepared and switched to the other one (which was actually the older site that I hadn't been using for about 18 hours). I took another 1 U insulin and hoped that things would improve. Finally, in another 30 minutes, I was relieved to see a BG reading of 432. I decided to eat in another half hour or so when I felt a pang of hunger, which is a pretty reliable cue that my BG is dropping (or that I am just hungry!). I knew that I had a 1.8 U bolus plus another 1.9 U accumulating plus my regular basal rate, and felt slightly more confident (or at least hopeful) that my BG would continue to come down. After my first high reading, I had decided to back off on the pace; normally, I try to push myself pretty hard, but that would have to wait for another race.

I had only drunk half of my Perpetuem, and hadn't eaten any gels, by the end of the bike. I did eat half a banana around mile 50. I finished the ride, slid into my running shoes, and grabbed my fuel belt pack and visor. I was off! I tested my BG at 138, and was happy to have a soft landing from my BG woes on the bike. I tested at 116 twenty minutes later and ate some Sports Beans and some Sharkies (fruit snacks). I wasn't feeling so hot at this point, since having high BG seems to upset my digestion. Plus, I was probably a little dehydrated. A half-hour later, my BG was down to 99 and I ate a GU and a Hammergel. I also turned off my pump for an hour. I started feeling better at this point and didn't test for another 40 minutes, at which point I was 153. My basal rate of 0.05 U/hr resumed shortly thereafter and I tested at 136 thirty minutes later. I continued to eat gels occasionally and also made myself drink a full cup of Gatorade Endurance at each water stop (every mile). I finished the race in 7 hours, 3 minutes, with a BG of 167. Not too shabby, considering everything that had happened.

Lessons Learned
  • I should probably take more insulin at the beginning of my ride and use a bigger insulin:carb ratio. Taking a 30:70 extended bolus (instead of 10:90) might be a good idea if I plan to eat at the beginning of a ride. Also, maybe I could try increasing my basal rate a bit at the end of my swim or beginning of my ride.
  • I think having the tapered basal rate profile works well, although it's tough to know exactly how different conditions will affect how much insulin I need.
  • If my BG gets high, it is especially important to drink lots of fluids. I didn't take that into account and was probably fairly dehydrated by the end of the ride.
  • I usually pop up really high before the race. To avoid starting the race with a high BG, I should eat breakfast 4 hours beforehand, and take my normal bolus. A meal of 45 g carbs is good. If I go high, I shouldn't panic too much since it will most likely come down before the race.
  • I still need to figure out how to do the run without fighting off low BG the whole time. I am afraid of what would happen if my digestion slowed down for some reason.
The Wildflower Long Course was the 2nd triathlon I ever watched, and the one I swore I would never do! I was happy to have finished the race feeling strong, and without any need for medical care. People who had raced the course for many years agreed that this was one of the toughest years with the strong winds on the swim and bike, especially. Now that I have finished Oceanside and Wildflower, I only have one big triathlon left! I am excited to finish most of my preparations this month and to ease into a 3-week taper before the big day on June 24.

Tuesday, May 01, 2007

Don't Procrastinate

So last Saturday, I thought I would try out my new plan: use the 1:80 ins-to-carb ratio but take it over 3 hours instead of 4 or 4.5. Compared to my first 100-mile ride, I was effectively taking .45 U/hour last weekend instead of .65 U/hour in addition to my regular basal rate, and eating 36 g/hour instead of 47 g/hour. Hmm...this seems reasonable. After about 2 hours on my ride, I got low and actually had to stop riding to get my BG back up. I mean, I had to get off my bike completely. I tried just coasting and pedaling now and then (fortunately I was on flat road), but my body resisted.

Anyway, I can't really pinpoint what happened, except that I didn't supplement with any extra gels the first 2 hours, and I had felt a hunger pang that I ignored. And, I must not have been eating enough.

Okay, I think the real reason I went low is because I was on a rolling hill section with no stop signs or lights and I just hate stopping there. Plus, everyone would catch up and pass me if I did!! No fair! But I should have at the least pulled out a gel when I felt that hunger pang. Argh. Basically I got in trouble because I was procrastinating eating!

I think to simplify things in the future, I will try to manage my BGs with basal rates only, and no boluses. Maybe, then, I can have basal rates for hilly rides, flat rides, etc. I might also try to use the calorie count feature on my bike computer to estimate how much food + insulin I should be taking in. Maybe I should get a power meter for my bike; that could be insightful.

Other totally random things:
Gatorade upsets my stomach on long rides. So do PowerGels. But I really like the chocolate PowerGel (tastes like frosting) so I might eat them anyway. Hammergels are slower to absorb than GU's, which taste the best. ClifShots taste salty and don't help me pull out of a low easily (then again, I could blame the Symlin for that). Perpetuem is surprisingly filling, and helps to keep my BGs stable. It also goes down really well with a bit of water. Sharkies are really yummy and it's easiest if I put them in a ziploc before I ride. Ziplocs are handy for all sorts of other things, including my BG meter. I can test my BG while riding if I chose a spot with a slight incline and do things very slowly and carefully. I should also drink more water than I want to, and I will probably feel better than I would expect as a result.

Here's another picture from last year's Wildflower race. There are thousands of athletes who compete in these events. My race is on Saturday! Did I mention that already?