Time trials and errors

There are no shortages of warnings coming from experienced triathletes warning against making last-minute changes to your training or race plan. Way to state the obvious, I thought. Granted, I used my biggest race of the year last year to break in my new bike, but I knew what I was getting into (somewhat). I couldn’t understand why anyone would use the last few weeks before a race to try something different, when they know what they’ve been doing so far has been working for them. This week I have a much better idea of how that can happen.

It started while preparing the nutrition for my long rides the last two weekends. I’ve never had any issues with nutrition on long rides before. I just bring a lot of Perpetuem or Sustained Energy powder, drink it as I’m thirsty, and I eat whatever I feel like whenever I get hungry. It’s pretty simple, and it works well. I take anywhere from 100 calories per hour to 350, ranging from almost pure carbohydrate to mixes of everything.

What got me worried was reading about everyone else’s nutrition requirements. Most athletes (or at least it seems like most athletes because of how vocal they are about it) have very specific nutrition requirements. I went to check out the sites of nutrition companies, and even their recommendations vary hugely. I was left with more questions than when I started.

How many calories do you require per hour?
How much sodium do you need?
How much do you hydrate?
How well will you handle other foods?

None of the recommendations gave a definitive answer. You just have to rely on trial and error. So basically after all that I just went back to my previous long rides (thankfully I had detailed nutrition logs), and estimated what I would need based on that.

The end result of all that research? Keep doing what you’ve been doing.

After those rides, I noticed that my heart rate was much lower than it was expected to be. I’ve been using 167 bpm as my threshold heart rate, which I used to base all my heart rate zones on. Basically your threshold heart rate is the maximum heart rate that is sustainable for one hour of exercise. They are usually different per sport. For swimming it’s not practical to use heart rate, so instead you use pace times. I use a 1000m time trial, and use that to grade the effort of all my training swims.

Using 167 as a threshold rate, that would mean that the upper limit that I should allow my heart rate to go would be the top of zone 2, which would be 161 bpm. But while I was on my rides, I felt like about 135 was my upper limit. If I pushed above that heart rate, I would feel burning, and get tired quickly. Something wasn’t right. I continued my rides based on how I felt, and based my target heart rates based on that. So I would try to keep it around 130, and occasionally push to 135-140 on hills. It worked well for me, but I was very confused how there could be that much of a drop.

After attending one of his seminars on Ironman nutrition, I contacted Nigel from NRG to look into getting some proper instrumented lactate threshold testing done. He was very helpful in calming me down. I know that I should just continue as things are, but I just needed someone else to say so. He told me that waiting until after I’ve recovered from Ironman St. George would be the best time, and after I’m a couple weeks into my first or second build cycle after. That helped a lot. But I was still curious on whether my heart rate zones would have changed or not. I thought your lactate threshold was supposed to go up when your fitness increased, not down!

Googling for information wasn’t very successful. That’s a pretty difficult search term to come up with, so I asked Slowtwitch for their thoughts on the subject. The first handful posts were very helpful, then it turned into a big debate about whether training above threshold is beneficial or whether it would inhibit aerobic capacity. In other words: will training hard make your endurance better or worse? Still very helpful, and a lot to think about, but not necessarily helping to clear my mind.

My semi-automatically-generated TrainingPeaks training plan programs one time trial for each sport on recovery weeks. I’ve never actually done them on previous recovery weeks, but I figured this would be a great opportunity. Nigel mentioned that recovery weeks aren’t the best time to do testing, but I was scheduled to do them anyway, so I figured I’d give them a shot. Maybe they would be enough to make sense of this all.

It turned out that I killed every benchmark that I attempted. First Ayesha scheduled a surprise 50m and 400m swim benchmark for Wednesday. Great timing! My previous best 50m time was 37 seconds. I’ve done it three times, but I’ve never been able to beat that. This time not only did I do it in 36 seconds, but I didn’t feel like I was going to puke after.

This set me up well for my 400m benchmark. I started off a bit too fast (trying to keep up with someone in the lane beside me), and I ended up getting passed by a lane mate. That held me up for six seconds (wow, I really like my Garmin for lap-by-lap reports), but I was able to draft off him for the rest of the session. Did that affect my times? Yes, absolutely. But I’ll go with it. He was very consistent, and he was actually lapping at a slower pace than I was doing before he passed. So we must have both drafted off each other. My final time was 6:50, which was two seconds faster than my best. I’ll take it—I know I can reproduce that, I just need to be more consistent.

Those didn’t do anything to change my swim threshold (since I use a 1000m benchmark for that), but they helped boost my confidence (the lack of which has been causing me to scramble for last-minute changes to my race plan).

Next was 5k run time trial. This was actually scheduled to be a tempo time trial. Based on my previous threshold heart rate (which was 177 (!?!)), that meant that I was supposed to maintain a steady heart rate of 167-169. It turned out that it was pretty much impossible to maintain. I ended up just pushing as hard as I could for the full 5k, trying to get as close as I could. Effectively it was a full-out 5k time trial. So I was able to use that number as my new threshold heart rate, which was 161 (the average over 5k) divided by 1.02: 158!

I revised my previous runs using this new rate, and it seems to make a lot more sense.

Last night was my 30-minute bike time trial. I went down to Cherry Beach, which is absolutely flat, and did one 7k lap to warm up, then pushed as hard as I could for 30 minutes. I estimated I would be able to get just over two laps done. I nearly finished three! I covered 12.43 km for an average speed of 34.4. Wow! End result was that my heart rate average over the last 20 minutes was 161—the same as it was for my run!

After revising my previous rides with these new heart rate zones, it shows that I was actually properly pacing myself during my 180k rides. Until I get proper testing done, it looks like I’ve got some decent zones to work with.

This morning I was scheduled for my 1000m TT in the pool. It was busier than I would have liked, and I didn’t get enough time to properly warm up, but I still pulled in my best 1000m benchmark yet: 18:18, which beat my previous best by three seconds. Not a huge margin, but considering the conditions I’m very happy with that. Not to mention this is in a 50m pool, compared to the 25m pool where I set my previous benchmark. That’s worth a few seconds a lap! This also changes my new threshold pace to 1:49 from the 1:50 that I’ve been using. Yes, its only one second, but it definitely counts.

So what am I to take from all this? Keep doing what you’ve been doing. Keep listening to your body. Keep pushing on. This is going to be a good race, and if you try and make any changes now, you’re just going to end up screwing yourself up.

Update: Sunday I hopped in for another TT—this time a 2000m swim in the 25m pool. My time was exactly double what my 1000m was the day before: 36:36! This means that this week I’ve beaten every previous time I’ve done, other than my 100m swim benchmark. Awesome week.