16 August 2012

There's a plan?

Back again, after another long hiatus. As you can see from the strava entries, this time it's not just from the blog, but from the bike as well.

Lots of things have been going on in the background, but as far as the riding is concerned, I've been pretty unhappy with how some things have turned out (or, not, as in my weight loss).

I have been dropping calories galore, and my diet has changed (not as completely as it will eventually; I take the food changes more slowly than the rest of it. Digestively, I think this is saner for my body and my compatriots). I'd been doing 1000 KCal + workouts several times a week (3+ for a while there), and the pounds just would not budge. I'll admit, I got kinda depressed about it.

But I've had a chance to think, and get away from the bike for a bit, and I think I have a partial solution. Also I've been reading up a bit more on both the Carmichael Training Systems' (CTS) Time Crunched Cyclist (or TCC) as well as Joe Friel's The Cyclist's Training Bible ( or CTB), in addition to some independent research on skeletal muscle physiology and some other research on endurance sport training, and I've been working too hard.

Specifically, although my HR Zones are based on a pretty solid time trial effort, I think my workouts are too hard by quite a lot. I'm routinely pushing my Zone 3 and borderline Zone 4 even during long workouts, and I think it's 1) overtraining me as a human, and 2) forcing the wrong adaptations for what I want to change.

For me, this whole process is first, and most importantly, about getting to a healthy weight. In doing that, I've been pushing harder than I should, I think, and training my muscles improperly for that purpose.

There seems to be a lot of debate in the exercise community about effort, and the current prevailing opinion of much of the media outlets (Rodale, for example, who publishes Men's Health as well as Bicycling Magazine, is big into putting people who espouse this line of thinking into their magazines) is that short bursts of high effort intervals with short recoveries, done in a relatively short workout, is the best way to lose weight.

I say balderdash. (Before you write me hate mail, let me say that intervals have a place in an overall workout plan, and are a very good tool both for getting through plateaus in workouts, and for switching stressors. But I digress.)

The basic line of thinking is this: running for twenty minutes burns more calories than walking for twenty minutes. This is true. Running for two hours, and walking for two hours, they do not have anywhere near the same caloric load, and you will burn more calories running for 120 minutes than walking for the same amount of time. Since more calories burned is better, the higher intensity should be the right way to go. So they advocate the high-low interval as a fundamental weight-loss tool, with the idea that doing a half-hour(ish) workout of 30-60 second high-intensity (80-90% of max) with 60-90 seconds of recovery eight, ten, twelve times with a warmup and warmdown will be a better overall calorie burn than a steady-state workout at the low intensity of the same duration. And in that respect, they are correct.

The problem isn't the calorie load, it's that the energy-generation system, and the recovery afterward, are all wrong. High-effort output of any kind is going to tap either the anaerobic energy production systems, or will tap primarily muscle glycogen stores aerobically (this will depend on whether the interval takes you into anaerobic metabolism, or merely pushes you to the top end of your aerobic system). Muscle glycogen is used in both of these systems, of course, although the first few seconds of a 90% effort interval may hit up the creatine phosphate shuttle.

But, this trains the wrong kind of body response for long-term weight loss. When your muscles start to drain their glycogen stores, they signal for replacements. Because of the ongoing high-stress demand, the body doesn't liberate fat through β-oxidation of fatty acids; instead, it liberates liver glycogen into glucose and dumps sugar into the muscles. This then creates a cycle that trains your body to be more efficient in glycolysis (and glycogenesis), and more efficient in storing liver glycogen. Which is fine as far as it goes, but unlikely to have much effect on weight loss.

The only way to convince the body that the best tool for the job of creating ATP to replace that used in the muscles is through lipolysis is by keeping the demand low, and going for long periods of time. When the stress levels are kept lower, but still high enough to tap into muscle glycogen stores, the body responds by oxidizing fatty acids for fuel. This, in turn trains the body to burn fat preferentially, and the more efficient the body is at liberating fat, the higher the heart rate can go and still be in a primarily fat-burning metabolism.

So, what I have been doing has been going way too hard for what I need to accomplish: get better at burning fat, burn primarily fat during the majority of any cycle workout, and save the interval workouts (which do have a place) for later.

With that in mind, what are intervals good for? Well, they absolutely shorten workouts. It is definitely possible to burn more calories in a shorter amount of time with an interval workout. Different kinds of intervals will help develop different kinds of adaptations. For example, the CTS Steady State (SS) intervals are very good tool for improving performance at the Lactate Threshold. This interval is done for relatively long periods of time near the LT power or HR threshold, but just below it, and trains the body to deal with high levels of lactate, with a short-ish recovery period, followed by another interval. The TCC SS intervals call for several of these intervals, with a recovery period of about half of the interval itself, during a workout. This workout would be done just a couple of days a week, because it's a high-stress workout. There are lots of other examples.

In any case, what I'm advocating here, though mostly for myself as a tool to focus on the weight loss, is the low-power, low-HR, long workout, focusing on forcing fat burning and teaching my body to burn fat preferentially. And until I get that done, there's little reason for me to do more than the occasional high-intensity effort, in order to shock the system a little from time to time.

So, what's the plan, then? Long, slow rides five days out of every nine (I am still working a 3/4 shift schedule, so I have to modify my timing to accomodate that), of probably 2.5-3.5 hours each ride. By slow, I mean just above the Zone 2 line of my HR (at the moment, roughly 146 BPM, though I think maybe keeping it around 140-148 is probably a good guide). Continuing to monitor the on-bike intake, and continue to limit the use of the gels and blocks (GU Chomps, btw, are really good after about the third hour). Keep up with the food changes (which I haven't gone over yet, but I've done a lot more home cooking. I bought the Food Zone Cookbook by Biju Thomas and Dr. Allen Lim, which I will review here in the next few days). Check back in a couple of weeks and see how the body feels, and whether the clothes fit any better. Re-evaluate.

So that's the plan.