Heart rate and power

Heart rate and power, originally uploaded by samwebster.

Here is an example of why I think it’s helpful to know both heart rate and power. Here’s a screenshot of a part of today’s ride, climbing the main hill.

You can see that heart rate rises early in the climb and continues to increase as the climb progresses. You can also see that with each steeper section I’m able to put out a decent amount of power to a certain point. After that point each power peak is smaller and smaller, yet my heart rate stays very high (unusually high). I’m putting in a high level of effort but my legs are unable to continue putting out high levels of power. They’re done in.

This makes sense of course, because I’ve not been doing any aerobic training for the last six weeks that I’ve been in plaster and my legs have “detrained”.

My point is that without the heart rate data I would have been wondering if I truly had been putting in a decent effort. The power data is obviously useful.

By repeating this session I’ll be able to see in the data if my fitness is improving. Good, eh?

Neuroscience podcast no. 3 – Neurotransmitters

Neuroscience podcast
Phil tried really hard to teach me about neurotransmitters in our most recent podcast. We talked about how they work and went through a list of the key neurotransmitters and gave an overview of what they do. Many of them will be talked about in more detail in future podcasts!
My poor brain.
MP3: Neuroscience podcast – No.3 Neurotransmitters.
iTunes: Neuroscience podcast – No.3 Neurotransmitters (iTunes).

Cast off

46 days post-fracture and I had the fibreglass cast cut off my left leg today, and my foot and its x-ray images examined. All seems good (although the callus looks messy on the x-ray – it would be great to look at the same bone in 12 months time to see the remodelling).
Notes from today:
– when the nurse took the cast off my ankle was shockingly weak. I had to be wheeled to x-ray and back. Very weird.
– an hour and a half later (after lots of wiggling and some cautious standing) I was able to carry Annabel upstairs at home, so rapid improvement.
– the bone is very superficial so I can just about palpate the fracture. There’s no pain here.
As expected I’ve lost a lot of ankle strength and mobility, and my left calf is noticeably smaller than my right calf. I’ll try to meet up with my sports therapist to get it assessed and a rehabilitation programme sorted out. I rode my fixie to the pool today in pouring rain and the ankle was fine. The ankle felt horrible in the pool but everything else was pretty much OK. Weak and weird.


41 days of healing. I walked 3km or so with Annabel with no pain in the area of the repairing bone today. At about a kilometre I had a dull sensation in the region of the fracture that quickly faded. After that the only discomfort was from the cast flexing and crushing my toes and banging against my heel.
I’ve been walking for 20-45 minutes 2 or 3 times a week for the last few weeks and the foot has been feeling fine. My consultant said the pain would let me know when I was doing too much. We all know how important mechanical loading is to bone functional adaptation, right?

Week 6 in plaster

Still In PlasterI’m finally into my 6th and hopefully final week in plaster. My foot is feeling really solid still, and the only discomfort I’m getting is from the plaster cast flexing and squashing my toes and banging against my heels. Walking is still a bit of a hobble because the cast prevents any ankle movement and almost reaches my knee, making it impossible to fully flex the knee. The cast itself is starting to break down under the ball of the foot in thin areas, allowing it to flex where previously it was stiff.
A bus driver stopped at a pedestrian crossing to let a couple cross but was still looking at something in his cab when he accelerated towards me yesterday. He hadn’t looked up and was only paying attention to the people he had seen out of the corner of his eye, so I had to hobble and shuffle quickly out of the way of the bloody thing and it’s not easy to accelerate in a cast. It was a reflex reaction and my brain had briefly forgotten I was wearing the cast so my movement wasn’t great. There wasn’t any pain from the fracture area but the cast banging into bits of me and causing my knee to lock straight was uncomfortable and made me wince. The idea of getting run over by a bus at 5mph probably made me wince more.
I’m getting a little used to this free time, and starting to wonder how I’ll adapt to going back to training next week. It’s probably a good job that I entered all those races this spring and summer or I might have become a little lazier and not so keen to get out there every day, weather be damned. Upcoming races are a kick up the arse, excuse in hand (foot) or not. It feels like those lovely chemical rewards my drug-dealing brain got me hooked on for running, cycling and swimming every day are starting to wear off and I’m wondering why the hell I trained as much and as hard as I did. Make a plan, stick to the plan, get out the door, feel the opioids. I did cane it in the gym today so my worries are probably unfounded.
I’ve also been wondering if my attitude will change. Up until now I’ve been pretty indestructible. I was never a nutter rock climbing but I used to be able to put my head in a good place early in the season and climb some interesting stuff. I used to revel in the interesting stuff, but would maybe cack it a bit if I was pushing both my grade and the risk. But then I guess that’s the point. Controlling the cack it factor. For a period I was making an average of one stupid potentially fatal mistake per year but survived, never really hurt myself (even when belayers didn’t catch me!) and learnt from those mistakes. Indestructible. When Kim became pregnant with Jack something in my brain changed and I was never willing to climb as risky as before. Make of that what you will.
As I get older I get a little more sensible. Like the potentially fatal climbing errors I’ve learnt from I’ve also learnt to avoid the really icy roads, to ride straight, tall & slow (but don’t brake!) through icy patches on the bike, and to not hammer it down greasy descents in the drizzle. Now that I’ve broken a bone and experienced the repair, the loss of fitness and the inconveniences, and have yet to even start the rehabilitation, will I become even more careful? To the point of losing time to competitors? Maybe I’m still indestructible. I feel like I’m healing quickly.

Anatomy: the orbit & superior orbital fissure

On Monday we went through the bones of the orbit, what the superior orbital fissure (and inferior orbital fissure and optic canal) were, and what went through it (and them).
To review the bones of the orbit look at these images. Hover over the bones to be reminded of their names. We also noted that the palatine bones just about reach up to the orbit, but you can’t see this on the images.
Inferior Orbital Fissure
The superior orbital fissure is the slit in the posterior wall of the orbit. It passes through to the middle cranial fossa within the cranial cavity. The inferior orbital fissure is the slit in the floor of the orbit passing to the infratemporal fossa.
The superior orbital fissure is the main route for stuff to get from the brain to the orbit then. Everything in the orbit (muscles, glands, mucosa, skin, etc) will need to receive nerve fibres from cranial nerves passing through the superior orbital fissure. The optic nerve and the retina are the exceptions to this.
With regards to blood supply though, the ophthalmic artery passes through the optic canal with the optic nerve. It is a branch from the internal carotid artery and sends arterial branches out and around the orbit. The ophthalmic veins (there are superior and inferior opthalmic veins) do pass through the orbital fissures. Maybe a little counterintuitively the superior ophthalmic vein drains blood from the orbit back into the cranial cavity by passing through the superior orbital fissure. (The venous blood passes to the cavernous sinus on the other side and eventually leaves the cranial cavity through the internal jugular vein). This gives a route by which infection or drugs can pass intracranially from superficial structures, and will no doubt be mentioned a number of times in your studies. The inferior opthalmic vein connects to the pterygoid venous plexus of the face by sending branches through the inferior orbital fissure.
So what nerves pass through the superior orbital fissure? In essence, cranial nerves III, IV, V and VI. Easy, eh? Well, there’s a little more detail to it that you need to know.
Also known as the oculomotor nerve, this sends fibres to almost all of the muscles in the orbit (both extra-ocular and intra-ocular, i.e. the muscles of the lense and the constrictor muscle of the iris). It divides into superior and inferior branches before it emerges from the superior orbital fissure.
Also known as the trochlear nerve (trochlea comes from the Greek word for “pulley”, and this is the nerve to a muscle that has a pulley) this is another motor nerve with the singular task of innervating the superior oblique muscle.
Here things get a little more complicated. Cranial nerve V is the trigeminal nerve, which divides into 3 branches within the cranial cavity: V1 (ophthalmic nerve), V2 (maxillary nerve) and V3 (mandibular nerve). These are the sensory nerves of the face (although you’ll remember that the mandibular nerve also sends some motor fibres to the muscles of mastication) and we’re interested in the ophthalmic nerve when we look at the orbit. Just before the ophthalmic nerve enters the superior orbital fissure it divides into 3 smaller nerves:
frontal branch
lacrimal branch
nasociliary branch
So that’s a little inconvenient and tricky to remember. Note that some of these branches are rather interesting in function and in the other nerve fibres that they pick up that are not from the trigeminal nerve, but I won’t talk about that here.
Last of all we have the abducent nerve (or abducens, whichever you prefer). The name of this nerve comes from its ability to abduct the eye, as it sends motor fibres to the lateral rectus muscle.
That’s about it for structures passing through the superior orbital fissure. Make sure that you can link all this up with what you learnt about the other parts of the orbit and the eye, and what you will learn about the functions of those structures.

5 weeks in plaster

Walking With A Stick
I’ve done 5 weeks in plaster now. That’s 35 days in a cast from my toes to my knee on my left leg. From the end of week 4 the foot started to feel really solid again with no pain. I can sometimes wiggle it and find an interesting sensation, like probing a painful tooth with your tongue, but that’s about all. Looking back through my tweets I see that I was predicted to not be walking without pain until 8 weeks or so, so that’s encouraging. An orthopaedic colleague suggests I will be in trainers for a while when the plaster comes off, and that’s fine with me. With walking and some work in the gym the strength and fitness of the quadriceps and hamstring muscles in my left leg have started to match that of my right leg agan already. Some of the work I’ve been doing in the gym has strengthened pre-existing weaknesses in my hip and core muscles to also better balance between left and right sides.
After periods of going nuts I’m starting to enter a new phase. Thanks to international adventure racing 1st year student star “Jacket” John Laughlin and a pile of inspiring DVDs he lent me my brain is feeling a bit better. But with 5 weeks of, essentially, sitting on my arse I’m falling back into that phase of, “do I really want to train every day for hours & hours”? My new found laziness is suggesting I take it easy. Swim every day? Are you mad? You want to go out on the bike for how long? Why? Part of my brain is sounding like normal people. I try to avoid being normal (normal is another word for “average”). If it’s wet and cold when my plaster comes off I may have to push hard to get myself outside. But I doubt it. I’ll lay down a plan and follow it, measure progress, and find out where the pain is.
I’m back in fracture clinic a week on Tuesday. I’ll look after myself for 11 more days and hopefully my consultant will tell me I’m good to go. When I leave the care of the wonderful NHS I’ll surround myself with the continued care of the University Sports Village and get myself back to form. That’s half the fun.

How busy?

Heel RaisesYou never realise how much you do until you stop. This seems to be particularly true of training.
Skills swims, endurance swims, long runs, 800m track intervals, ME swims, easy bikes, cruise intervals, hilly bikes, long bikes, tempo runs, sea swims, maximum strength sessions, massage and foam rollers. When you stop all that a huge amount of time appears in your week. Not that you fill it with much. You kind of sit around a bit wondering what you should be doing. Is it only 9pm? What do I do now?
With a broken bone I guess I spend a fair bit more time sleeping (good for recovery and repair, lie-ins and early nights). I spend more time looking for things to read. I spent the first 3 weeks seriously levelling World of Warcraft characters (funnily, I want to spend more time in dungeons with a couple of them but those need 2-3 hour dedicated time slots and I’m now struggling to find any of those). I’ve been getting a bit of writing done, and I have more time to get work done in, but without the break part way through the day for training I find I’m a bit worn out by the mid-afternoon. So my productivity hasn’t changed.
I’ve spent more time at home because I can’t get myself about by bike or by car (would I be able to if I had an automatic?) So I rely on the generosity of others to get me to work and back. It has been great to spend a lot of time with Annabel (who has now climbed onto my chair and is hanging over my computer) and to see Jack when he gets home from school. Morning’s haven’t changed much. I’m not up at 6 and out the door as they wake any more, but everyone’s in such a rush it’s not much different.
I’ve got just under 2 weeks until my next fracture clinic appointment, at which I hope to be declared fairly fit and to have the plaster removed. The foot feels strong this week and there’s no pain on walking or weighting it. I wouldn’t like to go trampolining just yet though. I’ll entertain myself for a bit by re-planning my training for 2010 in TrainingPeaks.com.

Neuroscience podcast no. 2

Another neuroscience podcast is out: Phil tells me why my weight is fairly stable, what happens in my brain when I get hungry and what changes when I have eaten. We talk about the adipostat, leptin, ghrelin and obesity, why we choose particular foods and how dopamine, opioids and (probably) serotonin are involved.
MP3: Neuroscience podcast – No.2 Neurobiology of appetite regulation.
iTunes: Neuroscience podcast – No.2 Neurobiology of appetite regulation (iTunes).