Caffeine

by Derek Morrison

N.B. Read in conjunction with ‘Espresso Delivery‘
(VeloScience, 5 February 2015).

In every coffee bean
Lies a variable dose of caffeine
Which blocks your adenosine
Thus raising your catecholamine.

With adenosine you can’t tell
But it’s present in every cell
It chills things down, makes you less aroused
You feel its effects whenever you’ve drowsed.

Catecholamines are for fight or flight
But they can make you feel real uptight
Adrenaline is one, that makes you act
From every day frights we know this fact.

With caffeine our cerebral vessels constrict
But you will still feel that you have it licked
In fact you may feel deceptively fitter
It affects more than one neurotransmitter.

Time to exhaustion can improve by a large amount
Nearly 15 percent by the last count
Sprinters and weightlifters need not apply
Slow twitchers is where the advantages lie.

As potassium falls within the cell
It rises in the blood which rings the bell
That muscle fatigue has just got pending
And lest you stop it will force an ending.

But caffeine improves the cell pump
So your electrolytes don’t get the hump
Thus blood potassium it decreases
And all muscle cell activity it increases.

Heart muscle should always respond to action
But caffeine ups its force of contraction
And when it comes to your heart’s rate
Like blood pressure, caffeine can it elevate.

There’s debate about caffeine’s role with fat
Stimulating energy expenditure from that
But fat oxidation is more likely with endurance
Fast twitch muscle activity provides no such assurance.

And your need to pee may make you strained
Because sodium and water are less retained
But with time your body may adjust
So that this becomes much less of a must.

In theory caffeine could your airways dilate
So that your lungs can better inflate
But for that the dose would need to be high
And so for that effect let’s not try

So caffeine is a powerful drug
That you put daily into your coffee mug
It’s a psychoactive in a common bean
With some of the effects of amphetamine.

[To listen to this verse select below]

I’m the bridge of two rivers
The Severn and Wye
I’m seen from a distance
My two towers in the sky.
I’m the bridge of two countries
England and Wales
Offering a gateway
To many new trails.
I’m the bridge of two pathways
For feet and pedaled wheel
Most know only of one
From England right they peel.

Severn Bridge cycle path — *Old Severn Bridge, cycle and walkway*

I’m the bridge with two views
Not enjoyed from the M48
But you who can stop
Please do contemplate.

*Animated panorama from the Old Severn Bridge viewed down the estuary towards the new Severn Crossing, Severn Beach, and Avonmouth.*

Old Severn Crossing - reflection — *A moment of reflection on the old Severn Crossing viewed up the estuary towards Berkeley. The decommissioned Oldbury Nuclear Power Station is visible in the distance.*

I’m the bridge of bygone fission
Easily visible as you ride
Oldbury Nuclear Station
Lying just beneath one side.

*Oldbury Nuclear Power Station (decommissioned 2012)*

I’m the bridge of destinations
For pedalers to explore
Chepstow as a first stop
Right through Wales’ door.
I’m the bridge to border country
Wales and England you can weave
A glorious descent of Wye Valley
Comes before Brockweir heave.

*Descending the Wye Valley on the A466 towards Tintern.*

*Brockweir Bridge crossing from Wales to England near Tintern*

Brockweir Cafe — *Brockweir Village Shop & Cafe at about a third of the way up a steep long hill*

*Old Wye Bridge, Chepstow Attribution: Andy Dolman [CC-BY-SA 2.0]*

I’m the bridge of many moods
I can be sunny, calm and serene
But given my position
My fogs and winds are mean.
I’m the bridge with two gates
One in England, one in Wales
Don’t get trapped on the ‘wrong’ side
Because they can be shut in gales.

Severn Bridge automatic gate — *Old Severn Crossing automatic gate*

I’m the bridge with listed status
Whose cables were feeling pain
So now my younger sibling
Relieves me of some strain.
I’m the bridge of two bridges
The Severn and the Wye
But most think we’re one
So invisible is our tie.