One circuit on Mount Alexander is when I’m wanting to practice all the decisions I make scrambling over rocks. The other is along undulating tracks and dirt roads through the bush in the Castlemaine Diggings area. Out and back it’s 15km and easy walking – only 400m of ascent then descent. With surfaces of low risk of falling and having done it many times, I don’t have to think, so it’s fast training.
I like setting out early so I can see it gradually get light and it’s cool, so on Saturday I set out at 6am. I didn’t feel great and was slow over the first lap of 15km with a pack of about 15kg, so I went home for lunch, took a long break. I removed my Dromedary ballast water bladder, repacked with equipment I’d use for a 3 day walk (got my pack down to 14kg) and went back for the second lap (I’d done two consecutive laps earlier in the week).
By the end of lap 2, I was feeling energetic and thought to myself I wonder how far I can go. I had a headlight with me so I took some other tracks to relieve the boredom and walked until it was dark. When I stopped, my GPS tracker said I had completed 40km in the 10.5 hours of walking time with 1500m of climbing. I’d drunk about 4 litres of water and I was tired but pleased. I had committed to walk 36km for the weekend and had finished in a day.
I had most of my dinner by about 8.30pm but before I could finish it I had to lie on the floor before I would have fallen off the chair. My wife took my pulse and was worried because it was 32 beats a minute – not what it should have been after a long day of walking.
By the time the ambulance arrived I was feeling both better and foolish. Although I’d drunk sufficient water on a warm day, I had neglected to take any electrolytes. I had no excuse not to know of this. As an Audax cyclist I have learned the hard way of failing to keep my electrolytes up on long rides but I hadn’t transferred that practice to bushwalking. Inexpensively for my cycling, I use what a doctor friend said was sufficient: a couple of magnesium tablets and half a salt tablet a couple of times on a full day ride. Snacks of dried bananas add the necessary potassium and some sugar.
The paramedics ran an ECG test and a blood sugar test on me, agreed that I didn’t have to go to hospital and said that the cause of my near fainting was most probably a vagus nerve attack (likely caused by the lack of electrolytes). The effect of lack of electrolytes can be sudden: one minute you’re OK, the next you’re about to faint...falling...head injury...?
Your vagus nerve is your friend. But the moral of this story is “Don’t trigger it into action”. Curb your enthusiasm. Just because 30km was good, 40km may not be good for you (or at least keep both water and electrolytes up to what your body needs).
Rob Reid Smith