Oct 272015
Nutrition for a 100 miler

Salt – do we really need it ?

The ability to measure our sodium losses in sweat during exercise has led some to thinking that we need to replace at least some of what we lose in sweat to ensure our blood sodium levels don’t fall to levels that effect performance or health.

The thinking goes that somewhere between 230-1700mg of sodium can be lost per hour during exercise in hot conditions and we have a typical daily intake of 4g. As a consequence it can take only 2-3 hours before we deplete our sodium stores levels that effect performance. But measuring sweat sodium levels is only part of the picture – our body doesn’t particularly care what our sweat sodium concentration is (and in fact it reduces sweat sodium concentration as it acclimatises to exercising in the heat). What the body very tightly controls is our blood sodium levels and has several mechanisms to keep it within 135-145 mmol/litre range that is required for normal human function.

One thing to understand is its not the actual amount of sodium in our body that is the critical factor, its the concentration of sodium in our blood. If there is less blood then we need less sodium to keep the concentration in normal range.

Deciding we need sodium supplementation based solely on what we sweat out is like basing fat consumption based purely on how much fat we burn during exercise or basing our hydration strategy purely on how much weight we lose or our carb intake on how much energy we burn when we run. What we burn or sweat out doesn’t matter – its whats left in the body that we need to be concerned about. So when we look at fat burnt during exercise we know that we have ample supplies of fat so there is no need to take on additional fat, we know that our carb supplies will eventually run out so we need to take in additional carbs in a race but we know we don’t have to replace the whole amount we burn, we also know that the body can handle a certain level of dehydration with no adverse effects provided we drink to thirst. As far as sodium goes what we should be looking at is what happens to our blood sodium levels during exercise NOT how much sodium we lose in sweat.

Do we need to replace all of our sodium sweat losses, some of them or none of them?

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Sep 052014

Rinjanie finish 2

One day after Catherine and I had decided to spend a month or two in Bali between relocating within Australia Catherine stumbled upon a photo on Instagram that mentioned the Mt Rinjani Ultra. A check of dates confirmed we would be in Bali when the race was on and I quickly decided that if there was an ultra nearby then it would be criminal not to do it.

I was slightly disappointed when reading it was only 52km but then intrigued that the winning time last year was just under 15 hours. Ok it had 5800m of vert and went to an altitude of 3720m but even still 14 hours? I was in for a shock and the most testing race of my ultra career! Continue reading »

Jun 132014

Does your body or your mind limit your race day performance?

Mind over matter. Signage before the last big climb of the Yurrebilla Trail Ultra

Mind over matter. Signage before the last big climb of the Yurrebilla Trail Ultra

We all know that dead feeling in our legs, the feeling of complete physical exhaustion. Mentally we could keep going but our body is saying no more. Or is it?

The latest thinking is that the mind controls fatigue much more than the body. Continue reading »

May 232013

Not a bad way to spend a weekend

Not a bad way to spend a weekend

What is the difference between the elite runner and the back of pack runner? Is it fitness, training, genetics, mental or some other factor?

A few weeks ago I spent the weekend watching over 1000 runners compete in Australia’s biggest ultratrail event – The North Face 100 – held in the Blue Mountains west of Sydney. Apart from supporting the runners I coach who were competing and enjoying the atmosphere I was also looking for the differences between the faster and slower runners. I was keen to see if I could find any areas of improvement for the slower runners that didn’t involve any extra training time. Time is a factor for many athletes and whilst the elites tend to prioritise training above most other aspects of their lives the rest of us have other commitments that often restrict the amount of running we can do. Many of us are also limited by how much training our body can cope with before it breaks down. So is there a way to improve performance without any extra training time? Continue reading »

Mar 182013

Photo by Stefica Key

Photo by Stefica Key

The long run is obviously the most important training session of the week for an ultra runner but how long should it be?

I was initially of the opinion that longer was better but after building up to a long run of 75km before my first ultra and dying big time in the race I re-evaluated my ideas.

For my second race my longest run was only 45k and it was run at a much slower pace than my previous long runs. This was a resounding success as I was still running strong with 95 miles of running in my legs.

Why the big difference and why did running less ks at a slower speed in long training runs result in me running more ks at a faster speed during the race?

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