Monday, 29 October 2018

Munga - Stop Hanging Around

In 2015 my average moving speed was 18.07 km/h. In 2017 that had marginally improved to 19.78 km/h but my overall race time had come down by 18 hours.

Remember that moving speed is calculated with all the stops stripped out. Every time you stop your overall speed comes down which means In 2017 I ended on an average race speed of 16 km/h.

A better picture emerges when we examine my speed between Race Villages which takes the conditions (heat, wind, tiredness and boredom) into account.

Bloem to Van der Kloof - 219 km- 22.46 km/h

Van der Kloof to Britstown -176 km - 22.3 km/h

Britstown to Loxton - 190 km - 13.01 km/h (extremely hot and windy and I felt like death warmed up)

Loxton to Sutherland 15.4 km/h (tired,4 power naps)

Sutherland to Ceres 14.4 km/h (hot, tired, 1 power nap)

Ceres to Wellington 21.4 km/h (tired, 1 power nap)

I rode fine all the way to Britstown and then battled with heat, wind and sleep monsters from there to the finish. It got particularly scruffy between Britstown and Sutherland.

The 2017 data shows that I was moving for 54h36 and only spent 6h22 in Race Villages— slept at Loxton and Sutherland. That means I spent 6h35 at water points, power napping, getting water from reservoirs or sitting next to the road feeing sorry for myself.

That's my data. Gavin Robinson—aka Mrs Robinson—crunched his data for 2017 and sent it on. His numbers are:
Total race time 98h18
Race Village time 16h46
Time not moving while between Race Villages (water points, power naps etc.) 18h30
Even though his overall race speed was only 10.9 km/h his average moving speed was 17 km/h.

I've developed a basic formula to figure out a total finishing time based on a number of parameters.

Total time in minutes =((1080/AMS) x 60) + (ARVT x 5) + (WPT x 10) + ((RVS + 60) x NRVS) + ((RSPN + 10) x NRPN)

AMS = Average Moving Speed (in km/h)
ARVT = Average Race Village Time (in minutes, excluding sleep)
WPT = Water Point Turnaround (in minutes)
NWP = Number of Water Points (default is 10)
RVS = Race Village Sleep (in minutes, I add 30 mins either side of this for shower and dressing)
NRVS Number of Race Village Sleeps
RPN = Roadside Power Nap (in minutes, I add 5 mins either side of this)
NRPN = Number of Roadside Power Naps

Let's populate that formula and see what pops out:

Assuming the following:
18 km/h average moving speed
15 mins per water point
30 mins per Race Village
2 Race Village sleeps of 180 mins each (3 hours)
2 roadside power naps of 45 mins each

Total time in minutes =((1080/18) x 60) + (30x 5) + (15 x 10) + ((180+ 60) x 2) + ((45 + 10) x 2)

3600 + 150 + 150 + 480 + 110 = 4490 minutes = 74 hours 50 mins

That's a reasonable finishing time.

Let's see how it might look for someone with ambitions to finish in the top 10.

Using the following:
20 km/h average moving speed
10 mins per water point
20 mins per Race Village
1 Race Village sleep of 90 mins
3 roadside power naps of 30 mins each

Total time in minutes =((1080/20) x 60) + (20x 5) + (10 x 10) + ((180+ 60) x 2) + ((45 + 10) x 2)

3240 + 100 + 100 + 150 + 120 = 3710 minutes = 61 hours 50 mins

I think that might just make it into the top 10 - I'll use that data for my own effort.

Spreadsheet racing is fun but often the reality is very different. It's a given that the mercury will get into the high 40's and we will experience prevailing head winds. Add tempestuous weather and your spreadsheet data won't be worth the iPad it's written on. Even so, it's worthwhile crunching the numbers to figure out what you might be capable of IF you don't waste excessive time doing stuff that's not beneficial. Remember that beneficial = riding, eating and sleeping.

In the next post I'll touch on some endurance race basics that I've found helpful.

Monday, 22 October 2018

Munga - Crunching the Numbers

I've done the Munga 3 times. Each time I finished faster:

2015 85h30

2016 73h10

2017 67h34

I don't have the data for 2016 so I'll focus on the 2015 and 2017 numbers to show you how I was able to shave off 18 hours. By the way, 2016 was a dog right out of the starting gate. The temperature was in the mid to upper 40's and we battled into a scorching headwind all through that first afternoon. There were many casualties that day with a huge chunk of the field throwing in the towel before the sun rose the next day. Even so, I managed to better my previous time by more than 12 hours. The "how" is interesting. 

Here's the 2015 result. As you can see by my comment the official time was 85h30. 

In 2017 I had it down to 67h34. That's an 18 hour improvement. 

My overall speed for 2015 was 12.63 km/h. Two years later it was 16 km/h. I had targeted 16 km/h before the race so finished per plan. 

So there is the simple secret to improving your time, train to ride faster. 

In my case it works out 27% faster. The raw data looks impressive. However once you drill down the rest of the numbers tell a very different story. Training to ride faster is fine if you come off a low base. I'm a seasoned endurance rider so there is no way I'm going to bang out a 27% improvement. 

While a 27% improvement looks amazing, in practice I had ridden just under 10% faster. A big chunk of that 10% improvement was due to knowing what to expect and riding a lot lighter. 

Let's look at the underlying numbers. 

I remember looking at this data after the race and being very disappointed. My result was fine but these numbers stunned me. I had finished in 9th place in a time of 85h30 but the data showed my moving time as only 59h44. 

I was supposed to be racing yet managed to spend 26 hours off my bike. As I tried to piece together my race I couldn't reconcile the time off the bike with the benefits of being stationary. This was a game changer for me for future endurance races. 

My strategy going forward was to cut out the time when I wasn't doing something beneficial. Beneficial = feeding and sleeping. What else matters? I've seen people resting up for an hour at a race village and that's okay, I guess. For me that doesn't work. 

Picnic legs are a thing, certainly for me. Picnic legs for those of you who don't know is the heaviness you feel in your legs after you've stopped for an extended coffee or breakfast break midway through your weekend ride. The exhilaration you experienced when charging into your coffee/breakfast spot is soon forgotten as you try coax some interest back into your tired legs.   

Did my new strategy yield results? 

We'll see in the next post. 

Sunday, 21 October 2018

What are your time goals for Munga 2018?

Munga, unlike the Freedom Challenge, is a numbers race. It's the sort of event you can plan with the aid of a spreadsheet or simple mathematics. The Freedom Challenge is exactly the race to crush you if you have crunched numbers to figure out your moving time over distance. For example, the last day of the Freedom Challenge Race Across South Africa is only 56km. Tucked in there is a section of 7 km that typically takes 7-9 hours but has entrapped some riders for 32 hours. The varied and difficult terrain over the whole route makes average speed calculations of no practical use. By the way, those last day 56km take anywhere from 9 to 13 hours depending on the weather. It took me 16 hours this year. Partly miserable weather and partly because I was properly hollowed out after 12 days of racing at my limit.

But the numbers methodology can and has worked for the Munga. There are one or two (or perhaps 3 or 4 depending on your fitness and strength) climbs that necessitate a portage but they only take 5 to 15 mins each before you are back on the saddle.

Let's start with a few basics. A weekend ride with your buddies on a road bike will typically involve 1% ascent. That is, if you ride 100 km you will do something in the order of 1000m of total ascent. An off-road MTB trundle with bud's will typically yield 1.5-2% of ascent. Meaning that 50-60km of riding will give you 1000m of ascent. Before you start paging back through Strava to dig out your past stats to prove me wrong understand that these are broad stroke numbers.

The Munga is 1080km long with just under 7500m of ascent. That's a lot less than the 1% of a typical road ride and about 1/3 of the typical ascent for a typical mountain bike race. It's flat and it's fast - calculators at the ready.

Race distance = 1080km
Cutoff time = 120 hours
Overall speed required to make the cutoff?
Yup, your calculator is not malfunctioning - it's 9 km/h
In the next post I'll unpack the data from my previous Munga's and the numbers should give you a good heads up on how to target a reasonable finishing time.