While there is much debate & interesting research around pacing strategies there is little doubt over the need for them in endurance events. In this post we'll be telling a cautionary tale about Athlete X (names have been changed for the fun of it). X hadn't run a marathon for 3 years & was intent on running a near personal best (PB) in her return at Cape Peninsula Marathon 2020. We will look at the 2 planned assessment runs (shorter test races) a 21 km & a 30 km as well as the marathon itself in order to show how pacing played a significant role in each.

Landmarks 21.1 km 2019-11-03

Landmarks Half has an infamous 'hill', Rhodes Memorial as the prominent feature of its profile. Conveniently the summit is just about half way through the race & the climb & decent dominate the middle portion of the race.

fig 01: Landmarks 21.1 km - Course Profile

The profile is dominated by Rhodes Memorial.

The nature of this course lends itself to a 'pacing table' strategy where an average pace is maintained for a particular distance or from landmark to landmark. Planning in segments allows the athlete some leeway over the chunk. We split the race into 3 x 5 km + 1 x 6.1 km 'quarters' & set an average pace for each lap.

The 2nd 5 km lap is the most challenging & therefore the focus of the planning. After calculating the average slope over the 4 km climb as...

slope = elevation ( acme ) - elevation ( nadir ) distance ( acme ) - distance ( nadir )

we looked at her recent runs up similar slopes. Fortunately there are plenty in our neighbourhood & we took an average of her pace over these & reduced that to account for the intensity of the race. The same calculation was applied to the downhill. The flat 1st & last laps where used to balance target pace.

table 01: Athlete X: Landmark 2019 - Pacing Plan

lap end (km) lap pace lap time total time avg. pace
5 6:00 30:00 30:00 6:00
10 7:20 36:40 1:06:40 6:40
15 5:45 28:45 1:35:25 6:22
21.1 6:00 30:00 2:12:01 6:15

The target pace for this particular point in the build up to the marathon was relatively leisurely 6:15.

Targeted training & recovery completed (more on this in an upcoming post), she was ready for the race. The race seemed to have gone well with a finish time of 2:13, very close to the targeted 2:12.

fig 02: Athlete X: Landmarks 2019 - Pacing Profile

The pacing profile is superimposed on the course profile for comparison.

Plotting the

relative pace ( % ) = rp ( % ) = ( mrp - pace ( lap ) mrp ) 100


mrp = mean race pace = time ( total ) distance ( total )

allows us to see where time was 'made' or lost during the run. Adding the profile allows us to see how the terrain affected the run.

The 1st sign that something wasn't quite right is the falling pace in the downhill in the 10 - 15 km section. Slowing on a downhill, especially after the acceleration over the summit implies X was suffering from early fatigue. One might be tempted to say she 'hit the wall', but since the wall is only technically defined for marathon+ distances...

Since there was a fixed pacing plan in place we can compare the planned & achieved.

fig 03: Athlete X: Landmark 2019 - Pacing Debrief

Seems the 2nd lap, the uphill was run too fast.

She ran the hill much faster than planned & the effect is seen in the final segment of the race. In this case the early enthusiasm & the later fatigue cancelled each other out almost perfectly.

Bay to Bay 30 km 2020-01-19

Fish Hoek / Tokai 30 km 2020-01-19

Bay to Bay is another race that, due to it's extreme profile lends itself to a fixed pacing plan. However since the race was cancelled on the line due to the weather conditions it was never implemented. Races are seldom cancelled due to weather but having driven the course to the start I have to agree with the organizers decision.

After driving back to the relative shelter of the South Peninsula, we had breakfast. X, who again was well trained & recovered was intent on the 30 km preparation run that had been planned. She ran, joining bits of known routes from Fish Hoek through Tokai & back. Since there was no plan in place the strategy was to run maintaining a relatively steady power output (approximated by heart rate). Effectively the terrain would set the pace.

fig 04: Athlete X: 30 km Personal Best - Pacing Profile

Note the scale for the elevation. The run was not mountainous as the profile might suggest but hilly.

Very well paced, hence the PB. Other than the bathroom break at around 21 km, the pace stays within a narrow range around the mean pace. The dip in pace over the last hill is partially fatigue & partially due to it being congested.

Cape Peninsula Marathon 2020-02-16

The Peninsula Marathon has a reputation for being fast (unless of course the wind is blowing). That & being later in the season makes it a good run to get a good seeding in the upcoming ultras. It is also scenic.

Once again X was well prepared. Following her success with managing her pace based on heart rate & her familiarity with the race, we decided to follow the same strategy.

fig 05: Athlete X: Peninsula 2020 - Pacing Profile

The major climb is ~20 m / km for 3 km.

X crossed the line 20 minutes after her target time, swearing about the f***ing thorns that literally covered the entire sports field where the race ended & utterly confounded as to why the last 12 km had been so dreadful. Yes she did all this barefoot (more on that in another post).

mec: Why did you suddenly accelerate half way up a serious climb.
X: ...
mec: Was he cute?
X: <blushing> He said "Just when I thought I was hardcore..."

In this instance we can definitely say that Lyndall... um I mean X, hit the wall. In fact this is the very definition of WALL, valiant attempt to scale it & all. No matter how we choose to pace ourselves the message remains clear:

Early exuberance will lead to pain later.

- mec