The IM run is probably the most daunting of the three legs (no pun intended) and is certainly the harshest on the body. The ability to run in a highly fatigued state for so long is no easy task even in optimal conditions. The technical challenge is to hold form throughout to sustain your goal race pace – holding TUF (technique under fatigue) as we say at Trisutto. As mentioned in my previous blog, success on the run is very much predicated on your bike fitness, pacing and fueling management. A proper triathlon-analysis of any run performance should take the bike segment into consideration. For this discussion I will assume the stage set with a well-delivered bike.
What is 'proper' IM running form?
The crux, like the swim, is in the ability to cover the race distance at (your) speed “comfortably”. It starts with your form, one that you can replicate sustainably for ~40000 steps over 42k. There is no right or wrong, only what is effective for you, based on you(size, weight, shape, anatomical anomalies etc.).
Attempting to emulate track runners or shorter distance runners is misguided, especially if you are a late starter in the sport. Very few, even at the highest level of our sport, are capable of running the IM like a gazelle from start to finish (i.e. Craig Alexander, Andreas Raelert, Mirinda Carfrae). Most end up moving in a manner that is most economical to them. So take heart that you too can still be a good IM runner without conforming to a stereotype “proper form” derived from open events, especially those track specific.
The foot plant is probably one of the most discussed aspects of “proper form”. Whether it is to avoid breaking, to harness the potential elastic energy in our tendons and muscles or to minimize contact time, the mid/fore foot strike (over heel strike) is the mainstream technical goal you are encouraged to achieve. As we watch the best at IM what do we actually find? – A mix of foot contact types – forefoot, mid-foot/flat/outside, and heel “touchers”. Of the top 10 men in Kona 2016 approximately half heel touched, the other half used a flat/mid foot (and one distinct forefoot) plants. Some of top 10 ladies at Kona 2016 also distinctly heel touched. So if you currently favour a heel first contact and are comfortable doing so you may not need to change it. It is essential however to clearly understand the distinction between heel striking and heel touching before tinkering with what might already be a suitable IM form for you. Heel striking occurs when you land on your heel and at full stance your heel is still in front of your center of mass, leg is relatively straight, and weight is being transferred through the heel, which effectively jars the body and causes a breaking action.
Heel touching occurs when your heel contacts the ground first in front of you, briefly, but at full stance your center of mass is close to or over top your weight bearing foot, the leg is bent, head-shoulder-hips stacked with weight being transferred through the supporting mid-foot. From initial contact to full stance the hip continues to translate forward.
Daniela Ryf
If you mid/flat foot strike you will tend to land very close to your centre of mass already (or as close “underneath”) and the time to full stance is almost seamless. If this is you, that is ok.
Mary Beth Ellis
Note in the examples above the similarity in alignment at full stance (right photos) despite slightly different start points.
Both of the highlighted styles are effective. Avoid choosing one over the other to conform to what is deemed “proper” or ideal. The one that still holds by the end of the IM will be the fastest for you.
Start by optimizing what already works for you. If you push to change to be something you are not you could increase injury potential or regress in performance. If, for example, you insist on a mid-foot strike in your IM preparation long runs, now after years of heel touching, you will increase the likelihood of a metatarsal stress fracture. On the other hand, to force a heel touch approach if you are a natural mid-footer will likely cause you to heel strike to make that change felt.
Does this mean you should simply settle and never adjust anything that may improve your economy and speed? Of course not. Small tweaks (rhythmical shoulder extension, compact hand/forearm swing, a more upright and stacked posture, head inclination, cadence etc.) can collectively compliment what happens from the waist down. Just avoid drastically reorganizing your mobile base of support to something that isn’t natural for you. And note that what is natural to you will also evolve as your experience progresses. So how do you make your individual functional technique better? Run. Forget about drills. The more time you spend on them the better you will be at them, but likely no better in form at 35k in the IM run. If your form crumbles forcing you to walk, shuffle and hobble mid-way, all the prancing, skipping, machinegun butt-kicks and explosive knee drive drills you did will have only served to improve your photo pose coming out of T2. Rather focus your technical effort on building race pace (RP) form stamina. Insert segments of IM RP tempo on your long runs. Run off the bike often and following long race-paced efforts to impose the specific (or close to) fatigue that will help forge your IM run form durability. Next time someone comments on your “heel strike”, assess the accuracy of that observation using video and the cues aforementioned before altering anything. Then take heart that many of the best IM runners (and champions) – male and female – contact the ground first with their heel.