It’s now May, and almost four months since I had foot surgery to sort out my Morton’s neuroma. So far, so good: the healing is going well, and thankfully, I’m running again – albeit just 10km, three times a week.
Don’t overdo it, the surgeon told me.
How will I know? I asked.
Your foot will tell you, was the reply.
How will I know? I asked.
Your foot will tell you, was the reply.
And tell me it does. Still now, 16 weeks on, if I overstep the mark by trying to push distance, or if I try to hammer a technical descent, it protests loudly. It detests jarring or pounding, and sends out a neural “twerk” from foot to brain like a blot of lightning if I stomp my foot hard on the ground. So, tread gently I do… with ever-enduring patience.
Inevitably my fitness has suffered from 8 months of radically reduced cardio, but it’s my lungs that seem to protest the loudest. Alas, the only way around that will be by hard grind work – the high intensity stuff that I love the least!

The Grucox Studio in the High Performance Centre at SSISA
Thankfully, throughout my recovery I’ve been able to maintain my leg strength – and, ironically, even improve it. This was not, however, through my own doing – instead I handed myself over to the expertise of the Sports Science Institute of South Africa (SSISA) and was Grucoxed! As it so happened, just two weeks after my operation in mid January, SSISA was starting a Grucox training course as a strengthening programme for runners preparing for the Old Mutual Two Oceans Marathon. The 10-week programme was designed to build-up, strengthen and taper runners preparing for the 56km and the 21km. Of course I wasn’t running Oceans, but being desperate for all the help I could get, I signed up anyway, and put myself into the capable hands of SSISA. And it turns out to have been the best thing I could’ve done for my rehab!
Twice a week for 10 weeks, the one-hour session had us doing 20 mins of mobility and strength exercises, followed by 20 mins on the Grucox bikes, then 20 mins of stretching. A fully supervised muscle makeover in 10 weeks!
What on earth is this “Grucox”?
The first thing I learned about Grucox is that it’s all about eccentricity.
Not eccentricity as in weird behaviour, or doing stuff that’s considered out of the norm… although clearly peddling backwards at max output on a stationary bicycle may well be regarded by most as being rather strange… But eccentricity as in eccentric (pronounced eee-sen-trik) exercise, the scientific term given to how muscles behave when you lengthen them, as opposed to concentric exercise, when you shorten them.
For example, when you lift a weight, your bicep undergoes a concentric contraction – it shortens. When you slowly release that weight and straighten your arm, your bicep lengthens and go through an eccentric contraction. It does this because of an opposing force that’s greater than the muscle generates.
Not eccentricity as in weird behaviour, or doing stuff that’s considered out of the norm… although clearly peddling backwards at max output on a stationary bicycle may well be regarded by most as being rather strange… But eccentricity as in eccentric (pronounced eee-sen-trik) exercise, the scientific term given to how muscles behave when you lengthen them, as opposed to concentric exercise, when you shorten them.
For example, when you lift a weight, your bicep undergoes a concentric contraction – it shortens. When you slowly release that weight and straighten your arm, your bicep lengthens and go through an eccentric contraction. It does this because of an opposing force that’s greater than the muscle generates.
The Grucox machine is a stationary bike that has motorised pedals. In a nutshell, you sit on the bike and resist the forward / backward motion of the pedals. Each session is 20 mins, and then you’re done. Simple.
Simple it may appear, yes. And you’re likely to leave that first session wondering what all the fuss is about. But the following day, I learned why the Grucox bike is effective… it works muscles that otherwise take it easy! My glutes, my hammies, and even my lats and shoulders had been worked without me even realising. We all know having strong glutes improves our running. Activating and strengthening our glutes is essential. If our glutes are weak, the stronger muscles of the quads and hamstrings have to work harder, which puts greater strain on them than necessary.
What’s so great about eccentric training?
By trying to resist or slow down an opposing force, your lengthening muscle provides a controlling force to the joint movement. Doing this repeatedly, and in controlled conditions, strengthens those muscles.
Working out on the Grucox machine (eccentric exercise) enables greater strength gains than conventional resistance training (concentric exercise) – it improves muscle strength and encourages better muscle control, thereby helping to prevent injury; and all this with low impact on the joints. That’s a pretty good deal for anyone wanting to strengthen and tone their leg muscles, improve strength and performance, or, as in my case, rehab after injury or surgery.
Grucox isn’t just for runners either – loads of cyclists love it too.
And the weird name: Grucox?
The Grucox machine was developed by Cape Town based orthopaedic surgeon Dr Willem van der Merwe, who was schooled at Greys College (GR..), and studied at UCT (..UC..) and Oxford (…OX). Pretty nifty acronym, right?
My 10-week post op muscle makeover certainly helped my rehab – it enabled me to maintain the condition of my leg muscles while I wasn’t able to run, and to strengthen specific muscles – particularly my glutes – to enhance overall power. What’s not to love about that!
And the last point to rave about is that SSISA is offering a number of these structured 10-week Grucox programmes throughout the year – there’s one running currently as a Comrades build-up, and the next one starts in June (18 June til late August. For more info or to secure a spot on that course, email Ayden Smith on asmith@ssisa.com .

Our group for the Grucox 10-week programme in Feb/March
Thanks for sharing, I’ve emailed Ayden at SSISA – Im seriously very int in this as part of a rehab protocol to gain strength after suffering from a hi-hamstring tendon (recurring/chronic) injury. I’m a triathlete &trail-runner, busy recovering from this nasty (painful) injury post-Full IronmanSA.