The way our body reacts to force is fascinating. Run on soft sand and run on bitumen and you’d think they were virtually the same; it’s all running, right? However, any of you that have tried the two will know how much more exhausting it is to run on soft sand when compared to a hard surface like a road. So, with primarily the same movement, (and there are hundreds of examples) the way your body reacts is very different. Why is that?

The start of a new understanding

I used to think it was just an intensity thing. It’s just ‘harder.’ However, my soft sand runs were 40% slower than my road runs, but my heart rate was the same or higher, so that put pay to that argument. The answer was not complicated, but it was eye-opening. My soft sand runs were far more contractile, and my road runs far more tensile. Let’s get a handle on what these two words mean.

Contractile training

  • More muscular
  • Less stretch reflex
  • Energy expensive
  • Often more isolated
  • All about the generation and absorption of force
  • Short training periods (weeks) can create improvements in tissues quickly

Tensile training

  • More fascial
  • Considerable ability for stretch reflex, but can also be stiffly reactive
  • Energy efficient
  • Integrated across the body
  • All about mitigation and elastic release of force
  • Requires long training periods (6 months to years) to create improvements in tissues

So, what do you train, and for whom?

Hopefully, when you read through this list, some bells might start ringing. Look at the graphic below. Would you train all these people with traditional weight training, which is almost entirely contractile? It’s just a question, not an accusation, so please take this on board and consider the variables of each athlete.










The surf lifesaver and the marathon runner – do they need the same weight training program? Do you need to look beyond the weights for either? The AFL players and the beach volleyball athletes – do they need simply weight training in their programs? The building worker digging and the golfer; how about their program? Is it all weight training, for everyone?

The tensile athlete

At this point, it’s worth showing you a tensile athlete doing tensile training as it will bring home the difference between this and all the contractile training we’re used to seeing and doing in the gym. This is Stefan Holm, an Olympic high jump gold medallist, despite being below 6ft.







Can you see how effortless it is for him to hurdle barriers placed at head height? And yet muscularly he is relatively light and lean. An interesting little fact about Holm is that his Achilles tendon was measured as four times stronger than the average male. He didn’t create this ability solely from weight training. He had to train beyond his contractile skills…he trained his tensile system. This effectively means he trained the elasticity you find in the connective tissues of the body; our most ubiquitous protein, wrapped around every muscle fibre, fascicle, muscle, nerve, bone and organ in our body.










Elasticity and where you find it

A little clarification on what muscles and connective tissues do is worth discussion here. In recent times, it’s been debated whether muscles really do lengthen and shorten, or do they simply act isometrically, with the surrounding connective tissues doing the lengthening and shortening. For some interesting new light on this topic, in vivo research is needed, to discover what happens in real life when we’re moving in the presence of force (i.e. all the time). There are a couple of Japanese studies which prove very enlightening.

Using ultrasonography in 2006 in the medial gastrocnemius, they found that during human gait:

“The mechanical energy provided by the pre-stretched tendinous tissues reached [up to] 85% of the total energy; thus, the vast majority of power enhancement is provided by muscle-tendon interactions.”

This alludes to the idea above that muscles perform predominantly isometricallyin moderate intensity work. But what about higher forces? In 2008 the work was furthered using drop jumps to give a greater understanding of increased forces. Here they found:

“tendons can still be stretched rapidly and can reach high forces (Achilles tendon force: 10-12 times body weight) in early braking” and further:

“A reduction of fascicle work with a concomitant increase in the storage and release of elastic energy in the tendons can explain how an increased impact load affects the efficiency of the push-off phase of SSC (stretch-shorten cycle) exercises.”








What does it all mean?

Thanks for sticking with this so far. Here’s where I hope it starts to make sense. If we’re conditioning someone for road running, a hiking holiday, hard court tennis, netball, squash, jumps, basketball and all other hard surface sports then weight training is still essential. It’s equally important to complete some training of the tensile(fascial) system. How might we do this? Well:

  • Movement training that harnesses gravity and ground reaction force
  • The whole body integrated movements
  • Multi-directional, reactive movements
  • Loaded movement training with tools like ViPR, Sandbell, cables

Examples from my own studio for this type of training would be multi-directional bounding, old school hopscotch, single leg balance while playing catch from multiple vectors, low hurdles and all similar RAQS type training. This is in addition to the whole body elastic loaded movement training with ViPRs and Sandbells.










How do we know how much of each people need?

This question has no definitive answer. If I ask you how much tensile training a hard court basketball player needs compared to a beach volleyball player, without an in vivo study to back me up, I can’t give you a specific percentage of each. However, as a fitness professional, I think you can already tell me that the basketball player needs more tensile training than the athletes on soft sand.

Similarly, the roadrunner needs considerable help with tensile strength than most are currently getting. When I was running marathons, my gym program was full of squats, lunges, and deadlifts. Well, I’m grateful for all that contractile work now I run on soft sand, but I have far more understanding of my numerous injuries from marathon training now than I did then. My program prepared me for contractile work when it was almost entirely a tensile sport. My tensile system broke down all the time.

The parting message

So what’s the message here? Get to know your clients’ goals and then consider what this means knowing what we’ve discussed above. Does everyone need to be doing all the contractile style strength training that we’re putting people through in gyms? It doesn’t mean we’re doing it wrong; it just means maybe the balance is off and we can reconsider what percentage of contractile work and what percentage of tensile work we need to be doing. Determine that percentage by understanding your client’s needs and making your own judgment call. Yep, I said it – a judgment call. Science can’t help us here. We need to rely on our knowledge and then add our instincts. I think you’ll find you’re much closer to what your clients now need than many gym programs out there. Good luck!


Kawakami, Yasuo; Fukunaga, Tetsuo. New Insights into In Vivo Human Skeletal Muscle Function

Exercise & Sport Sciences Reviews: January 2006 – Volume 34 – Issue 1 – pp 16-21

Ishikawa M1Komi PV. Exerc Sport Sci Rev. Muscle fascicle and tendon behaviour during human locomotion revisited.2008 Oct;36(4):193-9. doi: 10.1097/JES.0b013e3181878417.

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