The Inside Run – 2017 vol. 2

Front Runner Sports are pleased to commence a practical, monthly summary of recent research relevant to distance runners. Our expert team will pick their highlights from the previous month to give YOU The Inside Run on how new and practical research can assist you to beat YOUR best. Please see our summary below!

 

  1. Running Surfaces

Has your running coach told you to vary your running training surfaces through the week or has your physio recommend you seek out softer surfaces on your long and easy runs such as grass or trails? The typical reasoning behind these recommendations is all to do with load variation. The repetitive nature and high chronic loads associated with distance running immediately put you at a high risk of overuse injury (particularly when you are increasing your training load towards a new goal). However, varying the way load enters your body is an effective way to reduce this risk by ensuring the same tissues don’t get loaded in the same way all the time. Load variation strategies include concomitant footwear use, completing different training sessions and running over different surfaces. It’s important to note that if you run at the same speed, running on soft surfaces (such as a trail or grass) won’t reduce the amount of load that enters the body (f = ma), but it will vary the way it enters the body due to the less predictable surface response.

A paper released late last year looked into the effect of running at two different speeds over 3 different surfaces (concrete, a running track and a woodchip trail) on vertical acceleration through the tibia (shin bone). As expected, the slower running speed resulted in lower tibial loads (as f = ma, so the slower the running speed, the less acceleration into the ground and therefore less load through the shin). Running on the most varied surface (the woodchip trail) also led to reduced tibial loads. However, as discussed above, this doesn’t mean that the overall load entering the body was less (the same runner’s mass was hitting the ground at the same speed), but simply less load passed through the tibia (i.e. the load was spread and was passed on to other tissues). So whilst load variation is an effective strategy for the majority of runners, runners with past or present shin pain may be of most benefit to incorporating varied surfaces in to their training week.

Read the paper HERE

 

  1. Increasing Cadence – How much?

Increasing your running cadence (how many strides per minute you take) has been shown to be a very effective way to increase your running economy (how much effort it takes to run a particular pace) and reduce joint loads. This is typically a result of landing closer to your COM, having a reduction in vertical oscillation and spending less time absorbing load. However, as with any change in movement, what is the optimal change to make?

This paper looked at the effect of manipulating cadence on plantar pressures and found that 10% changes were effective at altering foot pressure, whilst 5% changes were not. When a runner changed their cadence by 5% relative to their preferred cadence at the same speed, no significant differences in plantar pressures were found in either direction (i.e. a 5% increase in cadence didn’t decrease pressure and a 5% decrease in cadence didn’t increase it). However, a 10% increase in cadence (more steps) led to a significant reduction in plantar pressures in both the rear & mid foot, whilst a 10% decrease in cadence (less steps) resulted in a significant increase in plantar pressure to the rear foot.

Read the paper HERE

 

  1. Lightweight Shoes = Performance

Many of you may have heard the saying that taking 100g of mass off your footwear can improve your running economy by 1%. Roger Kram and his team conducted this well known study and now he is back to see whether this small change in running economy (1% per 100g) is enough to affect running performance (i.e. will wearing lighter shoes actually make you run faster).

They tested running performance over 3000m and compared running performance in a control shoe to the same shoe with added mass of 100, 200 & 300g. Not only did running economy decrease when mass was added (the runners used more energy) but their time trial performance slowed. Interestingly, this decrease in running performance happened in a linear fashion; for every 100g of added mass, time trial performance reduced by 0.78%.

Now before you go out and buy the lightest shoe possible, there are a few important things to understand. In this study, the lighter and heavier shoes had the same amount of cushioning in them, meaning the sole variable that was tested was the shoes’ mass. However, when you buy lighter shoes from your local specialty running store, the lighter shoes will typically have LESS cushioning. So depending on your running goals, the reduced weight of the shoe may be outweighed by the fact that it doesn’t cushion your feet and lower limbs as well, which could end up costing you more energy/time especially as your race distance goes up.

As always with athletic footwear, there is no blanket recommendation for everyone, but this study reinforces the idea that the lighter the shoe (for the same cushioning) the faster you could run. However, this is an exciting prospect for runners. As shoe cushioning technology continues to improve, the same level of cushioning can be provided through lighter materials leading to faster running!

Read the paper HERE

 

  1. Heavy Weight Training Improves Economy

This paper is not a new one, but it was passed onto us recently by a colleague and provides a great summary of previous research investigating how weight training (heavy lifting) affects your running economy. As we saw in the footwear example above, improving your running economy (using less energy for the same intensity) can lead to improved running performance. There are many ways to help improve running economy in runners, however the best way to do this without running itself is to get into the gym and lift heavy weights. This systematic review summarised the relevant articles on this topic and concluded that heavy weight training could improve running economy within a few weeks, but a long-term training program was necessary to see the significantly large gains that are possible – consistency is key!

Read the paper HERE

 

  1. Heat training

The positive effects of altitude training on running performance are well known (training in hypoxic conditions forces the body to increase the oxygen carrying capacity of the blood, improving your aerobic fitness). Through slightly different mechanisms, the effects of heat training have also been shown to improve running performance. Many Perth runners training in the Summer and then racing in a cooler environment may have noted an anecdotal improvement in running performance. This paper investigated whether these positive effects could actually help you prepare for altitude conditions. It was found that heat acclimation could reduce the physiological strain at rest and during moderate-intensity exercise when at altitude. This was achieved via cellular adaptations that improved oxygen delivery to the working muscles from increases in plasma (blood) volume and reductions in body temperature.

When planning your goal race, a race environment that is cooler than your training environment is ideal, but heat training can be an effective way to help prepare to perform optimally in warm or hypoxic conditions.

Read the paper HERE

 

Running Regards,

Team Front Runner