Monday, 18 August 2014

The "Overshoot Phenomenon" (Part 2)

Carrying on from the previous post, both Andersen et al. (2000 & 2005) showed decreases in Type IIX and increases in Type IIA muscle fibres post training compared to baseline. Once these measures were taken, a 3 month detraining period was implemented. Detraining meaning no resistance training was performed and the subjects returned to their normal daily lives (subjects in both studies were sedentary, no previous regular resistance training and no regular exercise within the last year).

So what happens after a detraining period?

The proportion of Type IIX muscle fibres increased past baseline PRE training values while the proportion of Type IIA muscle fibres significantly decreased below PRE training values.  This is known as the “overshoot.” (Type IIX surpassing pre training values).

What about performance post detraining period?

Andersen et al. (2005) used isokinetic, maximal unloaded knee extension and evoked muscle twitch to measure performance.

Isokinetic testing if anyone didn't know what this machine was

Isokinetic muscle strength and power at 30˚ and 240˚ decreased back to pre training levels. However, angular velocity, angular acceleration, total moment of force, and power during the maximal unloaded knee extension all significantly increased past PRE and POST training values. Furthermore, peak twitch rate of force development (RFD) significantly increased post detraining compared to pre and post training.

An interesting point to note is that the subjects produced greater force post detraining at greater velocities compared to both pre and post training. Also, subjects produced more power compared to pre and post training at greater angular velocities. From these data, we could speculate that the overshoot may only relate to high velocity unloaded movements (E.g. punching, sprint cycling). However, I have also heard this method being used in bobsled with the starting push with great success so even some loaded velocity movements may benefit.

Part 3 will add a study looking at the overshoot with more of a performance based view in professional athletes to see whether or not this phenomenon can be seen in a sporting context. 

Sunday, 17 August 2014

The “Overshoot Phenomenon” (Part 1)

There are only a few papers to date showing the “overshoot phenomenon” (Andersen et al. 2000 & 2005) and only one paper done using professional athletes within a season (de Lacey et al. 2014). Explained very simply, an “overshoot” occurs when a taper or detraining from resistance training takes place. Or in other words, time off is taken from resistance (weight) training. Anecdotally I have heard the Great Britain cycling team used this leading into the 2008 Beijing Olympics for the track cycling and cleaned up the gold medals. For now, let’s go into a little more detail.

There are 3 types of pure muscle fibres (to keep it very simple). Type I, Type IIA and Type IIX. Muscle fibres can also posses more than one type, e.g. Type IIA/IIX, but for now, we’ll stick to just 3 fibre types. Type I are your slow twitch fibres contributing more to the endurance aspect of muscle contraction. Type IIA and IIX are your fast twitch fibres and contract much more rapidly than Type I. Type IIX contract approximately twice as fast as Type IIA and about 5-10 times faster than Type I but fatigue very quickly.

As resistance training is undertaken for an extended period of time, (e.g. in Andersen et al. 2000 & 2005 it was 3 months for a total of 38 sessions) an adaptation occurs where the number of Type IIA muscle fibres increase while the number of Type IIX decrease compared to pre training. As shown in Andersen et al. (2000), a significant increase in Type IIA and a significant decrease in Type IIX were found post training. So we have a decrease in the bodies most powerful muscle fibres and an increase in more efficient fast twitch fibres.

So how do we increase Type IIX muscle fibres and potentially muscular power? Could this be useful for your sport you compete in? These will be explained in upcoming parts!


Sunday, 10 August 2014

Contrast Training to Develop Horizontal Capabilities

As promised, here are a few examples of complexes to develop horizontal capabilities.

A1. Hip Thrust 3-5x5-10             
A2. Broad Jump 3-5x1-4

A1. Heavy Sled Push or Drag 3-5x10-40m
A2. 10m Sprint 3-5x1

A1. Heavy 45˚ Back Extension 3-5x5-12
A2. Med Ball Scoop Toss 3-5x1-5

A1. Kettlebell Swing 3-5x5-10
A2. Light Sled Sprint 3-5x10-40m

A1. Glute Bridge 3-5x5-10
A2. Bounding 3-5x10-20m

These are just some examples of pairing a force based exercise with a velocity based exercise to help improve power output in the horizontal direction. Doing the complexes in this order enhances the explosive capability of the muscle, otherwise known as post activation potentiation. You can get creative with these and pair all sorts together.