Monthly Archives: January 2016

How exposure to blue light affects your brain and body

 

I know this. You know this. Most people still act like it doesn’t matter. Most people are stupid.

Light-exposure can be good or bad depending on when it occurs. As mentioned in the post “electronic devices before sleep?” which highlights the results from Chang et al. 2014,  your nighttime Ipad/kindle-reading will have adverse effects on your sleep and health.

 

The infographic below sums it up pretty nicely: If you exposure yourself to (blue) light before bedtime, you´re going to have a bad time!

 

ti_graphics_how-blue-light-affects-body-(1)

Importance of mind-muscle connection during progressive resistance training

… is the head-turning title of yet another really nice article in a series that seems never-ending. – I am sure Jimmy agrees.

Basically, the study by Calatayud et al. 2015 sought to evaluate wether focusing on specific muscles during the bench press exercise can selectively activate these. As the abstract below shows, the results are quite interesting.

In short, it seems that focusing on a specific muscle will increase the activity of this muscle, without decreasing the activity of other prime-movers. In contrast, when specifically focusing on the triceps muscle during benchpress and hereby increasing the activity, the activity of the pectoralis muscles were also increased at loads corresponding to 50% and 60% of 1RM.

Note that this effect seems to “wear off” when playing around with higher loads (80% of 1RM), so it´s something that could, and should, be used for your training sessions focusing on power.

 

METHODS:

Altogether 18 resistance-trained men participated. Subjects were familiarized with the procedure and performed one-maximum repetition (1RM) test during the first session. In the second session, 3 different bench press conditions were performed with intensities of 20, 40, 50, 60 and 80 % of the pre-determined 1RM: regular bench press, and bench press focusing on selectively using the pectoralis major and triceps brachii, respectively. Surface electromyography (EMG) signals were recorded for the triceps brachii and pectoralis major muscles. Subsequently, peak EMG of the filtered signals were normalized to maximum maximorum EMG of each muscle.

RESULTS:

In both muscles, focusing on using the respective muscles increased muscle activity at relative loads between 20 and 60 %, but not at 80 % of 1RM. Overall, a threshold between 60 and 80 % rather than a linear decrease in selective activation with increasing intensity appeared to exist. The increased activity did not occur at the expense of decreased activity of the other muscle, e.g. when focusing on activating the triceps muscle the activity of the pectoralis muscle did not decrease. On the contrary, focusing on using the triceps muscle also increased pectoralis EMG at 50 and 60 % of 1RM.

CONCLUSION:

Resistance-trained individuals can increase triceps brachii or pectarilis major muscle activity during the bench press when focusing on using the specific muscle at intensities up to 60 % of 1RM. A threshold between 60 and 80 % appeared to exist.