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Gene in focus: Part 29 - TRHR

Posted 427 Days Ago in: Training, Genetics


The next gene in our “Gene in Focus” series to get put under the spotlight is TRHR. This gene encodes for the thyrotropin-releasing hormone receptor, which is a receptor for a hormone called thyrotropic-releasing hormone (TRH), which is released from the hypothalamus. When TRH binds to TRHR, it causes a number of different cellular signals to occur, which in turn stimulate the thyroid gland to produce thyroxin, which in turn plays a role in the growth and development of skeletal muscle. Small changes in the TRHR gene mean that the hormone receptor is not quite as good at binding with TRH, which in turn can reduce or limit the amount of muscle that can be produced following training.

All of this sounds quite complex, which can often be the reality of looking at the effects of genes on certain traits (you should try working in this field!). However, what it means in simple terms is that people with a certain genotype of TRHR will find it easier to gain muscle mass with weight training, and will likely do so to a greater extent, than people with a different TRHR genotype. A genome wide association study published in 2009 showed this quite nicely. By grouping together the findings of three different studies, involving almost 6,500 Caucasian and Chinese subjects, researchers found that those with the GG genotype had, on average, 2.7kgs more lean body mass that subjects with the TT or GT genotypes. This leads us to conclude that those with the G allele are much more responsive to power-based training, because they have a greater ability to build muscle. The different genotypes and training effects can be summarised as so:




Training Modification


Most likely to achieve favourable improvements in lean body mass and muscle growth with strength training programmes.

Strongest bias training towards to power end of the spectrum.


A more moderate form of the GG genotype; a good response to strength training, but not as good as CC

Moderate bias towards power-based training


Least responsive genotype in terms of lean body mass increases following strength training

Follow a mixed approach towards strength training.


In conclusion, the TRHR gene can have an impact on how well you respond to strength training in terms of improvements in lean body mass. As such, TRHR is included in the DNAFit Peak Performance Algorithm, with the G allele carrying a positive weighting with regards to a power bias.


TRHR Training Gene in focus Strength training Workout Excercise Fitness


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