ACTN3 gene full deficiency, anyone?

[Zuman]

After signing up for the 23andMe genetic analysis program, I learned that I'm "fully deficient" in the so-called "sprinter's gene." As someone with the TT variant of the ACTN3 gene - like 19.4% of those with European ancestry - I don't have the genetics commonly found in elite power athletes. While we may have a bit of an advantage in endurance activities, those without the sprinter's gene don't develop big muscles and are 2.6 times more likely to suffer an injury than athletes with the variant (and those injuries are more likely to be of greater severity).
That makes sense to me. I'm now nearly 69, and have a relatively slight build for a male at 5'9" tall (used to be 5'10") and 157lb. I played rugby, ran track, and cycled, and it seemed that I always had to work twice as hard as others to remain competitive. And I DO have a competitive nature! I lifted weights for 45 years, but never really built any mass, and I seemed to injure myself at least once a year doing so (my testosterone levels were - and still are - good).
I've been rowing now for three years, mostly indoors but also some on-water. I've had a few minor muscle injuries, but nothing serious, and I really enjoy it.
Here's my issue: my genetic profile tilts toward endurance rather than power, but training for endurance events is tough because it seems like there's no substitute for simply piling on the meters by the hundreds of thousands, and I already do about 2 million meters/year on my C2 erg. Apparently, interval training is not very effective for ACTN3-TT individuals.
I'm sure that there are others here who share the ACTN3-TT profile. Have any of you found any training approaches that have been especially effective? Thanks!

[Cyclist2]

Never had a genetic analysis done, but like you I tend more toward endurance than sprinting. However, every race I've ever been in (running, cycling, rowing - and I'm 70 so like you there have been a lot) I've wished I'd done more intervals. I seemed to get dropped just when I needed to have that little bit more power, which comes from interval training.

You can incorporate intervals in a way that will minimize injury (try the Pete Plan for example), and even with the "inadequate" sprinting genetics you will get faster (or at least not fade) when the going gets hard. Rowing is an endurance sport, but believe me; in the last 500 meters of a 2K or even 5K effort, you'll be wishing you'd done more intervals.

[Dutch]

I assume you are the X/X genotype: which means endurance advantage. Here is a link to a study done for just this type of situation you find yourself in: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4624116/

It should at least offer you an insight to your situation and you will be able to conduct more research from there. Particularly look at table one as you scroll down, it should tell you all you need to know at a quick glance if all the rest is rolling over you.
Also follow some of the numbers in the right hand column of table one, they are references to other studies they may give further insight. Some will be brief some will be informative. Only read one at a time and come back to the table or you may well lose your self in too many facts.
I often end up with multiple pages open when I access a peer reviewed study and forget what I read where.

[igoeja]

I am reading The Sports Gene by David Epstein, and one of the chapters focuses on ACTN3. On 23AndMe, from a test I took years ago. I have "genetic muscle composition is common in elite power athletes." At the time, I assumed that it was bad for my primary activities, endurance sports, particularly rowing, but on further investigation, I found the science behind this mixed, with some studies indicating a higher RR or RX typing in elite rowers, or alternatively, different typing dependent on size and gender. From what I read it is not clear cut.

Studies:

- ACTN3 R577X polymorphism in top-level Polish rowers: https://www.sciencedirect.com/science/a ... 9X12000056
- ACE and ACTN3 Gene Polymorphisms and Genetic Traits of Rowing Athletes in the Northern Han Chinese Population: https://pubmed.ncbi.nlm.nih.gov/34721527/
- Influence of ACTN3 R/X gene polymorphisms on racing strategy in rowing athletes: https://www.tandfonline.com/doi/abs/10. ... 17.1416527

Other:

- 23AndMe: https://you.23andme.com/reports/wellnes ... mposition/
- The Sports Gene by David Epstein (GoodReads): https://www.goodreads.com/book/show/186 ... ports-gene
- The Sports Gene by David Epstein (Amazon): https://www.amazon.com/gp/product/B00AE ... ide_sin-20

[igoeja]

I did a little bit more searching...

- The ACTN3 R577X polymorphism in Russian endurance athletes: https://bjsm.bmj.com/content/44/9/649

- World-class performance in lightweight rowing: is it genetically influenced? A comparison with cyclists, runners and non-athletes: https://pubmed.ncbi.nlm.nih.gov/18801770/

- Does the polygenic profile determine the potential for becoming a world-class athlete? Insights from the sport of rowing: https://pubmed.ncbi.nlm.nih.gov/19422651/