謝教練科普。看看自己的基因，就知道是不是擅長耐力運動了。

from 23andme:

Genetics and Muscle Composition

What's in a muscle?

Our muscles are made up of two main types of fibers, called slow-twitch and fast-twitch. Fast-twitch fibers allow rapid, forceful muscle contraction — the sort of contraction required for sprinting. Slow-twitch fibers contract more slowly, but they also tire less easily. Endurance athletes tend to have more slow-twitch fibers, while power athletes (including sprinters, throwers, and jumpers) tend to have more fast-twitch fibers — a difference that may reflect both their genetics and their training habits.

Muscles and genetics

This report is based on a genetic marker in the ACTN3 gene. This marker controls whether muscle cells produce a protein (called alpha-actinin-3) that's found in fast-twitch muscle fibers. While some people don't produce this protein at all, almost all of the elite power athletes who have been studied have a genetic variant that allows them to produce the protein. This suggests that the protein may be beneficial at least at the highest levels of power-based athletic competition.
 

	Genetic result
You	CC Common result for elite power athletes
	CT Common result for elite power athletes
	TT Uncommon result for elite power athletes

 

Genetic result	European	African	East Asian	Latino	South Asian
CC Common result for elite power athletes	31.2%	61.5%	30.2%	24.0%	15.8%
CT Common result for elite power athletes	49.3%	33.7%	49.3%	49.0%	47.6%
TT Uncommon result for elite power athletes	19.4%	4.8%	20.5%	27.0%	36.6%

CC

Common result for elite power athletes

European	African	East Asian	Latino	South Asian
31.2%	61.5%	30.2%	24.0%	15.8%

CT

Common result for elite power athletes

European	African	East Asian	Latino	South Asian
49.3%	33.7%	49.3%	49.0%	47.6%

TT

Uncommon result for elite power athletes

European	African	East Asian	Latino	South Asian
19.4%	4.8%	20.5%	27.0%	36.6%

About endurance athletes

Most of the elite power athletes who have been studied have a genetic variant that allows them to produce the alpha-actinin-3 protein in their muscles. Does that mean that people who don't produce this protein are more likely to be endurance athletes? Studies in mice suggest that the answer may be yes: young mice who don't make any of this protein are able to run farther without getting tired. But studies in humans have not consistently shown an endurance advantage for people who don't produce the alpha-actinin-3 protein.

Genetics isn't everything

Differences in the genetic marker used in this report may only explain about 2-3% of the difference in muscle performance between different people. In elite athletes who work intensely to reach the upper limits of their potential, that 2-3% may mean the difference between qualifying for the Olympics and missing the cut. But for the rest of us, the choices we make about how to train will far outweigh the contribution of our genetic result at this marker.