Q1. What is the passage mainly about?

1. AHow to win a race
2. BHow to stretch before exercise
3. CWhy muscles grow
4. DHow to sleep after sports

運動前のストレッチのやり方と、その影響についての文章なので B。

Q2. For how long can you stretch each muscle with only a small effect?

1. ALess than 60 seconds
2. BMore than 5 minutes
3. CAbout 10 minutes
4. DOne hour

if you stretch each muscle for less than 60 seconds, the effect is very small とあるので A。

Q3. In this passage, "weaker" means ...

1. Ataller
2. Bfaster
3. Cless strong
4. Dmore tired of studying

weak（弱い）の比較級で「より弱い」＝力が少し落ちる、なので C。

Q1. What is the main idea of the passage?

1. AStatic stretching should never be done.
2. BStretching always prevents injuries.
3. CLong static stretches may reduce power, but short ones have little effect.
4. DTendons do not work like springs.

長い静的ストレッチはパワーを下げうるが、60秒未満なら影響はほとんどない、という内容なので C。

Q2. According to the 2016 review, what makes the effect even smaller?

1. AStretching for longer
2. BDoing a dynamic warm-up afterward
3. CTaking a bath before sports
4. DSkipping the warm-up

the effect becomes even smaller when a dynamic warm-up follows とあるので B。

Q3. When would a long, slow stretch be most suitable?

1. AAfter finishing exercise
2. BRight before a sprint race
3. CJust before a high jump
4. DDuring a game

最終文 Long, slow stretches are better after exercise or a bath. から A。

Q1. What did the 2012 review find?

1. AStretches under 60 seconds per muscle had little negative effect.
2. BAll static stretching greatly reduces strength.
3. CDynamic stretching reduces power more than static stretching.
4. DStretching has no effect on flexibility.

Static stretches of less than 60 seconds per muscle had little negative effect on maximal strength とあるので A。

Q2. Why might many of these experiments exaggerate the effect of static stretching?

1. ABecause they used only gymnasts
2. BBecause they lasted several years
3. CBecause they measured performance right after stretching, not after a full warm-up
4. DBecause they did not measure strength

Many of these experiments measured performance immediately after stretching, which may exaggerate the effect とあるので C。研究方法の限界の指摘。

Q3. Which advice would the author most likely give?

1. AHold each stretch for five minutes before sprinting.
2. BSkip warming up entirely.
3. COnly stretch after an injury.
4. DRaise body temperature, move dynamically, and keep static stretches short.

最終文 A sensible warm-up raises body temperature, includes dynamic movement, and keeps any static stretching brief から D。