영어 모의고사 (자동 편성)

After an especially demanding training session, the instinct to collapse onto a couch and remain motionless is understandable, yet exercise physiologists increasingly ①recommend the opposite approach. Active recovery involves ②to perform low-intensity movement, such as a light jog, an easy swim, or a gentle bike ride, on days following intense exertion rather than resting completely. This gentle activity keeps blood circulating through tired muscles, which ③appears to help clear metabolic byproducts that accumulate during hard exercise more efficiently than complete stillness does. Some athletes worry that any movement at all will interfere with the repair process, but research suggests that truly light activity ④does not meaningfully slow healing and may even reduce the perceived soreness that follows a hard session. The key distinction lies entirely in intensity: active recovery is not a second workout in disguise but a deliberately gentle session ⑤designed to support, rather than compete with, the body's underlying repair mechanisms.

Smartphones, tablets, and computer screens all emit a significant amount of blue light, a short-wavelength light that our eyes are especially ①sensitive to. During the day, exposure to blue light from the sun helps keep us alert and mentally sharp, which is generally beneficial. At night, however, the same wavelength can interfere with the body's natural preparation for sleep. Specialized cells in the retina ②detect blue light and send signals to the brain's internal clock, ③suppressing the release of melatonin, the hormone that signals it is time to rest. Studies have found that ④people who scroll through their phones in bed before sleeping take longer to fall asleep and experience lighter, more easily disrupted sleep than those who avoid screens. Some devices now offer a night mode that shifts the display toward warmer tones, reducing blue light output in the evening. While this feature may help slightly, sleep researchers generally recommend ⑤limit screen use altogether in the hour before bedtime for the best results.

Skipping a proper warm-up before intense exercise might seem like a harmless way to save a few minutes, but the practice carries real physiological costs. A cold muscle is ①more flexible and less elastic than a warm one, making it considerably more prone to strains and tears when suddenly asked to contract forcefully. Gradually raising body temperature through light activity ②increases blood flow to the muscles, allowing oxygen to reach tissue more efficiently and enabling nerve signals to travel faster between the brain and the muscle fibers. A proper warm-up also raises heart rate gradually, ③easing the cardiovascular system into strenuous work rather than shocking it with a sudden demand. Athletes who warm up thoroughly tend to report ④better performance in the early minutes of competition, since their bodies are already ⑤primed rather than adjusting on the fly.

Anyone who has ridden a bicycle after a decade away from one has likely experienced muscle memory firsthand: the body seems to ①recall a complex skill almost instantly, even when conscious memory of the exact movements has faded. Contrary to what the name suggests, muscles themselves do not actually store memories; the phenomenon originates in the brain and nervous system, where repeated practice gradually ②hides control of a well-learned movement from regions associated with conscious thought to areas that operate largely automatically. This shift explains why a skilled athlete can execute a complicated sequence of movements without consciously thinking through each individual step, ③freeing mental attention for strategy and decision-making instead. Interestingly, research also suggests that these neural pathways can remain ④partially intact even after long periods without practice, which is why relearning a skill is typically much faster than learning it for the very first time. Coaches often exploit this principle by ensuring that fundamental techniques are practiced correctly from the very ⑤beginning.

Sleep hygiene refers to a set of simple daily habits that help the body prepare for consistent, ①restorative rest. Experts commonly recommend going to bed and waking up at the same time every day, even on weekends, because an irregular schedule ②clarifies the body's internal clock and makes it harder to fall asleep on demand. They also advise reserving the bedroom for sleep alone, since using the bed to study, scroll through a phone, or watch videos teaches the brain to associate that space with ③wakeful activity rather than rest. Physical environment matters as well: a cool, dark, and quiet room tends to produce ④deeper sleep than one that is warm, bright, or noisy. None of these individual habits guarantees a good night's sleep on its own, but together they form a routine that gradually trains the body to expect and enter sleep more easily, much the way a ⑤consistent set of cues trains an athlete's body to perform at a certain time each day.

For decades, athletes were taught to stretch a muscle and hold the position before any competition, believing that this practice alone would prevent injury. Recent research, however, has complicated that assumption considerably, since static stretching, in which a muscle is held at its longest length for an extended period, can actually _______________. Dynamic stretching, which involves controlled, repeated movement through a joint's full range of motion, appears to prepare muscles for activity without this problem.

Across many countries, high schools begin classes early in the morning, often before eight o'clock. This schedule assumes that teenagers can simply go to bed earlier to compensate, but biology tells a different story. During adolescence, the body's internal clock shifts later, delaying the release of melatonin until well after ten at night. As a result, most teenagers are not physiologically ready to fall asleep until much later than younger children or adults. When early start times force them to wake before their bodies have completed a full sleep cycle, the mismatch accumulates into a chronic sleep debt that affects concentration and mood throughout the school day. Researchers who study this mismatch argue that _______________. Some school districts that delayed their start times by thirty minutes reported improvements in attendance, suggesting that the timing of the school day matters more than commonly assumed.

Exercise does far more than strengthen muscles and the heart; it also produces measurable changes within the brain itself. (A) Interestingly, aerobic activities such as running or swimming appear to produce more pronounced cognitive benefits than purely strength-based training, though the precise biological reasons for this difference remain an active area of investigation. (B) Studies comparing physically active students to sedentary peers have repeatedly found that the active group performs better on tests of attention and problem-solving, even when the exercise session ends well before the test begins. (C) During sustained physical activity, the body releases a protein called brain-derived neurotrophic factor, which supports the growth of new neurons and strengthens connections between existing ones.

After a strenuous workout, muscle fibers experience thousands of microscopic tears, and the body immediately begins a repair process that depends heavily on amino acids, the building blocks that protein supplies. (A) Waiting too long to eat, however, can slow this recovery, since a muscle's sensitivity to amino acids gradually declines once that window closes. (B) Even so, eating an enormous quantity of protein in a single sitting will not speed things up any further, because the body can only use a limited amount at once, burning or storing the rest. (C) This is precisely why sports scientists recommend consuming protein within a couple of hours after a workout, while the muscle is still especially receptive to it.

This mismatch between internal time and local time is the true source of the problem, not the flight itself. Travelers who cross several time zones in a single flight often arrive feeling exhausted, foggy, and strangely out of sync with the local clock, a condition widely known as jet lag. ( ① ) The discomfort arises because the body's internal clock, which governs sleep, hunger, and alertness, continues to run on the schedule of the departure city even after landing. ( ② ) Realigning this internal clock to a new time zone is not instantaneous; researchers estimate that the body typically needs about one day to adjust for every time zone crossed. ( ③ ) Flying eastward tends to produce more severe symptoms than flying westward, because advancing the internal clock forward is generally harder for the body than delaying it. ( ④ ) Exposure to natural light at the right moments after arrival can help speed up the adjustment, since light is the strongest external cue the internal clock uses to reset itself. ( ⑤ ) Without such adjustments, travelers may continue to experience disrupted sleep and reduced concentration for several days after a long international flight.