Where are the biceps muscles located?
AnswerThe front of the upper arm
The biceps brachii sits at the front of the upper arm and bends the elbow.
Fitness · Facts & stats
Fitness facts & stats
7 fact-checked facts about fitness and the science of exercise, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What does HIIT stand for?
AnswerHigh-intensity interval training
HIIT alternates short bursts of hard effort with periods of rest or easy movement.
Going deeper
Which molecule directly supplies energy for muscle contraction?
AnswerATP
Adenosine triphosphate (ATP) releases energy when broken down, powering muscle fibers.
Slow-twitch muscle fibers are best suited to which activity?
AnswerLong endurance efforts
Slow-twitch fibers resist fatigue and use oxygen efficiently, making them ideal for endurance.
What does VO2 max measure?
AnswerThe maximum rate the body can use oxygen during exercise
VO2 max is the highest rate of oxygen use during intense exercise, a key marker of aerobic capacity.
Expert level
Which two proteins slide past each other to make a muscle contract?
AnswerActin and myosin
In the sliding filament model, myosin heads pull on actin filaments to shorten muscle fibers.
In an isometric exercise, what happens to the working muscle?
AnswerIt contracts without changing length
Isometric holds like a plank or wall sit create tension without visible joint movement.
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