Biological Rhythms
The Circadian Rhythm
Circadian Effects on the Body
Circadian Rhythms & Exercise
Infradian Rhythms & Exercise
100

This type of biological rhythm lasts less than 20 hours and includes processes like heartbeat and sleep cycles.

What is an ultradian rhythm?
100

This brain structure, located in the hypothalamus, acts as the body's central biological clock.

What is the suprachiasmatic nucleus (SCN)?

100

A physiological system that follows a circadian rhythm.

What is our sleep-wake cycle, or hormone secretion, or body temperature, or metabolism, or cardiovascular health?

100

Most forms of exercise peak in performance between afternoon and early evening, coinciding with a peak in this physiological factor.

What is core body temperature?

100

The most well known infradian rhythm in women.

What is the menstrual cycle?

200

This biological rhythm lasts between 20 and 28 hours and includes the sleep-wake cycle in humans.

What is the circadian rhythm?

200

The circadian rhythm is influenced by many zeitgebers, but what is the strongest one?

What is light?

200
This hormone, which promotes sleep, increases at night and decreases during the day.

What is melatonin?

200

This type of exercise peaks in the early afternoon due to optimal fine motor control.

What is technical skill-based exercise?

200

The phase of the menstrual cycle best for resistance training due to high estrogen levels

What is the late follicular phase?

300

The length of the human circadian rhythm is slightly longer than 24 hours. How long is it exactly?

What is 24.18 hrs (or 24 hrs and 11 min)

300

Clock genes regulate the circadian rhythm through this type of biological loop, in which they inhibit their own expression. 

What is a negative feedback loop?

300

This stress hormone peaks in the morning to help wake you up and declines throughout the day.

What is cortisol?

300

Long-duration endurance exercise performance is best at this time of day.

What is the morning?

300

This hormone, highest in the late follicular phase, helps protect muscles from damage.

What is estrogen?

400

These external cues, such as light and temperature, help regulate biological rhythms.

What are zeitgebers?

400

Although the SCN is the body's master clock, these clocks exist in tissues like muscle and adipose tissue, and have influence over metabolism and other physiological functions.

What are peripheral clocks?

400

Blood pressure and heart rate are highest at these times.

What is the morning and afternoon?

400

Higher core temperature in the afternoon strengthens bonds between these two muscle proteins, improving contractions.

What are actin and myosin?

400

Time to exhaustion is reduced during endurance exercise in the mid-luteal phase due to this factor.

What is a higher core body temperature?