Scientific Papers and Revision Lecture

Question 1

What study explored sleep deprivation?
What were the findings?

Answer 1

Rae et al 2017

• caused a decrease in PPO
• Caused increased sleepiness
• Decreased motivation to train

Question 2

What is non-functional overreaching?

Answer 2

When the individual is rested but the performance has no improvement after resting

Question 3

What is functional overreaching?

Answer 3

After the rest, able to recover and perform well

Question 4

What is overtraining?

Answer 4

Training beyond the overreaching threshold causing a decrease in performance after training.

A long recovery period is needed to recover from the effects of overtraining

Question 5

What study investigates the release of Growth Hormone?
What were the findings?

Answer 5

Kanalay et al 1997

GH concentrations were greater in the delayed and sequential exercise bouts compared to the control groups

There was no differences in the GH release during sleep

Question 6

Circadian Timing of:
a) Melatonin
b) CBT
c) Cortisol

Answer 6

a) Rises at dark onset - peaks at 2-4am
b) CBT gradually rises during the day - peaks at 6PM
c) Cortisol climbs gradually and peaks at waking time
- Has a high degree of impact relating to stress

Question 7

Chronotype influence on Sleep duration
(Work vs Work-free days)

Answer 7

Early Chronotype
- More sleep during work days
- Less sleep time during work free days (due to social activities)

Late Chronotype
- Less sleep during work days
- More sleep during work free days (to recover from sleep debt)

Question 8

What is the Primary Zeitgeber to circadian rhythm?

Answer 8

Light

Question 9

What is the photoreceptor that is sensitive to light?

Answer 9

Melanopsin - blue light triggers the melanopsin cells

Question 10

What controls the release of Melatonin?

Answer 10

Pineal Gland

Question 11

How does light impact on alertness and mood?
(Hormone related)

Answer 11

Light causes the SCN to supress the pineal gland and supress the melatonin secretion

Supression of melatonin causes an increased alertness and mood

Resting the clock

Question 12

How long does it take to synchronise the peripheral clocks?

Answer 12

4-12 hours

Question 13

What is the basis of the 24 hour rhythm
(4 words)

Answer 13

Transcriptional-Translational Feedback Loops

Question 14

What does daylight do to clock genes?

Answer 14

Causes the expression of the Per and Cry genes to activate the transcriptional-translational process to increase the protein synthesis

Question 15

What does nighttime do to clock genes?

Answer 15

Dark onset supresses clock gene expression to allow the body to prepare and rest/recover

Blocks the Clock:BMAL1 transcriptional activity to allow for sleep to occur

Question 16

3 Features of the molecular clock

Answer 16

1) Entrainment - to the light dark cycle
2) Endogenous pacemaker - Clock internal to organism
- Can keep time without the presence of external cues
3) Temperature compensation - not affected by external changes in temperature

Question 17

What is the phase angle of entrainment?
What chronotype has a larger angle of entrainment?

Answer 17

The time interval between the timing of the body clock (DLMO) and the timing of an external cue (e.g. Mid sleep time)

Early Chronotypes have larger angles of entrainment due to earlier DLMO

Question 18

What study looked at the time of day variation in sports performance?
What did it show?

Answer 18

Facer-Childs 2015

Early Chronotypes Performed best 6 hours after awakening

Late Chronotypes performed best 12 hours after awakening

Question 19

When is the biggest loss in height and how much height do you lose within 3 hours?

Answer 19

Biggest loss in height occurs in the first hour (50%)

80% loss in height within 3 hours

Question 20

What time is the greatest trunk flexibility?

Answer 20

PM

Question 21

Who conducted the study ‘Time of day variation in VO2max’
What were the findings?

Answer 21

Knaier et al 2019
There is a diurnal variation to VO2 Max - 4-7pm was the peak in VO2 max

The diurnal variation was 2.5 times higher than that of the day to day variation in VO2 max performance

Question 22

Is AM or PM better for lifting larger loads?

Answer 22

PM you can lift heaver loads however fatigue faster

Question 23

What time does cough and dyspnea worsen?

Answer 23

Approx 4am

Question 24

When should you take short acting statins?

Answer 24

In the evening

Question 25

When should you consume Long Acting statins?

Answer 25

Any time of day
Used in cases of polypharmacy

Question 26

Is there diurnal variation to Major depressive disorder?

Answer 26

Yes, Negative affect increases in the morning (harder to control mood in the morning)

Normal Shaped pattern for positive affect