Overtraining and exercise recovery

Question 1

What is OR and OT?

Answer 1

• Both characterised by:
  ○ Performance decline
  ○ High levels of fatigue
  ○ Psychological + hormonal disturbances
• Seen as a continuum involving disturbance, adaptation + finally maladaptation of the hypothalamic-pituitaryadrenal (HPA) axis – blunting of ACTH, no change in cortisol
• Overreaching is a continuum of overtraining

Question 2

Differences between OR and OT?

Answer 2

• Distinction difficult to establish
• OT symptoms more severe than those of OR
• A discriminating factor:
  ○ Restoration of perf capacity
  § OR: several days to several weeks
  § OT: several weeks or months
• Adrenocorticotrophic hormone & prolactin: sensitive markers for discriminating b/w OR + OT in TOP test (2-bout maximal incremental exercise test, separated by 4h)
• If an athlete suffers from OR = in the first test there was/is no detectable ACTH + prolactin but in the 2nd test there was a huge rise in these 2 hormones
• On the other hand, for OT = in the first test they found that the 2 hormone levels shoot up but in the 2nd test there was a blunting of these 2 hormones

Question 3

A case of over-training syndrome (OTS)

Answer 3

• An international alpine skier, who talent transferred to sprint cycling, showed improved perf over 6-months of intense training/ comp, despite suboptimal sleeping (< 6h/night sleep + shift work) & sub-optimal eating behaviour.
  Subsequently, perf declined + OTS was diagnosed.
• Three months’ abstinence from intense training w/ sleep recovery was required for the athlete’s return to untrained baseline levels –> highlights the integral role of sleep disturbance + circadian disruption of the sleep-wake cycle (+ other bodily functions) as a mediator of + predictive marker for OTS.

Question 4

The Overtraining Syndrome

Answer 4

REFER TO IMAGE

Question 5

Shared signs & symptoms between people with sleep disturbance and overtrained athletes:

Answer 5

• Increased perceived effort
• “heavy legs”
• Muscle soreness
• ↑ fatigue
• mood disturbance/ depression
• Sleep disturbances

Question 6

The role of sleep in training adaptations -

Answer 6

why as an athlete do you need more sleep = during sleep period there are anabolic hormones that are released (are the building hormones)

Anabolic hormones
* Two superfamilies of “anabolic giants” in cellular growth + repair:
○ 1. testosterone = far higher in males than females, growth hormone (GH)
○ 2. the insulin-like growth factor (IGF)
○ Both:
§ exert muscle-anabolic effect = help you repair + synthesise proteins in your muscles
§ act synergistically + independently

Catabolic hormones = catabolism = breaking down, anabolic = building up
* Glucocorticoids
○ Cortisol:
§ exert muscle-catabolic effect = break down muscle
§ stimulates fat + carb metabolism during exercise
○ Important to have cortisol being release while exercising = cortisol helps to supply the substrates that are necessary to produce energy during exercise

Question 7

Growth hormone and IGF-1

Answer 7

• IGF-1 = Is the active one, but growth hormone is also required because when GH is released from your anterior pituitary gland is stimulates the liver to produce IGF-1 + from here it can amplify/regulate skeletal muscle repair + remodelling (muscle building or muscle being broken down)

Question 8

Cortisol pulses during sleep = across the night it starts to increase and peaks in the early morning = is normal however shouldn’t be too much

Answer 8

Cortisol is deactivated during the sleep period to form –> Cortisone

• However cortical pulses continue to stay up + maybe increase in 2 groups of people: athletes that are overtrained + also people w/ insomnia
• Overtraining impairs the conversion process = because in athletes cortisol is not converted into cortisone + same in insomnia people = why have difficulty falling/staying asleep = as there is a lot of cortisol circulating in the blood system

Question 9

Circadian timing of GH and cortisol

Answer 9

• GH has a high peak during the sleep period –> GH released during deep/SWS sleep
• Cortisol has its lowest level during the middle of the night + inclines + peaks first thing in the morning + then it starts to decline but of course if you are exercising during the day you will get peaks of cortisol

Question 10

how may SWS mediate exercise recovery?

Answer 10

SWS
* physical restorative process
* time-locked to growth hormone (GH) release during normal sleep = the release of GH is temporally associated w/ SWS
* GH hormone has an anabolic function = why the release of GH is important particularly during deep sleep

GH’s anabolic effect
* stimulates protein synthesis for tissue restoration, enabling muscle + bone development + repair = w/ protein synthesis produce amino acids which are the building blocks for proteins
* a prerequisite for recovery after intense bouts of training + comp = because of the release of growth hormone