Detraining

Question 1

detraining definition

Answer 1

Ceasing training or reducing training volume decreases physiological and performance capacities
- Short term detraining (<4 weeks) can result in significant decreases in endurance and strength performance

Question 2

aerobic changes

0-12days of detraining

Answer 2

4% dec VO2 max in 4 days

6-7% dec in 12 days

d/t dec in SV assoc. with 6-7% dec PV

HR and a-vO2 difference remained unchanged

Question 3

aerobic changes

1 week of bed rest

Answer 3

6-7% decrease in VO2 max

6-7% decreases in total haemoglobin

6-7% decrease in blood volume

Question 4

aerobic changes

21-84 days of detraining

Answer 4

Most training benefits are lost within 4 weeks of cessation of training

14% dec VO2 max in 4 weeks

20% dec VO2 max in 8 weeks

Question 5

complete detraining effect

Answer 5

(may take several months)
dec Q
dec SV
dec Ventricular mass 
inc Submax HR
dec a-vO2 difference (>4 weeks)
dec Capillary density
dec Fibre CSA
dec Oxidative enzyme capacity

Question 6

strength/power changes

Answer 6

studies indicate variables rates
- 10-18 weeks training followed by 12 weeks cessation resulted in 68% decrease in strength.
- 4 weeks cessation results in 15% decrease in power
Vs
- 31% decrease in strength following 30 weeks detraining

Question 7

strength changes

Answer 7

Largest decrease occurs in the first 4 weeks
o 6-10% dec 1RM
o 14-17% dec peak power output
Due to:
- dec EMG activity
- Atrophy in Type II (fast-twitch) fibres
- dec neural drive (motor unit recruitment)

• Transition phase after competition is important to maintain both aerobic and strength changes

Question 8

maintenance

Answer 8

A number of beneficial training effects can be maintained for several months with a reduced training load

• Decreasing training frequency from 3 to 2 days per week while maintaining intensity, maintains VO2 max for 10 weeks
• Decreasing from 3 to 1 days per week does not totally prevent a decline in VO2 max
• Decreasing to 1 day per week results in a 7% decline in VO2 max over 10 weeks
• Reducing training time from 40 minutes per day to 26 minutes per day can maintain training benefits (35%  in time)
• However, reducing to 13 minutes per day may not be sufficient to maintain long term benefits for 15 weeks (~68%  in time)

Question 9

maintenance - strength and power

Answer 9

• Dependent on requirements of the sport
• Recovery must be prioritised for team sports with weekly playing requirements
• Specific training stimuli should be maintained
• Typically 1-4 sessions pw
  o ~2 (maximum 4) Exercises
  o Focus on prime movers
  o 20-40mins per session

Question 10

retraining

Answer 10

• There appears to be little indication of a benefit or positive transfer from one training period to another
• Possibly accelerated retraining rates in previously highly trained athletes (Olympians) after a long lay-off (This may be due to genetic predisposition)