Just as you would see physiological changes with training, detraining or reversibility also has its effects. Training adaptations only last as long as the physiological and metabolic demands are placed on the body. Detraining refers to “the bodily effect experienced when one takes an extended break from regular, vigorous fitness training”. When training ceases, so will the training effect and the adaptations that occurred during training are reversed when training stops. Most individuals are unaware of just how profound and rapid these changes can occur, with significant losses in conditioning occurring after 2-6 weeks. If physical activity is completely ceased, training effects are generally lost within 8 weeks, with a reduction rate of approximately one third of the rate of acquisition. How quickly you lose it depends on several factors including your current fitness level, how long you have been engaged in exercise prior to stopping and how long you stop exercising for.
The following are just some of the changes that have been evidenced as a result of detraining:
• decrements in bone mass and bone strength
• a decrease in muscle cross-sectional area and an increase in the number of slow-twitch vs. fast twitch fibres
• decreases in respiratory function
• increase in the amount of carbohydrate used as the predominant fuel source during both maximal and submaximal exercise, with less energy derived from fat
• significant reductions in aerobic fitness
• decreased blood volume leading to a rapid decline in cardiovascular function
• decreased oxygen uptake in the muscles
• higher blood lactate concentrations at a lower percentage of VO2 max (maximal oxygen uptake)
Maintenance of training effects...
Research has shown that you are in fact able to maintain your current fitness level even if you need to adjust or decrease your fitness regime for several months. If this is the case, you need to exercise at approximately 70% of your VO2 max at least once per week.
Majority of individuals will need to stop exercising at some stage in their lives due to unforeseen circumstances such as work commitments, travel arrangements, illness or injury, etc. Attempting to retrain after a detraining period may seem difficult and challenging, especially if the individual attempts to return to the same level of training, as the body struggles to reach its past level of fitness. Therefore, it is important to avoid prolonged periods of complete physical inactivity to no more than 2-3 weeks or incorporate some form of maintenance training where possible.
