If you’re a seasoned athlete (training consistently over a period of a year or more), don’t worry about taking a training break of up to two weeks; your fitness losses will not be too large, and you will regain them relatively rapidly. However, fitness losses for novice trainers or those with a low fitness base will be proportionately greater and harder to recoup.
For breaks of over two weeks, you’ll need some kind of intense training stimulus such as HIIT to avoid a bigger decline in your fitness. Perform 7 x 30-second intervals, it’s just as effective as 3 x 20-minute hard efforts.
Perform any interval training in a manner that most closely replicates the type of event you’re preparing for (sometimes referred to as ‘specificity of training’). This means that if you’re a cyclist, performing intervals on your bike will give you the best adaptation and fitness gains. Runners, on the other hand, should run!
During any period where you drastically cut down on training volume, remember you will also need to curtail your calorie intake in order to prevent the performance-blunting effects of increased body fat. Emphasis on high quality proteins, fruits and vegetables and a reduction in carbohydrates, even the whole unprocessed ones for the fact that levels of activity are much lower than norm.
If time is tight, maximizing convenience and opportunities to train is key. A ready set up stationary bike, turbo trainer or treadmill in the house or garage can make all the difference.