By Brent Bishop (@I_AmBishop)

We see it again and again: the summer is over, fall comes to an end, swimsuits are stowed away, and exercise frequency begins to decline. This scenario happens to so many people over the winter months, which can bring about discouragement as the warmer seasons approach once again. If this sounds familiar, you may want to re-think your winter training strategy now to avoid some serious setbacks in the New Year.

Aside from unwanted weight gain, there are many physiological changes that take place when you stop exercising for a lengthy duration. The degree of change depends on a variety of factors such as age, type of exercise, fitness level, and how long you had exercised prior to stopping. We’re going to examine three areas that suffer the most when you cease regular activity — and it’s not just the numbers on the scale.

Cardiovascular

Generally speaking, cardiovascular fitness begins to decline more rapidly than strength. In fact, a significant reduction in V02 max can be noticed within two to four weeks of stopping a regular conditioning routine. On top of that, the heart’s ability to pump blood more efficiently declines, your muscles’ capacity to process oxygen drops, and your body becomes less efficient with its metabolic processes. Capillary density also drops, impacting circulation efficiency. Additionally, mitochondrial volume is reduced, impacting ATP production, therefore affecting muscle contractile efficiency. Just to add to the list of deconditioning effects, markers such as blood pressure and cholesterol levels will also be impacted as a result of detraining.

Strength

When it comes to your muscular strength, although not nearly as rapid as cardiovascular decline, the deconditioning effects present themselves in a slow reduction of muscle fibre size, reduction in glycolytic and oxidative enzymes (those that help break down glucose and catalyze oxidation, respectively), as well as a drop in neuromuscular adaptations (meaning your brain and body won’t be “speaking” as well). Although there is generally a very minimal loss of strength after a two-week break, muscular endurance tends to be negatively impacted more rapidly, which may be more of a concern for those involved in endurance sports like cycling, swimming, and running.

Immunity

Although exercise itself is a stress to your body and its systems, we do know that at moderate levels exercise can help lower overall stress and therefore have an impact on keeping your immune system operating efficiently. The added benefit of improved circulation allows the cells and substances of the immune system to move through the body freely and perform their functions more competently. Exercise does make an impact on immune system markers such as cytokines, white blood cells, and certain antibodies, which may be linked to some positive benefits in the human immune response. The bottom line: if you stop exercising regularly over the winter months, the result could be increased stress levels and reduced circulatory efficiency, and therefore a higher susceptibility to illness. Not to mention, starting exercise back up after a deconditioned phase could be enough to bring on a cold or flu.

Joint Stability

It should also be cautioned that returning to your routine without decreasing the intensity can wreak havoc on your tendons, ligaments, and joints. It’s not uncommon to go into a workout with the mental belief that you can still lift that heavy or run that hard, the result of which is often a muscle strain, tendonitis, or — worse yet — a significant tendon or ligament tear.

The time required to condition back to your previous state can be significantly longer than the time it took to achieve your deconditioned state. If you plan to be less active this winter, it is a good idea to at least be proactive with a maintenance strategy to maintain a level of exercise consistency. This will not only prevent you from gaining unwanted weight over the holidays, but will also inhibit a significant setback and potential injury come spring.

Brent Bishop is a celebrity trainer, on-air fitness expert, author, and owner of Think Fitness Studios. Visit IamBishop.com.