a winter without running the changes in your body will scare you

Exercise is like rowing upstream; not to advance is to drop back.

As the saying goes, 'Train in the coldest days of winter and the hottest days of summer; three days without training sets you back half a year.' One-third of the winter training period has passed. Runners, have you been sticking to your running routine?

Winter training is a crucial phase for forming competitive condition. The best competitive state of an athlete relies on the scientific nature of the winter training plan and its implementation. For running athletes, the focus of winter training is on technique and strength. Technique includes starting techniques and full-course rhythm running techniques, while strength training is characterized by high intensity and diverse methods, primarily aimed at developing the strength of the hip muscle group, with an emphasis on explosive strength and balanced strength training.

Here's the problem: in cold weather, many runners feel too weak to exercise. But do you know how much you lose by skipping winter training? When a body accustomed to exercise suddenly becomes inactive, cardiovascular function, muscle endurance and strength, and flexibility all decline to varying degrees.

Two weeks

Scott Weiss, an exercise physiologist with the American College of Sports Medicine, believes that two weeks is a turning point. At this time, significant physiological changes indicate a decline in fitness. Runners should not underestimate the impact of a 2-3 week hiatus; your speed, endurance, and flexibility will decrease as a result.

The most noticeable decline is in endurance. After two weeks, you will clearly feel less capable during exercise. This is because your VO2 max, which reflects your body's endurance capacity, drops by about 10%. After four weeks of inactivity, it continues to drop by about 15%, and after three months, it drops by 20%.

From another perspective, your body's ability to break down lactic acid also decreases, meaning your lactate threshold drops. When you exercise at your previous intensity, your body can't clear lactic acid as quickly as it produces it. Lactic acid begins to accumulate in your blood, its concentration rapidly increases, making it difficult for you to continue, and your endurance will significantly decline.

Additionally, the muscle fibers you worked so hard to build will atrophy. Research confirms that a two-week break can lead to a decline in muscle mass, capillary size, and density to varying degrees. When you lose your previous training regimen and intensity, the decline in muscle mass will lead to a loss of muscle strength, endurance, and neuromuscular training adaptation. Because without exercise, muscle fibers realize they don't need to store energy, they will store less glycogen, leading to muscle fiber atrophy.

One month

Many signs of bodily dysfunction are not visible to the naked eye.

It is well known that exercise can improve memory and sleep quality, and prevent anxiety and depression. Think back: after stopping running for a month, did you start to feel your sleep quality deteriorate?

This is because running and fitness increase your body's metabolism. After you fall asleep, the hormones produced by your body repair the muscle tissue damaged during exercise, promoting good sleep. Lack of exercise reduces deep sleep, leading to restlessness, poor sleep quality, and potentially causing anxiety or depression.

Moreover, with reduced oxygen intake by the brain and lower dopamine levels after stopping exercise, you become more prone to anxiety and fatigue, which can lead to a dislike of running and fitness, creating a vicious cycle.

Two months

Winter's cold weather greatly increases the demand for calories. Stopping exercise reduces energy expenditure, and if you don't control your diet, you might gain several pounds.

Research shows that two months of fitness training can increase body strength by 46%, but stopping fitness for two months can reduce your body strength by 23%. Of course, these figures are not absolute. If your physical condition was good enough before stopping, the rate and extent of decline in physical function will be slower and less. Even for competitive athletes, stopping professional training but maintaining low-intensity exercise can increase body fat percentage by 12% after 5-8 weeks, with weight and waist circumference also increasing, and muscle mass significantly decreasing.

For running, the entire winter training period lasts about three months, from early November to the end of January. If you completely stop exercising during these three months, your performance might be worse than expected when the spring retraining period arrives. While you are standing still, other runners are still training, so your stagnation is like rowing upstream; not to advance is to drop back. So, get moving for the remaining two months!