How long does it take to be considered sedentary? What are the harms of sitting for a long time?

How much time do you spend sitting during the day?

Now, whether you are a student or an office worker

In a day, in addition to commuting to school and get off work

Sitting most of the time

A study by the American Heart Association states that

"Sitting for 8 hours a day without exercise increases the risk of stroke by 7 times"

0 1How long is considered sitting for a long time?

The "Dietary Guidelines for Chinese Residents" summarizes sedentary and static behaviors together, which refers to sitting or lying down for a long time except sleeping, including all forms of sitting or lying down, such as sitting for a long time to work, use a computer, watch TV, play with a mobile phone, etc.

Doctors say that as metabolic research continues to advance in various fields, if you sit for more than 30 minutes at a time, your body's metabolism will actually change slightly. Therefore, some people believe that sitting for more than 30 minutes may have an impact on human health.

0 2What are the dangers of sitting for a long time?

Injury

When sitting for a long time, the weight of the human body will be concentrated on the lumbar sacral area. This uneven pressure distribution can easily cause strain and pain in the waist and back muscles. Long-term use can even lead to decreased elasticity of the intervertebral disc tissue and bone hyperplasia of the spine.

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People who sit for long periods of time and do little exercise have slower blood circulation, increased blood viscosity, and weaker myocardial contraction. Over time, arteriosclerosis, coronary heart disease, etc. will follow.

Brain damage

Sitting still for a long time will slow down blood circulation, which will lead to insufficient blood supply to the brain, damage the mind and brain, and cause mental depression, which is manifested as physical fatigue, mental listlessness, and constant yawning.

Bone injury

Sitting for a long time will keep the neck, shoulders, waist and back in a fixed position, and the intervertebral disc and interspinous ligament will be in a tense and rigid state for a long time, which will cause stiffness, soreness and pain in the neck, shoulders, waist and back, or difficulty in pitching, turning and bending. In particular, improper sitting posture can easily cause hunchback and bone hyperplasia.

Upset stomach

Sitting for a long time without whole body exercise will weaken gastrointestinal motility and reduce the secretion of digestive juices. Over time, symptoms such as loss of appetite, indigestion and abdominal distension will appear.

0 3How to reduce the harm of sitting for a long time ?

A study in the British Journal of Sports Medicine in 2021 pointed out that there is an optimal formula to offset the harm of sitting for a long time through exercise. The researchers found that the 1:3 "package" ratio is the best, that is, for every hour of sitting, 3 minutes of moderate to vigorous exercise or 12 minutes of light exercise is the best way to improve health and reduce the risk of premature death.

Exercise whenever you can. You can set an alarm on your phone, or use a timer, and get up and walk around every half hour, drink some water, or go to the bathroom. You can also do cervical spine exercises or upper limb exercises while walking to relax your muscles.

22 minutes of medium to high intensity exercise. For people with decent physical fitness and regular exercise habits, you can try medium to high intensity exercise after warming up.

Moderate-intensity exercise : heart rate is generally between 100 and 140 beats per minute, you can feel sweating, your breathing is relatively rapid, and you feel a little strenuous. For example: brisk walking, jogging, cycling, Tai Chi, tennis doubles, etc.

High-intensity exercise : heart rate is greater than 140 beats/minute, at this time, you will sweat profusely, your heartbeat will be violent, you will be out of breath, and you will feel out of breath. For example: fast running, high-speed cycling, fast high leg raises, deep squats and jumping jacks, HIIT (high-intensity interval training), fast-paced aerobics, fast mountain climbing, climbing stairs, singles tennis, etc.

Keep walking every day. If time permits, you can do more exercises such as brisk walking, jogging, badminton, swimming, etc. to improve the health risks caused by sitting for a long time.

A study published in the British Journal of Sports Medicine in 2024 found that walking more than 2,200 steps a day can reduce the risk of death and cardiovascular disease, regardless of how long you sit. The greatest risk reduction is about 10,000 steps a day. On your way to and from get off work, you can walk or ride a bike instead of driving, or walk an extra stop.

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