Short answer: Build endurance and keep it. Health has become a 6.8 trillion dollar business because we move less: 1 in 3 adults now do not move enough. The lowest fitness carried 5 times the risk of death of the fittest. The fix is easy runs, week after week.
The short version
- Adults who do not move enough rose from 23.4% in 2000 to 31.3% in 2022.
- The lowest fitness carried about 5 times the risk of death of the fittest.
- More fitness was better, with no top limit.
- Fitness fell 7% after 3 weeks off, and 16% by 8 weeks.
- After 12 weeks off, trained people were still fitter than the untrained.
Health is now a very big business
People spent 6.8 trillion US dollars on wellness in 2024, by the count of the Global Wellness Institute. That was 7.9% more than the year before. Gyms, supplements, wellness apps, diet plans and fitness gadgets all sit inside that number.
Everyone calls this a boom. For a doctor, it is not good news. A market grows when there is a need, and here the need is that our bodies are moving less and getting weaker.
It grows because we move less
Machines and AI do more of our work, and more of it is done sitting down. A count from 507 surveys in 163 countries found that 23.4% of adults did not move enough in 2000. By 2022 it was 31.3%. That is 1 in 3 adults.
Not enough means under 150 minutes of moderate activity a week, or 75 minutes of hard activity. Brisk walking counts as moderate. So health is big business because so many of us fall short of a simple weekly target.
Low fitness costs more than you think
In a study of 122,007 people who did a treadmill test and were followed for about 8 years, those with the lowest fitness had about 5 times the risk of death of the fittest group. Fitness here means how long and how hard they could go on the treadmill. This shows a link, not proof that low fitness alone caused the deaths.
The hopeful part: fitness is something you can change. The same study found no top limit. More fitness was better, all the way up.
Start building endurance
Keep most runs easy, slow enough to talk. Aim for about 150 minutes a week, the line used in the world count. Spread it over most days. Start where you are and add a little each week.
Building endurance is a long game. Steady weeks beat one hard week. If you have a heart condition or have been inactive for a long time, check with your doctor before you start.
If you have it, keep it
Fitness fades when you stop. In a small study of 7 trained athletes who stopped training, fitness fell 7% in the first 3 weeks. By 8 weeks it was 16% lower and then held there. The first drop came because the heart pumped less blood with each beat.
Not all was lost. After 12 weeks off, they were still fitter than people who had never trained. So a break is not the end. Lace up and start again, a little at a time.
Your questions, answered
Why should I build endurance?
Because fitness is tied to how long you live. In 122,007 people, the lowest fitness carried about 5 times the risk of death of the fittest, and more fitness was better with no top limit (Mandsager 2018). So every step up counts.
How much running is enough to start?
Aim for about 150 minutes a week of easy, moderate effort, the line used to count who moves enough (Strain 2024). Easy runs where you can still talk count. Build up a little each week, and keep most runs easy.
How fast do I lose fitness if I stop running?
In 7 trained athletes, fitness fell 7% in the first 3 weeks and 16% by 8 weeks (Coyle 1984). The early drop came from the heart pumping less blood with each beat. Keep at least some easy runs going.
I took a long break. Is it all gone?
No. After 12 weeks off, the athletes were still fitter than people who had never trained (Coyle 1984). Start again with easy runs and add a little each week. Building endurance is a long game, so be patient.
Build Your Endurance Now
Easy runs, most days, week after week. Read the heart side on Cardiac Rehab: health is big business because we move less.
References
- Strain T, Flaxman S, Guthold R, et al. National, regional, and global trends in insufficient physical activity among adults from 2000 to 2022: a pooled analysis of 507 population-based surveys with 5.7 million participants. Lancet Glob Health. 2024. pubmed.ncbi.nlm.nih.gov/38942042
- Mandsager K, Harb S, Cremer P, et al. Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA Netw Open. 2018. pubmed.ncbi.nlm.nih.gov/30646252
- Coyle EF, Martin WH, Sinacore DR, et al. Time course of loss of adaptations after stopping prolonged intense endurance training. J Appl Physiol. 1984. pubmed.ncbi.nlm.nih.gov/6511559
- Global Wellness Institute. Wellness Economy Statistics & Facts (Global Wellness Economy Monitor 2025). globalwellnessinstitute.org/press-room/statistics-and-facts