90 to 120 minutes per week appears to be the sweet spot
Over thirty years and across nearly 150,000 lives, Harvard researchers have arrived at a quietly remarkable finding: the human body appears to ask for very little in exchange for a meaningful extension of life. Between ninety and one hundred twenty minutes of strength training each week — less than the length of a film — reduces the risk of death by thirteen percent, and when paired with aerobic movement, that protection deepens to fifty-eight percent. The study, published in the British Journal of Sports Medicine, is less a prescription than a reminder that longevity is not reserved for athletes, but for those who move with modest, consistent intention.
- Trinta anos de dados e quase 150 mil participantes apontam para uma janela surpreendentemente estreita: entre 90 e 120 minutos semanais de musculação representam o pico de proteção contra a morte — e ir além disso não acrescenta nada.
- O risco de morte por doenças cardiovasculares cai 19% e por doenças neurológicas cai 27% com o treino de força no nível ideal, revelando que levantar peso protege muito além dos músculos.
- A combinação de treino de força e exercício aeróbico em níveis elevados reduz a mortalidade em até 58%, sugerindo que as duas modalidades se potencializam mutuamente de forma que nenhuma alcança sozinha.
- Para quem sente que não tem tempo, o estudo oferece alívio: menos de 13 minutos por dia já é suficiente para capturar benefícios reais — a barreira não é atlética, é de hábito.
Por três décadas, pesquisadores de Harvard acompanharam os hábitos de exercício de mais de 147 mil pessoas, registrando a cada dois anos quanto tempo dedicavam à musculação, a exercícios com o próprio peso e a atividades aeróbicas. A idade média dos participantes era 54 anos ao entrar no estudo, e ao longo do período, 35.798 deles morreram.
A análise revelou um padrão claro: quem praticava entre 90 e 119 minutos semanais de treino de força tinha 13% menos risco de morrer por qualquer causa em comparação com quem mal se exercitava. Doses menores também ajudavam — de 1 a 59 minutos reduzia o risco em 7%, e de 60 a 119 minutos, em 11%. Acima de 120 minutos semanais, porém, o benefício não aumentava mais.
Os efeitos foram especialmente marcantes para causas específicas de morte: o treino de força no nível ideal esteve associado a 19% menos risco de morte cardiovascular e 27% menos risco de morte por doenças neurológicas. O músculo, ao que tudo indica, protege sistemas muito além dele mesmo.
O achado mais expressivo, no entanto, veio da combinação. O exercício aeróbico sozinho já reduzia a mortalidade entre 26% e 43%. Mas quem praticava altos níveis de ambas as modalidades juntas alcançava uma redução de até 58% — um efeito sinérgico que sugere que força e resistência se amplificam mutuamente. A mensagem final do estudo não é que é preciso se tornar atleta, mas que menos de 13 minutos diários de treino de força, somados a algum movimento aeróbico, podem ser suficientes para mudar o curso de uma vida.
For three decades, researchers at Harvard tracked the exercise habits of over 147,000 people, watching carefully to see which ones lived longer and which ones didn't. The answer, published this week in the British Journal of Sports Medicine, is surprisingly specific: somewhere between 90 and 120 minutes of strength training per week appears to be the sweet spot for extending your life.
The study pooled data from three long-running cohorts—the Health Professionals Follow-up Study, which ran from 1992 to 2022, and two versions of the Nurses' Health Study spanning 2002 to 2021. Every two years, participants filled out questionnaires about how much time they spent lifting weights, doing bodyweight exercises like push-ups and squats, and engaging in aerobic activities such as walking briskly, running, swimming, cycling, or playing tennis. The average participant was 54 years old when they entered the study. Over the three decades of observation, 35,798 of them died.
When the researchers analyzed the relationship between strength training volume and mortality risk, the pattern became clear. People who did 90 to 119 minutes of strength training weekly had a 13 percent lower risk of dying from any cause compared to those who did little or no strength training. Notably, doing more than 120 minutes per week offered no additional protection—the benefit plateaued. Even smaller doses helped: those who managed just 1 to 59 minutes weekly saw a 7 percent reduction in mortality risk, while 60 to 119 minutes brought it down by 11 percent.
The protective effect was especially pronounced for certain causes of death. Strength training at the optimal 90-to-119-minute level was associated with a 19 percent lower risk of dying from cardiovascular disease and a 27 percent lower risk of dying from neurological disease. These numbers suggest that resistance exercise does more than build muscle; it appears to fortify the systems that most commonly fail us.
But the researchers found something even more striking when they looked at what happened when people combined strength training with aerobic exercise. Aerobic activity alone—the kind that gets your heart pumping, whether through running, cycling, or brisk walking—reduced mortality risk by 26 to 43 percent on its own. Yet when people did high levels of both types of exercise together, the mortality reduction jumped to as much as 58 percent. This synergistic effect suggests that the two forms of exercise work in concert, each amplifying what the other accomplishes.
The finding arrives at a moment when many people struggle to fit any exercise into their lives, let alone multiple types. The good news is that the study suggests you don't need to become an athlete to see real benefits. Ninety minutes spread across a week—less than 13 minutes per day—appears sufficient. The researchers noted that people who did strength training tended to be younger, weigh less, and maintain healthier overall habits than those who didn't, which raises the question of whether the exercise itself is the cause of longer life or simply a marker of people already inclined toward health. But the consistency of the findings across three separate populations over 30 years suggests the effect is real. The next question for anyone reading this is not whether to exercise, but how to fit both kinds into a life that already feels full.
Citas Notables
No additional mortality benefit was found beyond 120 minutes of weekly strength training— Harvard researchers, British Journal of Sports Medicine
Strength training at 90-119 minutes weekly was associated with 19% lower cardiovascular death risk and 27% lower neurological death risk— Study findings
La Conversación del Hearth Otra perspectiva de la historia
Why does the study stop at 120 minutes? Why not keep going higher?
The researchers found no additional mortality benefit beyond that threshold. More isn't always better—there's a point where the return diminishes to zero. It's actually reassuring, because it means you don't need to become obsessed to see the benefit.
The 58 percent reduction when combining both types of exercise—that's a huge jump from 13 percent. What's happening there?
The two forms of exercise appear to protect different systems. Strength training builds resilience in muscles and bones, while aerobic work strengthens the heart and lungs. Together, they cover more ground. It's not just addition; it's multiplication.
The study followed people for 30 years. Did they all stick with the same routine the whole time?
No. People reported their habits every two years, so the researchers could see how routines changed. That's actually one of the study's strengths—it captures real life, not a controlled lab setting.
What about the people who did very little strength training but still saw a 7 percent mortality reduction?
Even small doses matter. It suggests that the body responds to resistance work at any level. You don't need to be an athlete to benefit. Just moving against resistance, even minimally, shifts the odds in your favor.
Does this apply to everyone, or are there groups it doesn't work for?
The study included health professionals and nurses—relatively health-conscious populations. We don't yet know if the same 90-to-120-minute window holds for people with existing health conditions or very different lifestyles. That's the next question.