Most adults should aim for at least 150 minutes of moderate-intensity cardio per week, or 75 minutes of vigorous cardio. That’s the baseline recommended by the World Health Organization, the American Heart Association, and the CDC. But the right amount for you depends on your goals, whether that’s general health, weight loss, or fitting cardio around strength training.
The Baseline: 150 Minutes Per Week
The 150-minute target is the most widely cited number in exercise science, and it holds up well. Meeting this minimum through moderate or vigorous activity reduces your risk of dying from cardiovascular disease by 22% to 31%. You can split it however works for your schedule: five 30-minute sessions, three 50-minute sessions, or any other combination spread across the week.
Doubling that to 300 minutes per week delivers even greater benefits. The American Heart Association specifically notes that 300 minutes a week is where additional protective effects kick in. There’s a clear dose-response pattern here: people with the highest cardiovascular fitness levels have a 53% lower risk of dying from any cause and a 51% lower risk of dying from heart disease compared to the least fit group. Even reaching an intermediate fitness level cuts all-cause mortality risk by about a third.
How to Tell If You’re Working Hard Enough
Moderate intensity means your heart rate sits between 50% and 70% of your maximum. The simplest way to gauge this without a monitor: you can carry on a conversation, but you can’t sing. Brisk walking, casual cycling, and light swimming all fall into this category for most people.
Vigorous intensity pushes your heart rate to 70% to 85% of your maximum. At this level, you can only get out a few words before needing to catch your breath. Running, fast cycling, rowing, and jump rope are typical examples. Because vigorous exercise taxes your cardiovascular system roughly twice as hard, one minute of vigorous activity counts as two minutes of moderate activity. That’s why the guideline drops to 75 minutes per week if you’re working at higher intensities. You can also mix the two throughout your week.
If Your Goal Is Weight Loss
For losing weight, 150 minutes per week is a starting point, not an endpoint. Research from Harvard found that people exercising 150 minutes per week lost an average of about six pounds and 1.3 inches around the waist. Those who doubled it to 300 minutes lost about nine pounds and 1.6 inches. Even 30 minutes per week produced some reduction in body weight and waist size, but the results scale with volume.
The CDC and American College of Sports Medicine recommend 300 minutes per week of moderate cardio for meaningful weight loss, with even more potentially needed depending on your calorie intake. That’s roughly 45 minutes a day, six days a week, or an hour five days a week. If time is a constraint, higher-intensity formats can help. A meta-analysis of people with overweight and obesity found that high-intensity interval training (HIIT) produced similar improvements in fat mass and waist circumference compared to steady-state cardio, while taking about 40% less time.
Balancing Cardio With Strength Training
If you also lift weights, you’ve probably heard that too much cardio kills your gains. The reality is more nuanced. A 16-week study had one group do resistance training alone and another combine resistance training with four weekly HIIT sessions. Both groups gained similar muscle size, and the molecular processes driving muscle growth (protein synthesis, satellite cell activity) were equally active in both groups. The catch: the group doing both saw smaller strength gains. Muscle grew fine, but peak force development was slightly blunted.
Practically, this means cardio volumes in the range of 150 to 200 minutes per week are unlikely to undermine your muscle-building efforts, especially if you prioritize recovery between sessions. If maximum strength is your primary goal, keeping cardio sessions shorter and separating them from lifting sessions by several hours (or doing them on different days) helps. The American Heart Association also recommends at least two days per week of muscle-strengthening activity alongside your cardio, so the two aren’t competing priorities. They’re both part of the recommendation.
HIIT: More Benefit in Less Time
High-intensity interval training alternates short bursts of all-out effort with recovery periods. Because it pushes you into vigorous territory, a 20-minute HIIT session can replace a 40-minute moderate workout for cardiovascular benefit. Two to three HIIT sessions per week is a common and well-supported frequency. Going beyond that without adequate rest between sessions increases the risk of overtraining, since HIIT places significantly more stress on your muscles and nervous system than steady-state work.
A practical weekly structure might combine two HIIT sessions with two or three moderate-intensity sessions. This gives you the time efficiency of intervals plus the recovery-friendly volume of easier work, and it easily gets you past the 150-minute threshold.
Signs You’re Doing Too Much
More cardio isn’t always better. Overtraining syndrome develops in stages. Early signs include lingering fatigue, performance that suddenly drops off, and persistent soreness that doesn’t resolve with normal rest. As it progresses, it starts affecting your stress response: you may notice disrupted sleep, elevated resting heart rate, or loss of motivation to train. In advanced stages, your body swings in the opposite direction, with an unusually slow resting heart rate (below 60 beats per minute in someone who isn’t typically that low) and elevated stress hormones.
The threshold varies dramatically between individuals. Someone who has been running for years can handle far more weekly volume than a beginner. The key signal to watch is recovery. If you’re sleeping well, your energy is stable, and your performance is gradually improving or holding steady, your current volume is likely appropriate. If you’re dragging through workouts and dreading sessions you used to enjoy, scale back before it compounds.
Recommendations for Adults Over 65
The weekly targets for older adults are the same as for younger ones: 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity cardio, plus at least two days of strength work. The CDC adds one important element for this age group: activities that improve balance, such as tai chi, single-leg exercises, or heel-to-toe walking.
The key difference is flexibility around limitations. If chronic conditions, joint pain, or mobility issues make hitting 150 minutes difficult, any amount of activity still provides benefit. The fitness-mortality relationship doesn’t have a minimum cutoff. Moving from very low fitness to even moderate fitness is where the single largest reduction in health risk occurs, with a 33% drop in all-cause mortality. For someone starting from a sedentary baseline, even short daily walks represent a meaningful improvement.
A Simple Weekly Framework
- For general health: 150 minutes of moderate cardio or 75 minutes of vigorous cardio, spread across at least three days.
- For greater protection: 300 minutes of moderate or 150 minutes of vigorous cardio per week.
- For weight loss: 300 or more minutes of moderate cardio, or a shorter equivalent using higher-intensity formats.
- For muscle building alongside cardio: 150 to 200 minutes per week, ideally separated from lifting sessions, with two to three HIIT sessions as a time-efficient option.
The most important number isn’t 150 or 300. It’s the gap between what you’re doing now and what you could sustain consistently. If you’re currently at zero, 75 minutes a week is a significant upgrade. If you’re already at 150 and feeling good, pushing toward 300 offers measurable additional benefits. Build gradually, pay attention to how you recover, and adjust based on your goals.