Cardio exercise can offer valuable benefits but you may be unsure about the duration. Find out whether 45 minutes of cardio a day is a good idea.
The first thing to note is that 45 minutes of some types of cardio a day will currently be too much for many people. Their bodies will not be able to recover from the challenge yet.
In that case, working up to this exercise routine with easier workouts can help.
That being said, if your body can handle 45 minutes of cardio a day it can offer benefits like better cardiovascular health, help you burn calories, improve your mood, and potentially be enough to lose a nice amount of weight.
This routine is also good in the sense that it can help you reach many of the exercise guidelines including the one of the Office of Disease Prevention and Health Promotion for cardiovascular exercise a week.
At the same time, you want to keep in mind that also implementing resistance training is generally recommended for optimal health. Additionally, shorter and more intense cardiovascular sessions can be valuable too.
Is 45 minutes of cardio per day good?
45 minutes of cardio a day will be a big achievement for many people. However, likely more importantly, the questions are whether this is actually a smart idea, too much, or not enough.
Before going into the specific benefits and potential weight loss effects of this routine, I will go over what it means for general health.
The Office of Disease Prevention and Health Promotion recommends the following exercise guidelines for adults (1):
- Moving more and sitting less throughout the day
- At least 150 to 300 minutes of moderate-intensity aerobic activity or 75 to 150 minutes of vigorous-intensity aerobic activity a week. Preferably spread throughout the week.
- You can gain additional health benefits by engaging in physical activity beyond the equivalent of 300 minutes of moderate-intensity physical activity a week.
- Muscle-strengthening activities of moderate or greater intensity that involve all major muscle groups on 2 or more days a week.
With these guidelines in mind, you can start to think about whether 45 minutes a day is too much or not enough for your health.
Is 45 minutes of cardio a day too much?
First of all, 45 minutes of cardio a day comes down to 315 minutes of exercise a week.
If you do the cardiovascular workouts at a moderate intensity, you get just above the “at least” range of the guidelines which could benefit your health even more according to the ODPHP.
However, you need to keep in mind that these are rough general recommendations. Going straight to these numbers will not be healthy for every single individual.
Additionally, there can be big differences in cardio workouts. Walking in the park is a lot easier on your body than running through hilly terrain.
In simpler words, for a good amount of people, 45 minutes of certain types of cardio a day will be too much. Their bodies will not be able to deal with it (yet) and they can get the side effects of overtraining.
Some signs that you could be overtraining include reduced sleep quality, big reductions in exercise performance, general fatigue, elevated heart rate throughout the day, etc.
Additionally, people who do resistance training with the goal of building muscle generally want to stay in a small calorie surplus. Doing 45 minutes of cardio a day could be too much to achieve this calorie surplus.
Is 45 minutes of cardio enough?
You may also be concerned about the opposite, whether 45 minutes of cardio is enough and how many days you need to implement this.
If you want to stick to moderate-intensity cardio, you have to implement at least 4 to 5 days of 45 minutes of cardio a week to reach the Office of Disease Prevention and Health Promotion guidelines.
People who are interested in high-intensity cardio can reach the weekly guidelines with 2 to 3 days of 45 minutes of cardio.
Next, the ODPHP also recommends 2 or more days of resistance training (lifting weights) a week.
While you can do some cardio after weights if you are short on time, 45 minutes is likely not necessary or optimal for people who already do a lot of cardiovascular training on the other days.
Besides general health, whether 45 minutes of cardio a day or less often is enough for more specific goals like losing weight will be discussed in the next section.
What does 45 minutes of cardio do for your body?
As long as you are not overtraining, 45 minutes of cardio can offer valuable benefits for your body. You can find some of the most important ones below.
Can you lose weight doing 45 minutes of cardio a day?
Losing or controlling weight is a popular reason to implement more cardio exercise for many people and for a good reason.
Excess body fat can cause a variety of negative effects on health and many people don’t like the way it looks.
Luckily, this excess body fat can also go away again by making sure your body needs more energy than is coming in from food. In a situation like that, your body turns to these energy stores like body fat to make up for the difference.
One way to make this happen is moving more intensely than usual with cardiovascular exercise. These more intense movements require more energy and in turn, can potentially lead to weight loss.
Besides this more high-level explanation, you may also want to know about more specific numbers that tell you how much weight you can lose by doing 45 minutes of cardio a day.
Here are some rough estimations for how many calories a 155-pound (70 kg) individual burns by doing different types of cardio for 45 minutes (2):
- Walking (3 mph = 4.8 kmh): 192 calories
- Rowing machine (moderate effort): 264 calories
- Bicycling (12 mph = 19.3 kmh): 439 calories
- Swimming crawl (medium speed = 50 yards/minute): 456 calories
- Running (6 mph = 9.7 kmh): 538 calories
One pound (0.45 kg) of body fat is about 3500 calories. You can use this to estimate how much weight you can lose by doing 45 minutes of cardio.
For example, if this 155-pound (70 kg) individual would row at a moderate effort for 45 minutes a day for a week, he/she would burn around 1848 calories or about 0.53 pounds (0.24 kg) of body fat if all other lifestyle habits stay the same.
You do want to keep in mind that you can also lose weight without exercise. Your other lifestyle habits like nutrition play a big role in achieving this fitness goal.
Additionally, as you lose more weight, you will burn fewer calories with the same habits. This means you need to make changes to your routine over time to keep seeing results.
Can improve cardiovascular health
As the name implies, cardio is a category of activities that mainly challenge your cardiovascular system which includes your heart, lungs, and blood vessels.
These parts of your body are responsible for extracting oxygen from the air and moving this oxygen, nutrients, and waste products around.
During cardio exercise, these things need to happen at a higher rate and in turn, your cardiovascular system has to work harder.
One thing to keep in mind is that improving cardiovascular health is not only about duration.
A small study divided 25 participants into three groups. The first group did three sessions of 3 x 20-second all-out cycling sprints with 2 minutes of light cycling in between a week for 12 weeks.
The second group did 45 minutes of continuous cycling at 70% maximal heart rate three times a week for 12 weeks. Lastly, the third control group did not train.
In this study, they measure that the peak oxygen uptake, insulin sensitivity, and VO2 peak improvements were similar in both exercise groups (6). Even though the first group spent a lot less time working out.
Your mood can improve
The health of your body also influences your mood and thoughts in a few ways.
First of all, if your body is at a fitness level where 45 minutes of cardio a day is healthy, this routine can help you avoid conditions that make you feel worse.
Lastly, you will likely feel good about doing something that can feel challenging in the moment but is good for you in the long term.
How to work your way up to 45 minutes of cardio
As mentioned before, 45 minutes of certain types of cardio a day or even on one day is currently too challenging for many people.
That being said, in most cases, there is a way to work up to these 45 minutes in a safe and healthy way.
The two main things to keep in mind to achieve this goal are taking it slowly and choosing what cardio you do smartly.
First of all, people who are not used to working out and have extra pounds to lose generally don’t want to go straight to running.
In a situation like that, low-impact exercises like walking, swimming, and using an elliptical machine are typically smarter.
Secondly, to challenge your body to safe extents it is a good idea to start too easy rather than too hard.
You can start with something like 10 minutes of walking a week and if that goes well, slowly increase the duration and intensity of the cardio exercise in your routine.