There’s no way around it: exercise matters. Whether your plan is to reach your ideal body composition or maintain a healthy one, regular exercise is going to be one of the building blocks of your success.

When you’re planning to change your body composition, there’s a lot to consider. Will you be trying to lose body fat, gain muscle, or both? What dietary plan will help you support those goals? Will you focus on strength training? Resistance training? Both?

Even once you have all those details sorted, you’re still just in the planning stage. What really matters is the execution of your plan, and one of the questions that many people struggle when strategizing how to get started is this: how often should I train?

The question seems simple enough, but these days, it seems like the fitness community can’t make up its mind, especially when it comes to lifting weights.

Some people say that if you train less than 6 days a week, you might as well not train at all. Others claim that training more than once a week is a waste of time at best and overtraining at worst.

Which one is true? Is there a minimum weekly frequency that you must meet for results to come?

Like most polarizing opinions, the answer lies somewhere in the middle. So today, we’re going to take a look at the three common weekly training frequencies: 5 days, 3 days, and 2 days. With a ton of science and some analysis, we’re going to figure out which frequency is your best bet for achieving that ideal body composition.

The 5-Day Training Plan

Philosophy

Let’s get one thing out of the way: the concept of training 5 times a week can be pretty intimidating. That being said, no one ever said that you had to push yourself to your breaking point Monday through Friday.

The goal when working out this frequently is to ‘exercise regularly’, not ‘exercise like an Olympian’. That’s why many people choose to divide up the areas they work out each day, giving particular attention to just one muscle group (or system) while letting the others recover. This type of workout strategy is called a “split,” and is frequently favored by the bodybuilding community.

Typically, 5-day splits are used to target a different major muscle group every day. Here’s one of the more common training plans:

• Monday: Back and Biceps

• Tuesday: Chest and Triceps

• Wednesday: Shoulders and Delts

• Thursday: Legs and Lower Back

• Friday: Biceps and Triceps

Of course, this is just one of the many programs that people have developed. Some people replace a shoulders day with a cardio day, some do abs every day or make a day out of it…the sky’s the limit here.               

Data

But enough about the different ways to stack exercises, we’re here to figure out how a 5-day split can affect your body composition.

Recall that the primary reason for doing a 5-day split has to do with the assumption that it’s better to completely push your body as hard as possible, section by section, but giving each section an entire week to recover.

However, the position that a given body section requires a complete week to recover isn’t set in stone by any means. For example, in a study of male and female athletes, research showed that it took around 48 hours for the men to recover from bench pressing.

Analysis

If that makes you pause, good, because it should. Muscle recovery is a huge topic with many conflicting studies supporting the amount of time needed for muscle recovery. There are additional factors that affect how much recovery time is needed, such as intensity of the workout, nutrition, sleep, age, gender, etc.                                                                

Point being, there really isn’t much to support the idea that training 5 times a week, is particularly effective, or even necessary for most people looking to improve their body compositions.

Then why is it so popular?

On the surface, it makes sense to give your body a lot of time to recover from intense training. There’s a case in the scholarship of subjects reporting that they subjectively felt “recovered” after 6 days, which may contribute to people’s perception that such a long period of recovery is required for optimal performance.

Lately, the 5-day split has been deemed by many as an inefficient way of training. The biggest concern that people have? The idea that by only targeting one muscle group a day, you aren’t maximizing your muscle gains. Research appears to support this claim: a recent (2016) meta-analysis of training frequencies concluded that muscle growth is better encouraged by targeting each muscle group twice a week, not once.

While there is no doubt that exercising 5 days a week will help improve your body composition, it’s not the most time-efficient, and the research doesn’t indicate much additional benefit either, at least as it applies to improving Lean Body Mass.

The 3-Day Training Plan

Philosophy

People that train 3 days a week typically fall into one of two categories. Either they’re way too busy to train more during the week, or they know that training more often would be too difficult to maintain.

Both are valid reasons for using this training frequency. A fitness regimen should certainly challenge you, but if the challenge is too great, you run the risk of setting yourself up for failure.

What can a 3-day training plan look like? Unlike a 5-day plan, there is equal opportunity for doing a split schedule, with a week given for each muscle group to recover, or for a more whole-body approach, where the entire body is exercised at each workout.

Data

The first thing to establish is whether or not 3 days is enough to contribute to meaningful body composition change.

One of the more interesting studies was conducted by the Department of Kinesiology at UCM, which examined the effectiveness of a 3-day workout plan with 2 different protocols – a high frequency and a low frequency.

Despite the different protocols, the researchers found that training 3 days a week was sufficient for Lean Body Mass increases. That’s right: whether you’re training like a madman on each of the three days or working through the exercises at your own pace, a 3-day program is effective at encouraging Lean Body Mass development.

With both forms of training increasing lean body mass by 2% in eight weeks of training alone, it’s clear that 3 day splits are more than frequent enough to cause significant changes in body composition (especially in such a short amount of time).

Analysis

The interesting thing about 3-day splits is their duality. While they are designed to put less stress on your body consistently, they inherently demand more of you. Since you’re training 3 days out of the week instead of 5, you’ll need to give it your all on the days that you do train to make up for the other days where you’re recovering.

That’s not just bro-science, by the way, especially if you choose a whole-body routine in favor of a split. A study by the Department of Health Sciences at CUNY Lehman College found that a 3-day full-body routine actually offers you statistically greater hypertrophy than a 3-day traditional split-body routine.

This lends greater support to the idea that working out each muscle group twice a week instead of once can lead towards efficient Lean Body Mass development. 3 days is enough time to hit all major muscle groups twice, with a third day to use freely to target specific areas.

The 2-Day Training Plan

Philosophy

This might be the most controversial of all the training frequencies we’ve gone over so far. You thought the 5-day split had a bad reputation? Well, the 2-day training plan takes heat from quite a few people in the fitness community.

Why? That’s easy: because people think it doesn’t challenge your body enough to encourage meaningful growth. It completely ditches the traditional convention of having 2-4 rest days to recover (5-day and 3-day respectively), instead opting to give you as many as 5.

So, are they right? Is it crazy to train so infrequently??

Data

Not at all, actually. In fact, for certain people, a 2-day training plan might be the perfect frequency, but there may be a small catch.

For example, a study conducted by McMaster University observed 30 participants over the course of 20 weeks. By the end of the study, they found that the participants that trained only twice per week lost 1% body fat overall and increased their lean body mass by 4%! That’s right, just by training 2 days a week.

Analysis

The most interesting part of that study was how the participant’s body composition improved when you consider the training methods they used. The 2-day whole body workout group was able to cause positive change in their body compositions, as good or even slightly better than the group that did a more traditional 4-day plan.

Why? The data seems to show that it was because they were doing a split-body routine, only targeting one muscle group per day. It goes back to hitting your muscle groups at least twice. While the split group did hit both muscle groups (upper and lower body in this case) twice a week, they did it on separate days, which suggests a slight advantage for not splitting your 2-day whole body into a 4-day split.

However, more to the point: 2-day training plans can absolutely work- but here’s the catch – as long as they’re full-body routines.

Final Thoughts

While reviewing these studies, one thing became clear: these popular training frequencies all work. When implemented properly, each and every one can help you improve your body composition.

So what about our original question: does the frequency of training matter? Generally speaking – and especially for non-athletes – so long as you’re hitting all muscle groups twice a week, the answer appears to be no. Even a 2-day lifting schedule, provided it’s 2-day whole body, has been shown to be effective.

So which should you choose?

If you’re just too busy or know that you’ll get overwhelmed if you take on too much at once, go ahead and dive into that 2-day training plan. If you’re at a more advanced stage in your fitness and you prefer the challenge of lifting more frequently, a 3- or 5-day routine may be preferable.

The important thing to remember is that more important than frequency is consistency. Be consistent with your fitness, and you’ll achieve results. As we’ve shown, things can become a bit murky when trying to tease out the nuances of exactly how many days you need to promote muscle growth. At a certain point, these arguments become academic; just choose a plan that you can realistically meet week after week, and you’ll see results.

As long as you’re exercising regularly and challenging yourself, you’ll be one step closer to a healthier, happier you.

Article by InBody USA blog contributor, Brian Leguizamon.