How to grow muscle in just 30 minutes twice a week

By: May 22, 2025

What’s (by far) the biggest excuse people use for not resistance training?

 

TIME!

 

In fact just 28% of the US population regularly engages in resistance training twice weekly. 

 

But is that actually even a problem?

 

We wrote a blog last year about how being a weekend warrior can still offer dramatic benefits to lower your risk of dying.  There is also compelling data on using short ‘exercise snacks’ to promote more activity and again increase your longevity.

 

Prior research has showed that doing just a single set of resistance training can change your muscles positively but it’s typically thought that you must do one set to failure, meaning you can not lift the weight any further.

 

A very recent paper just came out looking at a single set of exercise done to failure or using what is called the repetitions in reserve method where you terminate your set when you feel you have 2 repetitions left.  Specifically they were looking to see if one method was superior to the other in terms of improving muscle cross sectional area, strength and power measures.

 

One of the interesting parts to this study is that it was completed on young healthy individuals (mostly men) that were already highly trained, meaning they had to do resistance training at least 3 times weekly for a full year to qualify for the study.

 

Often when studies looking at a singular factor like this are completed they use untrained people because these folks show much higher positive changes to any intervention.

 

The study took 50 university aged people, and randomized them to either a train to failure group or a 2 reps in reserve group.  They then put them through a general upper and lower body resistance training program just two times per week for 8 consecutive weeks.

 

The participants would come in and work out supervised by the research team to ensure proper performance of the exercises.

 

One key to the program is that it ONLY TOOK 30 MINUTES EACH SESSION.  They performed each exercise set for 8-12 repetitions with 2 minutes of rest in between, so realistically the amount they lifted was quite minimal.

 

So what were the changes?

 

 

As you can see above both groups did surprisingly well.

 

In general you can summarize the changes as follows:

  • Both interventions (train to failure and 2 reps in reserve) promoted small to medium increases in muscle thickness but it slightly favoured the train to failure group.
  • There was little to no different between groups for strength changes.
  • The failure group had a slightly greater power improvement
  • There was no difference in improvements for muscular endurance.

 

Pretty cool.

 

Essentially these results show you can have appreciable muscle gains achieved with relatively low set volumes and you do NOT need to work to failure…….remember just 30 minutes twice weekly for 8 weeks is all that they had participants do.

 

And these results were on already trained individuals.  In fact, these folks had to do way less training then they typically do to participate in the study yet they still showed improvements!  These folks actually enhanced their fitness by training less!

 

This year will be insanely busy for me and my family.  I’d love to use excuses for not getting to the gym enough.

 

This paper shows with just 30 minutes of training twice weekly I can make important gains so whether I like it or not, time can’t be a factor for not training

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