# Training: 1x/week or 3x/week? Which is better? URL: https://sciencebased.news/training-frequency/ Published: 2026-10-19 Updated: 2026-10-21 Claim: As long as you do the same weekly sets, it doesn't matter if you train a muscle once, twice or three times a week. Grade: Promising What to do: - Pick a weekly number of hard sets for each muscle. Around 10 is a common target; in a 67-study analysis even 4 a week grew muscle, and more sets kept adding. - Split those sets over 1, 2 or 3 days, whatever fits your week. In 16 trials, the split made no difference to growth. - Make every set hard. In 11 of the 16 trials, every working set went to the point where one more clean rep was impossible. - Safety: if one long session leaves a joint sore or your form falls apart late in it, spread the same sets over more days. With heart disease, ask your doctor first. - Not proven: that it holds past 12 weeks, above 3 sessions a week or at very high volumes. For lifting heavier, more frequent practice may help. # Training: 1x/week or 3x/week? Which is better? *Evidence check, October 19, 2026. Updated October 21, 2026.* > **The claim:** As long as you do the same weekly sets, it doesn't matter if you train a muscle once, twice or three times a week. > > **Our grade: Promising.** In 16 randomized trials with 380 people, muscle grew the same whether its weekly sets came in one, two or three sessions, and earlier reviews agree. The trials were small and short (6 to 12 weeks), and the new review is not yet peer reviewed. ![Leo, 26, sits on a gym bench writing in a small notebook. Beside him a weekly planner shows one workout, on Monday, in the 1x row and three, on Monday, Wednesday and Friday, in the 3x row, under the words 1x OR 3x A WEEK?](https://sciencebased.news/images/training-frequency-hero.jpg) Leo is 26. Between work and a long commute he gets to the gym twice a week, so his legs get one session. He has heard that each muscle needs hitting at least twice a week. So is his one leg day a waste? A review posted on October 9 pooled every trial that tested this question fairly: 16 of them, with 380 people [3]. Its answer is good news for anyone with a busy week. ## Where the claim came from Two of the most-watched voices in lifting have spoken to this. In 2018, Jeff Nippard posted "Training Volume and Frequency", a video now past 800,000 views [1]. His words: "two times a week frequencies, so that's two times per week per body part, tend to be better than hitting every body part only one time per week," even "assuming that volume is matched." Later in it: "we do know that two times per week is marginally better." That was exactly what the best review at the time concluded. In 2016 it found that, at equal volume, twice a week beat once [4]. It had few studies to go on, and its authors could not test every comparison they wanted. In 2022, the exercise scientist Andy Galpin told Andrew Huberman the opposite [2]. "If you want to take five days or six days in between each muscle group, you can do that. In fact, if you look at the research, it's going to show that frequency is not that important ... as long as you get to the same total volume." For him, "the total driver of hypertrophy is volume." Hypertrophy means muscle growth. Volume here means the number of hard sets for a muscle each week. So who is right? Settling it takes trials that hold the weekly sets exactly equal, and enough of them to pool. ## 16 trials: the split did not matter The new review, by Anthony Boutagy and Mark McKean of the University of the Sunshine Coast in Australia, took only trials that held weekly sets equal [3]. One group might do 9 sets for the thighs in one session; the other, 3 sets in each of three sessions. Same loads, same reps, same total. Only the split differed. Sixteen randomized trials fit, with 380 people. They included trained and untrained men, older women, women after menopause and mixed groups. Each ran 6 to 12 weeks, and each measured muscle size, mostly with ultrasound. The pooled difference was −0.02 on the standard effect-size scale, where 0.2 counts as small [3]. That is zero. The trials also agreed with each other: the spread between them was no more than chance would give. That leaves a fair doubt. In one long session, the last sets are done tired. Can they count as much as fresh sets on another day? The trials with the biggest single sessions answer it. In 9 of them, the once-a-week group did 9 to 18 sets for one muscle in a single session, and none found that more sessions grew more muscle [3]. The long session did the job. ![Forest plot of 16 trials. Each row is one trial, with a square for its result and a line for its 95% confidence range, grouped as once against twice, once against three times and twice against three times a week. Every line crosses zero. The three group averages are +0.07, −0.12 and −0.01, and the overall average is −0.02, a diamond sitting on zero.](https://sciencebased.news/images/training-frequency-chart.png) *Redrawn from Figure 2 of Boutagy and McKean, 2026 [3]. Left of zero favors more sessions; right favors fewer.* Once against twice a week: 5 trials, 112 people, a difference of +0.07, slightly toward once [3]. Once against three times: 6 trials, 106 people, −0.12, slightly toward three. Twice against three times: 5 trials, 162 people, −0.01. None of the three was different from zero. The two trials in older women and women after menopause, with 85 people, compared two and three days a week. They found +0.00 and −0.21: no clear difference [3]. The result held when the reviewers dropped the trials at higher risk of bias (−0.01), kept only direct measures of muscle (−0.02), or split trained from untrained people (+0.03 and −0.08) [3]. The same answer came from two earlier reviews. In 2019, the lead author of the 2016 review redid it with 25 studies and found "strong evidence that resistance training frequency does not significantly or meaningfully impact muscle hypertrophy when volume is equated" [5]. The American College of Sports Medicine's 2026 guidelines, built from 137 reviews, reached the same view: at equal volume, training a muscle 1 day a week or more than 5 made no difference to growth [7]. What did matter was the number of sets. A 2026 analysis of 67 studies with 2,058 people found that muscle kept growing as weekly sets went up, by smaller steps each time [6]. About 4 hard sets a week was the smallest dose with growth large enough to detect. In that analysis, too, frequency had no clear effect on growth. So back to Leo. His one leg day is not a waste. If it holds the same hard sets his legs would get over two days, the trials say his legs grow just as well. ## What we don't know The trials were small. Together they could rule out a large difference but not a small one; the reviewers say about 785 people would be needed to settle that, against 380 in the pool [3]. Most measured muscle thickness at one or a few spots with ultrasound. Only one trial used MRI, which sees the whole muscle. In the largest comparison of the two methods, thickness captured under a third of the growth MRI found [3]. Effort was not always matched. Equal sets did not mean equal work: in one trial, the three-a-week group lifted 58% to 76% more total weight in the same number of sets [3]. No trial ran past 12 weeks, none went above three sessions a week, and very high weekly volumes were not tested [3]. One trial outside the review, at five sessions a week against one, with 15 sets in the single session, did favor the higher frequency [3]. The review itself has limits. It has not been peer reviewed. One author did most of the data work, an AI tool helped screen papers and pull data from four trials (checked by the authors), and the plan was not registered in advance [3]. The authors report no funding and no conflicts. ## Our grade | Claim | Evidence | Grade | |---|---|---| | With the same weekly sets, training a muscle once a week grows it as well as two or three times | 16 randomized trials, 380 people, 6 to 12 weeks; earlier reviews agree | Promising | | More weekly sets bring more growth | 67 studies, 2,058 people | Solid | | Twice a week beats once at the same weekly sets | A 2016 review said yes; the 2019 review, the new one and ACSM found no difference | Debunked | | The same holds over a year or more | No trial ran past 12 weeks | Unproven | | More frequent sessions build more strength | Reviews disagree once sets are equal | Weak | | Overall: at the same weekly sets, how you split them doesn't change muscle growth | Many small trials agree | Promising | The case for the other side: the review could miss a small edge for more sessions. Most trials measured thickness at a few spots, and whole-muscle growth could differ. Strength may be different. The 67-study analysis found that more frequent sessions helped strength [6], while a 2018 review found that the edge disappeared once weekly sets were equal [8]. Galpin's advice for strength is "Two is a good number, three is great" [2]. What would change the grade: a trial that runs six months or more, measures the whole muscle with MRI, and matches effort, not only sets. ## What this means for you - Count your weekly hard sets for each muscle. That number matters more than the schedule [3, 6]. - About 10 sets per muscle per week is a common target. ACSM found 10 or more grew more muscle than fewer [7], and Galpin calls it "kind of the minimum threshold" [2]. Even 4 grew muscle in the 67-study analysis, and more kept adding, in smaller steps [6]. - Split them however fits your life: one long session, two medium ones or three short ones [3]. - Make the sets hard. In 11 of the 16 trials, every working set ended when one more clean rep was impossible [3]. - If one session would be huge, split it. A set late in a long session may be worse than the same set done fresh, and the reviewers name very high volumes as the case for more sessions [3]. - If lifting heavier is the goal, training a lift two or three times a week is a reasonable choice [2, 6]. - If you are over 60, two and three days a week did equally well in older women [3]. A muscle you have built is easier to keep: studies of reduced training kept it on very little, though older adults needed more than younger ones [3]. ## What's next The reviewers ask for longer trials that measure the whole muscle with MRI, track how close each set is to failure, and test more than three sessions a week [3]. To get more from the sets you do, see [how much protein you need](/protein-target/) and [what creatine adds to lifting](/creatine/). If you take a GLP-1 drug, lifting matters even more; see [keeping muscle on GLP-1 drugs](/glp1-muscle-loss/). ## Sources 1. Nippard J. Training Volume and Frequency | Chapter 2: The Fundamentals Series. YouTube video, June 30, 2018. Quotes from the video's transcript. https://www.youtube.com/watch?v=7S0NjKYlJ7I 2. Huberman A, Galpin A. Dr. Andy Galpin: How to Build Strength, Muscle Size & Endurance. Huberman Lab podcast, March 28, 2022. Quotes from the episode's transcript. https://www.youtube.com/watch?v=IAnhFUUCq6c 3. Boutagy AG, McKean M. Resistance Training Frequency and Muscle Hypertrophy: A Systematic Review and Meta-Analysis of Volume-Equated Trials. *medRxiv* preprint, October 9, 2026, not peer reviewed. 16 randomized trials, 380 participants, 6 to 12 weeks, weekly sets equal between groups. No funding; no conflicts reported. [doi:10.64898/2026.10.07.26365015](https://doi.org/10.64898/2026.10.07.26365015) 4. Schoenfeld BJ, Ogborn D, Krieger JW. Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis. *Sports Medicine*, 2016. Mostly studies without equal weekly volume. Read as abstract only. [doi:10.1007/s40279-016-0543-8](https://doi.org/10.1007/s40279-016-0543-8) 5. Schoenfeld BJ, Grgic J, Krieger J. How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency. *Journal of Sports Sciences*, 2019. 25 studies. Read as abstract only. [doi:10.1080/02640414.2018.1555906](https://doi.org/10.1080/02640414.2018.1555906) 6. Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC. The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains. *Sports Medicine*, 2026. 67 studies, 2,058 participants (79% men, average age 25). [doi:10.1007/s40279-025-02344-w](https://doi.org/10.1007/s40279-025-02344-w) 7. Currier BS, et al. American College of Sports Medicine Position Stand. Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults: An Overview of Reviews. *Medicine & Science in Sports & Exercise*, 2026. 137 systematic reviews. [doi:10.1249/MSS.0000000000003897](https://doi.org/10.1249/MSS.0000000000003897) 8. Grgic J, Schoenfeld BJ, Davies TB, Lazinica B, Krieger JW, Pedisic Z. Effect of Resistance Training Frequency on Gains in Muscular Strength: A Systematic Review and Meta-Analysis. *Sports Medicine*, 2018. Read as abstract only. [doi:10.1007/s40279-018-0872-x](https://doi.org/10.1007/s40279-018-0872-x)