The training split I’ve been using for the past six months is a full-body routine, five days a week. While this might sound excessive to some, I find it incredibly effective. Many people advocate for body part splits, focusing on one or two muscle groups per day and allowing a full week of rest for muscle growth. Although this method can work, there are arguably more efficient training approaches. Push-pull-leg splits, for example, hit each muscle twice a week, which scientific literature suggests is beneficial for muscle growth. Upper-lower splits are another solid option. While full body workouts are common, they are often seen as beginner routines performed two or three times a week. This is what makes a five-day full body split so unique. Hitting every muscle every day might seem counterintuitive, but it’s not.
I was introduced to this training style three years ago in an interview with Menno Henselmans. He explained that optimal training frequency varies between beginners and advanced trainees. Research indicates that beginners don’t benefit from training a muscle group more than once a week. However, as you become more advanced, the period of elevated muscle protein balance decreases. After lifting weights, muscle protein synthesis increases, and the muscle becomes more sensitive to amino acids, which promotes muscle growth. This response remains elevated for about two days in new lifters but returns to baseline after just 12 hours in experienced trainees.
The theory suggests that for well-trained individuals, more frequent muscle stimulation leads to more spikes in muscle protein synthesis and greater muscle growth. The question remains whether these frequent spikes actually result in more muscle growth over time. This is a controversial topic. Some skeptics argue that studies often measure mixed muscle protein synthesis, which isn’t as relevant for building contractile muscle tissue as myofibrillar muscle protein synthesis. A 2014 study even challenged the correlation between acute protein synthesis and hypertrophy. However, other research supports the idea that protein synthesis does predict hypertrophy, a view I personally believe is better supported by the literature.
The key question is whether this high-frequency training approach results in noticeable muscle growth. This is where things get interesting. In 2012, Norwegian sport scientists conducted a secret frequency study, known as the infamous Norwegian Frequency Project. Designed for their national powerlifting team, the results were never fully published. The study compared a group training full-body three times a week to a group training six times a week, keeping weekly volume constant. After 15 weeks, the six-day group saw nearly double the strength and size gains, increasing their lifts by 10% compared to 5% for the three-day group. However, since this data wasn’t peer-reviewed, skepticism is warranted.
A later study attempted to replicate the Norwegian project with early intermediate lifters over six weeks. Unsurprisingly, they found similar strength and size gains between the three-day and six-day groups. This suggests that both frequencies can be effective, but the benefits of higher frequencies may be more pronounced in experienced lifters. An important consideration is that these studies equate weekly volumes between groups, which isn’t realistic. Higher training frequencies often lead to higher volumes. This has led experts to argue that these studies overlook the primary benefit of high-frequency training: accumulating more high-quality volume.
When training with Eric Helms, he emphasized the main advantage of high-frequency full-body training: spreading out weekly volume to improve the quality of each set. This allows for better volume distribution with less fatigue throughout the week. Essentially, training splits become a matter of organizing volume, intensity, and recovery.
The current scientific consensus suggests 10 to 20 working sets per week per muscle. However, the per-workout volume also matters. Data suggests a per-workout ceiling of five to ten sets per muscle. Beyond this, additional sets risk becoming wasted sets or junk volume. High-frequency training, by distributing volume across more workouts, reduces the likelihood of wasted sets.
Full-body training also offers an intensity advantage. While initially I expected fatigue from consecutive training days, I found the opposite to be true. Focusing on one exercise per muscle allows for greater focus and attention. The lower per-workout volume compared to other splits leads to faster recovery. For instance, on my lower body day, I only perform three sets of leg press and four sets of calf raises. This allows for better execution compared to doing them after squats and lunges on a dedicated leg day.
Recovery is the biggest concern for most people. It seems impossible to recover with only 24 hours between workouts. However, it’s not as difficult as it sounds. Training chest every day doesn’t mean performing a full chest workout each day. It’s more like splitting a typical chest workout across several days. Additionally, the repeated bout effect kicks in after a few weeks, allowing the body to adapt and recover faster. This often eliminates soreness, which can impede performance. Therefore, a high-frequency split can actually improve recovery, assuming volume and intensity are managed appropriately, particularly in the beginning.
While high-frequency training seems advantageous, there are some considerations. Due to the shorter recovery period, it’s crucial to stop short of failure during the initial weeks, aiming for an RPE of 7-8 instead of 8-9. As the body adapts, training closer to failure can be resumed. Training while sore might be necessary for the first week or two, which highlights the importance of a thorough warm-up. This soreness typically disappears after the initial weeks.
For me, full-body five days a week is currently the best split. After years of push-pull-leg and upper-lower splits, this routine provides the motivation I need for continued progress. However, it’s not universally the best for everyone.
