Resistance training is widely recommended for improving health and building strength, but the common suggestion of two to three sessions per week can feel unrealistic for many busy individuals. This often leads to the question of whether a single weekly weightlifting session can still provide meaningful benefits. It is a common dilemma for people balancing fitness goals with demanding schedules. This article explores the scientific reality of training once a week, examining what can realistically be achieved, how to maximize the limited time, and when a higher frequency becomes necessary.
Defining “Enough”: Goals and Muscle Adaptation
The effectiveness of a single weekly session is entirely relative to an individual’s specific goals. For someone whose aim is the maintenance of existing muscle mass and strength, a single, high-effort weekly workout can often be sufficient, representing the minimum effective dose of resistance training. Research indicates that muscle mass and strength can be preserved for several months with a greatly reduced training frequency, provided the intensity remains high.
However, the requirements for actual muscle growth, known as hypertrophy, are more demanding. Muscle protein synthesis (MPS), the process that drives muscle repair and growth, is significantly elevated for approximately 24 to 36 hours following a challenging weightlifting session. Training a muscle group only once a week leaves a significant period of time where the muscle is not actively stimulated for growth. This limits the total weekly time the muscle is in an anabolic state, constraining maximum muscle gain.
Maximizing the Single Weekly Session
To extract the maximum benefit from a single weekly workout, the session must be structured with maximum efficiency and effort. The primary driver for muscle adaptation is total weekly volume, defined as the number of challenging sets performed per muscle group. A once-per-week schedule requires cramming a significant number of sets into one workout, often totaling 10 to 20 sets per major muscle group for optimal growth stimulus.
The workout must rely heavily on compound movements, which are exercises that involve multiple joints and work several muscle groups simultaneously, such as squats, deadlifts, overhead presses, and rows. Utilizing these multi-joint exercises allows a lifter to provide a broad stimulus to the entire body in a time-efficient manner.
Each working set must be performed with a high level of effort, training close to muscular failure to ensure adequate stimulus. Specifically, this means stopping a set with zero to two repetitions still possible in reserve. While this high-volume, high-intensity approach is effective for stimulating muscle growth, it also generates significant fatigue. The challenge of a single, large session is that the quality of the later sets may diminish as the workout progresses, potentially making them less effective than if the volume were split across multiple days.
When Increased Frequency is Necessary
While a single weekly session can effectively maintain muscle and strength, or produce some initial gains in a beginner, it presents a clear ceiling for advanced progress. If a person’s goal shifts toward significant hypertrophy or maximizing strength gains, an increased training frequency becomes non-negotiable. Distributing the total weekly volume across two or three sessions allows for better recovery between smaller, high-quality workouts.
Advanced lifters, who require greater total weekly volume to continue adapting, often find that attempting to complete all their work in one session leads to excessive fatigue and diminished performance on later exercises. Splitting the volume over multiple days, such as training a muscle group twice a week, has been shown to offer a slight advantage for hypertrophy compared to once a week when total volume is matched.
This higher frequency is also necessary for individuals training for specific athletic events or sports performance, where the neuromuscular system requires more frequent practice to enhance skill and movement patterns. Finally, those pursuing rapid body composition changes, such as significant fat loss while building muscle, benefit from the increased energy expenditure and sustained MPS that multiple weekly sessions provide.