Dieting can bring about lowered energy levels which can impact workout performance and recovery. Does this mean we should cut back on the amount of work we do in the gym or simply suck it up and push through? A new systematic review looks into this age-old debate.


When dieting, it’s common to notice a slight deficit in your levels of energy. This is impacted directly of course by how aggressive you are dieting, meaning, how much of a calorie deficit you enter and maintain.

With lower energy levels can come impaired performance in the gym, as well as hindered recovery from session to session.

Because of this, many lifters decide to cut training volume (how many sets and reps they perform) in order to make their program more sustainable during the period of reduced energy.

The question is and always has been, is this advisable?

Currently, we don’t have studies that actually compare body composition outcomes in multiple groups undergoing manipulations in training volume within the context of an intentional energy deficit.

As a result, this paper sought to address this question by leaning on indirect research.

They did a systematic literature search to gather studies investigating changes in lean mass among healthy, drug-free lifters consuming a hypocaloric (daily energy deficit ≥200kcal) and high-protein (daily protein intake ≥2.0g/kg of fat-free mass) diet for at least four weeks in duration, with the intention of determining if differing levels of training volume tend to lead to better or worse lean mass changes.

They were also interested in determining if relative changes in volume (that is, increasing or decreasing volume throughout a program) impacted lean mass changes.

After screening 2,791 studies and applying exclusion criteria, the researchers ended up with a total of 15 studies, including 8 case studies.


The researchers concluded that during energy restriction:

  1. Females on high-volume programs tend to retain more lean mass than males.
  2. There is insufficient evidence to confidently conclude that high-volume programs spare more lean mass than low-volume programs (although the data seem to lean in that direction, particularly for female lifters).
  3. Actively reducing training volume may lead to greater losses of lean mass.
  4. Actively increasing training volume may lead to better lean mass retention.

Interpretation & Takeaways

Because of the manner in which this review was performed, combining multiple studies that weren’t really looking into the relationship between energy deficits and volume changes, this review should be taken with a grain of salt.

At this point in time, we simply don’t have the evidence to confidently determine if lean mass retention is optimally promoted by high-volume or low-volume programs, or to determine if lean mass retention is optimally promoted by increasing, decreasing, or preserving volume, during periods of intensive energy restriction.

Based on evidence related to the effects of glycogen depletion on exercise performance, and the effects of volume reduction on the maintenance of resistance training adaptations, it makes sense to generally lean in favor of sacrificing some volume to accommodate the demands of aggressive energy restriction.

Ultimately, one should lean on their experience and individualize their approach as needed; some lifters might struggle to perform well and recover from high-volume programs while cutting, whereas others might have entirely different experiences.