How many workouts bodybuilders can skip (without reducing their progression)?

Bodybuilders who skip the occasional workout – because they lack the time or inclination – make just as much progress as bodybuilders who never miss a session. But athletes who skip more than 20 % of their training sessions are definitely jeopardizing their progression, according to a study that sports scientists at the University of Brasilia.

The Brazilians did an experiment with 90 male students, who at the start of the study had never touched weights. The researchers asked all of the students to train twice a week in a gym. The experiment lasted 11 weeks.

The workouts consisted of five basic exercises: leg press, leg curls, bench press, lat pull-downs and old-fashioned sit-ups. The students trained using a weight with which they could manage 8-12 reps, and rested for 90-120 seconds between sets.

Low, mid & high
Not all students attended the gym sessions faithfully. The researchers labelled 21 of the students “Low attendance”. On average these students missed a quarter of the workouts.

The Intermediate-attendance group were slightly more dedicated. They only missed an average of 15 percent of the training sessions.

The High-attendance group only missed 5 percent of the training sessions.

Leg strength
The researchers discovered that all groups developed the same amount of strength in their leg muscles.

Bench press
But missing training sessions did influence the amount of kilograms the students were able to lift when doing bench presses. The weight with which they could just manage 1 rep  increased by more in the Intermediate and High-attendance groups than in the Low-attendance group.

“We suggest that, during exercise prescription for young men, it is recommended to establish a minimum of 80 percent of training attendance to get optimal upper body strength gains”, the Brazilians conclude. “This information may be important for coaches and athletes during the design and execution of an RT program and for researches in the design of research protocols.”

Effects of training attendance on muscle strength of young men after 11 weeks of resistance training.

Training attendance is an important variable for attaining optimal results after a resistance training (RT) program, however, the association of attendance with the gains of muscle strength is not well defined. Therefore, the purpose of the present study is to verify if attendance would affect muscle strength gains in healthy young males.

Ninety two young males with no previous RT experience volunteered to participate in the study. RT was performed 2 days a week for 11 weeks. One repetition maximum (1RM) in the bench press and knee extensors peak torque (PT) were measured before and after the training period. After the training period, a two step cluster analysis was used to classify the participants in accordance to training attendance, resulting in three groups, defined as high (92 to 100%), intermediate (80 to 91%) and low (60 to 79%) training attendance.

According to the results, there were no significant correlations between strength gains and training attendance, however, when attendance groups were compared, the low training attendance group showed lower increases in 1RM bench press (8.8%) than the other two groups (17.6% and 18.0% for high and intermediate attendance, respectively).

Although there is not a direct correlation between training attendance and muscle strength gains, it is suggested that a minimum attendance of 80% is necessary to ensure optimal gains in upper body strength.