In one sentence
When total practice time was matched, a 4-week, three-sessions-a-week balance programme and a 6-week, twice-weekly programme both improved adolescent postural tests — and the “spread it out” schedule was not the clear winner.
What the researchers did
Wissmann, El Houssaini, Hill, and Muehlbauer randomly assigned 25 healthy male adolescents (mean age about 15.8 years) to one of two equal-volume balance-training plans:
- Massed: 4 weeks, 3 sessions per week, 30 minutes each (sessions ~48 hours apart).
- Distributed: 6 weeks, 2 sessions per week, same session length (sessions ~72 hours apart).
Each session used the same five exercises (pad stance, wobble board, weight shifts, vertical and horizontal jump-landings), progressed by closing the eyes and lengthening holds. A sport scientist who did not know group assignment tested one-legged stance (eyes closed, firm and foam) and the Y Balance Test (reach distances, including a composite score) before and after training. Power analysis had targeted about 22 participants; 12 and 13 completed the two arms. There was no no-training control group.
What they found
- Static and dynamic balance improved from pre- to post-test in both groups on the main stance and reach measures (large main effects of time).
- Most outcomes showed no group × time interaction — scheduling did not clearly change the size of the gain.
- One exception: posterolateral reach showed an interaction (p = 0.041, partial η² 0.17), with a medium pretest–posttest effect in the massed group versus a trivial effect in the distributed group.
- The authors’ pre-study hypothesis that distributed practice would win was not supported for this motor task and these gaps (48 vs 72 hours).
What this means for learners and educators
- Spacing is not a magic multiplier when sessions already have days between them and the skill is postural control. Academic memory research still favours spacing over cramming in one sitting; this trial is about week-scale calendars for a motor outcome.
- Coaches can pick the calendar that students will actually attend if total volume is similar.
- Do not import this result into exam revision: a vocabulary list crammed tonight is not the same task as standing on a foam pad with eyes closed.
Limitations and what we don't know yet
n = 25, males only, sports-club adolescents, no control group (practice effects on the tests themselves are possible). Only one of several reach directions favoured massed practice. Retention after the programme ended was not reported. Findings may not apply to cognitive study, to girls, or to spacing of minutes versus hours inside a single day.
FAQ
Does this mean cramming works as well as spaced study?
No. Both groups already spaced sessions by at least two days. That is not overnight cramming before a written exam.
Why mention this on a learning-science site?
Distributed versus massed practice is a core idea here. Motor-skill trials sometimes fail to copy the classroom spacing story — worth knowing so we do not over-generalise.
What should a student do with this?
Keep spacing for facts and concepts. For physical skills, match volume and pick a timetable you can keep.