Acute cardiovascular exercise diminishes the consolidation of a complex whole-body task in young adults.

Both CVE groups showed reduced offline learning at the 24-hour retention test compared to the resting group, indicating a large effect.

• Weighted mean offline change for CVE groups: 2.9%; REST group: 12.5%
• 41 neurotypical young adults participated in the pre-registered experiment
• Participants were randomized into three groups: high-intensity interval CVE, moderate-intensity interval CVE, or rest immediately after encoding
• Effect size was described as 'large'

The negative effect of post-encoding CVE on motor memory consolidation was no longer present at the 7-day retention test.

• Retention tests were conducted at 24 hours and 7 days after encoding
• Relative offline changes were calculated from the end of encoding to each retention test
• The attenuation of consolidation observed at 24 hours resolved by the 7-day follow-up

The negative effect of post-encoding CVE on early consolidation was unaffected by several moderating variables.

• Variables examined included biological sex, cardiorespiratory fitness, subjective sleep quality, and post-exercise lactate levels
• None of these variables moderated the negative effect of CVE on consolidation
• This suggests the attenuation effect was consistent across participants regardless of these characteristics

The CVE protocols used were high-intensity interval training (90/60% Wmax) and moderate-intensity interval training (45/25% Wmax), both previously shown to enhance consolidation in fine-motor tasks.

• High-intensity group exercised at 90/60% Wmax
• Moderate-intensity group exercised at 45/25% Wmax
• These specific protocols had prior evidence of enhancing consolidation in fine-motor paradigms
• Exercise was performed immediately after the encoding phase of a balance task

The authors propose catecholamine-driven reduction of frontal brain processes and interference between overlapping neural circuits as possible mechanisms for the observed attenuation of consolidation.

• Catecholamine release from CVE may reduce frontal brain processes involved in motor memory consolidation
• Neural circuit overlap between the complex whole-body motor task and CVE may cause interference
• These mechanisms are discussed as distinct from those relevant in fine-motor task paradigms
• The authors note this challenges assumptions derived from fine-motor paradigms

The study used a complex balance task to examine gross-motor learning, an area where data on the effects of post-encoding CVE are scarce.

• Most prior evidence for post-encoding CVE enhancing motor memory consolidation comes from fine-motor tasks
• The balance task was used as a model of gross-motor (complex whole-body) skill learning
• The experiment was pre-registered
• Sample consisted of 41 neurotypical young adults