Acute Effects of Aerobic Exercise Intensity on Lower-Limb Muscle Strength and Power in Youth Gymnasts

Intensity-Dependent Acute Effects of Aerobic Exercise on Lower-Limb Muscle Strength and Power in Elite Male Youth Gymnasts: A Randomized Crossover Trial

This study investigates the acute effects of different aerobic exercise intensities on lower-limb muscle strength and power in elite male youth gymnasts. Aerobic exercise is commonly included in gymnastics training to improve fitness and recovery, but performing aerobic exercise immediately before strength- and power-demanding activities may temporarily influence neuromuscular performance.

Eighteen nationally certified male youth gymnasts aged 15 to 18 years participated in a randomized crossover trial. Each participant completed three treadmill-based aerobic exercise conditions on separate days: high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and low-intensity steady-state exercise (LSD). Muscle strength and power were assessed before and 15 minutes after each exercise condition using validated force-platform tests, including vertical jumps and isometric strength assessment.

The results of this study will help clarify how aerobic exercise intensity influences short-term strength and power performance in youth gymnasts and may inform evidence-based decisions on training sequencing and warm-up strategies in gymnastics practice.

This study is a randomized crossover trial designed to examine the acute, intensity-dependent effects of aerobic exercise on lower-limb muscle strength, power, and power endurance in elite male youth gymnasts. In high-performance gymnastics training, aerobic conditioning is frequently combined with strength and technical training within the same day. However, the immediate neuromuscular effects of aerobic exercise performed at different intensities remain unclear in youth power-oriented athletes.

Eighteen elite male youth gymnasts (aged 15-18 years), free from musculoskeletal injury and with national-level competitive experience, were recruited. After baseline assessments, each participant completed three aerobic exercise conditions in a randomized order, with a minimum washout period of 72 hours between sessions. The exercise conditions included high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and low-intensity steady-state exercise (LSD), all performed on a motorized treadmill. Exercise intensity was individually prescribed based on maximal heart rate and maximal aerobic speed determined during baseline testing.

Lower-limb muscle strength and power were assessed before and 15 minutes after each exercise condition using force-platform-based tests, including countermovement jump, squat jump, drop jump, repeated countermovement jumps, and isometric mid-thigh pull. Subjective fatigue and muscle discomfort were also recorded using standardized rating scales.

The primary objective of the study is to compare the acute changes in explosive power, power endurance, and maximal strength following aerobic exercise performed at different intensities. This study focuses on short-term neuromuscular responses rather than long-term training adaptations. Findings from this trial are expected to provide practical evidence for optimizing the sequencing of aerobic and strength-power training in elite youth gymnastics.

Inclusion Criteria:

• Male youth gymnasts aged 15 to 18 years.
• Nationally certified or competitively trained gymnasts with regular training experience.
• Free from musculoskeletal injury within the past six months.
• Able to complete treadmill running and strength and power testing.
• Written informed consent provided by participants and their legal guardians.

Exclusion Criteria:

• Presence of acute or chronic musculoskeletal injury.
• History of cardiovascular, respiratory, or neurological disorders.
• Use of medications or supplements that could affect neuromuscular performance.
• Inability to complete all exercise conditions or testing procedures.