Training adaptations associated with an 8-week instability resistance training program with recreationally active...

Area of Science:

• Exercise Physiology
• Biomechanics
• Sports Science

Background:

• Instability devices are popular for training, but their effectiveness is debated.
• Resistance training is crucial for improving physical performance.
• Understanding the physiological and performance adaptations to different training modalities is essential.

Purpose of the Study:

• To compare the effectiveness of stable versus unstable resistance training.
• To determine differences in physiological and performance outcomes after 8 weeks of training.
• To investigate the impact of instability on strength, neuromuscular efficiency, and balance.

Main Methods:

• Eighteen untrained subjects (10 men, 8 women) trained 3 days/week for 8 weeks.
• Training was conducted under either stable or unstable conditions.
• Pre- and post-training assessments included isometric chest press force, electromyography, throwing distance, balance, countermovement jump (CMJ), drop jump (DJ), and wobble board tests.

Main Results:

• No significant differences were found between training groups for most measures.
• A trend indicated greater improvement in the stable-to-unstable chest press force ratio for the unstable group (24.8% vs. 10.8%).
• Significant improvements were observed overall in maximum voluntary isometric contraction (MVIC) force, bench press, squat, CMJ, DJ, and balance measures, regardless of training condition.

Conclusions:

• Instability resistance training can enhance strength and balance in untrained individuals, similar to stable training with heavier loads.
• Despite lower reported forces, unstable training appears effective for improving key physical performance indicators.
• Further research may explore optimal protocols for instability training to maximize specific adaptations.