Comparison of Muscle Activation and Fatigue Levels in Barbell Squat Exercise Performed with Machine and Free Weights

Abstract

The squat exercise is a fundamental movement in resistance training that enhances athletic performance, supports joint stability, and increases bone density. The execution of squats using either free weights or machines can influence muscle activation and fatigue levels. This study aimed to compare the acute effects of barbell squat exercises performed with free weights and the Smith machine on muscle activation, perceived exertion, and jump performance. Seventeen university students (age: 23.0 ± 2.8 years) with resistance training experience participated in this randomized crossover study. Participants performed barbell squats at 70% of their one-repetition maximum (1RM) using two different protocols: free weight squats and Smith machine squats (5 sets of 8 repetitions, with 3-minute rest intervals between sets). Findings indicated that muscle activation in the vastus lateralis was significantly higher in the Smith machine condition (p < 0.05), while no significant differences were observed in perceived exertion (RPE) and countermovement jump (CMJ) performance between the two squat modalities (p > 0.05). Additionally, both squat techniques resulted in similar decreases in CMJ performance after the exercise session. These results suggest that while the Smith machine increases muscle activation compared to free weights, the overall performance outcomes and perceived exertion levels are comparable between the two squat methods. Coaches and athletes may incorporate both methods into their training programs based on individual goals and preferences.

Keywords

• Jump performance
• muscle activation
• perceived fatigue
• resistance training
• smith machine

Makine ve Serbest Ağırlıkla Uygulanan Halter Squat Egzersizinde Kas Aktivasyonu ve Yorgunluk Düzeylerinin Karşılaştırılması

Abstract

Squat egzersizi, direnç antrenmanlarında temel bir hareket olup, atletik performansı artırmanın yanı sıra eklem stabilitesini destekler ve kemik yoğunluğunu yükseltir. Squat egzersizlerinin serbest ağırlıklar veya makinelerle uygulanması, kas aktivasyonu ve yorgunluk düzeylerini etkileyebilir. Bu çalışmanın amacı, serbest ağırlıkla ve Smith makinesi ile uygulanan halter squat egzersizlerinin akut etkilerini kas aktivasyonu, algılanan yotgunluk ve sıçrama performansı açısından karşılaştırmaktır. Direnç antrenmanı geçmişi olan on yedi üniversite öğrencisi (yaş: 23,0 ± 2,8 yıl) randomize çapraz desenli tasarım ile araştırmaya dahil edilmiştir. Katılımcılar, %70 1 tekrar maksimum (1RM) yükle, iki farklı protokol doğrultusunda halter squat uygulamıştır: serbest ağırlıkla squat ve Smith makinesiyle squat (5 set x 8 tekrar, setler arası 3 dakikalık dinlenme). Bulgular, vastus lateralis kasında kas aktivasyonunun Smith makinesi protokolünde anlamlı olarak daha yüksek olduğunu göstermiştir (p < 0.05). Ancak algılanan yorgunluk (RPE) ve sıçrama performansı (CMJ) açısından iki squat yöntemi arasında anlamlı bir fark gözlenmemiştir (p > 0.05). Ayrıca, her iki protokol de egzersiz sonrası CMJ performansında benzer düzeyde azalmaya yol açmıştır. Bu sonuçlar, Smith makinesinin serbest ağırlıklara kıyasla kas aktivasyonunu artırmasına rağmen, genel performans çıktıları ve algılanan yorgunluk düzeylerinin iki yöntem arasında benzer olduğunu göstermektedir. Antrenörler ve sporcular, bireysel antrenman hedefleri ve tercihlere göre her iki yöntemi de programlarına dâhil edebilir.

Keywords

• Sıçrama performansı
• Kas aktivasyonu
• Algılanan yorgunluk
• Direnç antrenmanı
• Smith makinesi

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