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Acute Effects of Variable-Resistance and Free-Weight Bench Pull Exercise in Resistance-Trained Men

22 de setembro de 2026 atualizado por: Zongwei Chen, South China Normal University

Acute Comparison of High-Load Variable-Resistance and Free-Weight Bench Pulls: A Randomized Crossover Study of Exercise Responses and Residual Effects

This study used a randomized, counterbalanced crossover design to compare high-load chain-based variable-resistance (VR) and free-weight (FW) bench pulls. Resistance-trained men completed two experimental sessions separated by 72 hours, with the order of the VR and FW conditions randomized.

Before each experimental condition, participants completed a standardized general and bench pull-specific warm-up followed by a 10-minute rest period. In each session, participants performed one set of three bench pull repetitions at approximately 85% of their free-weight one-repetition maximum (1RM). In the VR condition, the external resistance was provided by a combination of barbell load and chains, with chains contributing approximately 20% of the effective mean total load. In the FW condition, the external resistance was provided entirely by the barbell.

Following the high-load bench pull, participants rested for 3 minutes and then completed three standardized sets of free-weight bench pulls at approximately 75% 1RM, with 3-minute rest intervals between sets. Each subsequent set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion.

Direct exercise responses during the high-load bench pulls were assessed using movement velocity and surface electromyography. Residual effects during the subsequent free-weight sets were assessed using repetition count, movement velocity, and surface electromyography. The crossover design allowed each participant to complete both loading conditions and therefore serve as his own control.

Visão geral do estudo

Status

Concluído

Condições

Intervenção / Tratamento

Descrição detalhada

This study used a randomized, counterbalanced crossover design to compare the acute effects of high-load chain-based variable resistance (VR) and free-weight (FW) resistance during the bench pull exercise. Resistance-trained men completed both experimental conditions in separate sessions, with the order of conditions randomized and the sessions separated by 72 hours.

Before each experimental condition, participants completed a standardized general warm-up and a bench pull-specific warm-up, followed by a 10-minute rest period. In each session, participants performed one set of three bench pull repetitions at approximately 85% of their free-weight one-repetition maximum (1RM). In the VR condition, external resistance was provided by a combination of barbell load and chains, with chains contributing approximately 20% of the effective mean total load. In the FW condition, external resistance was provided entirely by the barbell.

After the high-load bench pull, participants rested for 3 minutes and then completed three standardized sets of free-weight bench pulls at approximately 75% 1RM, with 3-minute rest intervals between sets. Each subsequent set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion.

Movement velocity and surface electromyography were recorded during the high-load bench pulls to evaluate direct exercise responses. During the subsequent free-weight sets, repetition count, movement velocity, and surface electromyography were assessed to evaluate residual effects of the preceding high-load condition. The crossover design allowed each participant to complete both loading conditions and therefore serve as his own control.

Tipo de estudo

Intervencional

Inscrição (Real)

15

Estágio

  • Não aplicável

Contactos e Locais

Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.

Locais de estudo

    • Tianjin Municipality
      • Tianjin, Tianjin Municipality, China, 510760
        • Tianjin University of Sport

Critérios de participação

Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.

Critérios de elegibilidade

Idades elegíveis para estudo

18 anos a 30 anos (Adulto)

Aceita Voluntários Saudáveis

Sim

Gêneros Elegíveis para o Estudo

Macho

Descrição

Inclusion Criteria:

  • Male adults aged 18-30 years.
  • At least 1 year of resistance-training experience.
  • Proficiency in the bench-pull technique.
  • Bench-pull one-repetition maximum (1RM) of at least 1.0 × body mass.
  • No current use of medications that could affect neuromuscular performance.
  • No history of cardiovascular, neurological, or metabolic disease.
  • No upper-body musculoskeletal injury within the previous year.
  • Willing and able to provide written informed consent.

Exclusion Criteria:

  • Consumption of caffeine within 12 hours before testing.
  • Consumption of alcohol within 24 hours before testing.
  • Performance of any upper-body pulling exercise within 48 hours before testing.

Plano de estudo

Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.

Como o estudo é projetado?

Detalhes do projeto

  • Finalidade Principal: Ciência básica
  • Alocação: Randomizado
  • Modelo Intervencional: Atribuição cruzada
  • Mascaramento: Nenhum (rótulo aberto)

Armas e Intervenções

Grupo de Participantes / Braço
Intervenção / Tratamento
Experimental: Variable Resistance, Then Free Weight

Participants completed the high-load variable-resistance bench-pull condition during the first experimental session and the high-load free-weight bench-pull condition during the second experimental session. The two sessions were separated by 72 hours. In each session, the high-load bench pull was followed after 3 minutes by three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum.

Participants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum. External resistance was provided by a combination of barbell load and chains, with the chains contributing approximately 20% of the effective mean total load. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed.

Participants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum, with the external resistance provided entirely by the barbell. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed.

Experimental: Free Weight, Then Variable Resistance

Participants completed the high-load free-weight bench-pull condition during the first experimental session and the high-load variable-resistance bench-pull condition during the second experimental session. The two sessions were separated by 72 hours. In each session, the high-load bench pull was followed after 3 minutes by three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum.

Participants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum. External resistance was provided by a combination of barbell load and chains, with the chains contributing approximately 20% of the effective mean total load. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed.

Participants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum, with the external resistance provided entirely by the barbell. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed.

O que o estudo está medindo?

Medidas de resultados primários

Medida de resultado
Descrição da medida
Prazo
Average Mean and Peak Velocity During the High-Load Bench Pull
Prazo: Day 1 and Day 4, during the high-load bench-pull set

Movement velocity was measured using a linear position transducer sampling at 100 Hz. Mean velocity and peak velocity were obtained for each of the three repetitions performed during the high-load bench-pull set. For each loading condition, average mean velocity and average peak velocity were calculated by averaging the corresponding values across the three repetitions. Velocity was expressed in meters per second (m·s-¹).

Day 1 and Day 4, during the high-load bench-pull set
Normalized Surface Electromyography Amplitude During the High-Load Bench Pull
Prazo: Day 1 and Day 4, during the high-load bench-pull set

Surface electromyography was recorded from the right latissimus dorsi, teres major, posterior deltoid, and middle trapezius. Root mean square amplitudes were normalized to the maximal root mean square amplitude obtained during maximal voluntary isometric contraction testing and expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Mean and peak electromyography amplitudes were obtained for each repetition and averaged separately across the three high-load repetitions.

Day 1 and Day 4, during the high-load bench-pull set
Number of Valid Repetitions Completed During Subsequent Free-Weight Bench-Pull Sets
Prazo: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set

Participants completed three subsequent free-weight bench-pull sets at approximately 75% of one-repetition maximum. Each set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion. The number of valid repetitions completed in each of the three sets was recorded.

Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Movement Velocity During Subsequent Free-Weight Bench-Pull Sets
Prazo: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set

Mean and peak velocity were measured during each of the three subsequent free-weight bench-pull sets. For the repetition-matched analysis, velocity outcomes included average velocity, fastest-repetition velocity, matched-final velocity, velocity maintenance, and velocity decline. Repetition matching was performed separately for each participant and corresponding set using the smaller number of valid repetitions completed across the two experimental conditions.

Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Normalized Surface Electromyography Amplitude During Subsequent Free-Weight Bench-Pull Sets
Prazo: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set

Mean and peak surface electromyography amplitudes were assessed for the right latissimus dorsi, teres major, posterior deltoid, and middle trapezius during each of the three subsequent free-weight bench-pull sets. Electromyography amplitudes were normalized to maximal voluntary isometric contraction and expressed as %MVIC. For the repetition-matched analysis, mean and peak amplitudes were averaged separately across all included repetitions within each set.

Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set

Colaboradores e Investigadores

É aqui que você encontrará pessoas e organizações envolvidas com este estudo.

Patrocinador

Datas de registro do estudo

Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados ​​pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.

Datas Principais do Estudo

Início do estudo (Real)

15 de abril de 2026

Conclusão Primária (Real)

30 de junho de 2026

Conclusão do estudo (Real)

1 de setembro de 2026

Datas de inscrição no estudo

Enviado pela primeira vez

17 de setembro de 2026

Enviado pela primeira vez que atendeu aos critérios de CQ

22 de setembro de 2026

Primeira postagem (Real)

29 de setembro de 2026

Atualizações de registro de estudo

Última Atualização Postada (Real)

29 de setembro de 2026

Última atualização enviada que atendeu aos critérios de controle de qualidade

22 de setembro de 2026

Última verificação

1 de setembro de 2026

Mais Informações

Termos relacionados a este estudo

Outros números de identificação do estudo

  • TJUS 2025-117

Informações sobre medicamentos e dispositivos, documentos de estudo

Estuda um medicamento regulamentado pela FDA dos EUA

Não

Estuda um produto de dispositivo regulamentado pela FDA dos EUA

Não

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