Loads and movement speed affect energy expenditure during circuit resistance exercise

Kirk B. Roberson, Kevin Jacobs, Morgan J. White, Joseph Signorile

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

Circuit resistance training (CT) constitutes a high-intensity interval program commonly used to target weight loss; however, the loads and exercise patterns that maximize energy expenditure (EE) remain undetermined. We examined differences in EE among CT protocols using varying loads and contraction speeds in recreationally trained males and females. Seven males (age, 21.1 ± 0.5 years) and 8 females (age, 20.0 ± 0.9 years) performed 3 randomized CT protocols incorporating 3 circuits using heavy-load (80% 1-repetition maximum (1RM)) explosive (HLEC), heavy-load, controlled (2 s) (HLCC), and moderate-load (50% 1RM) explosive contractions (MLEC). Expired air was collected continuously before, during, and after exercise. Blood lactate was collected at rest, immediately postexercise, and 5 min postexercise. No significant differences were detected for resting EE; however, there was a significant difference among conditions during exercise (p = 0.034, ηp 2 = 0.229). Post hoc analysis revealed that MLEC produced significantly higher EE than HLCC, but not HLEC (p = 0.023). There was a significant difference among conditions for rate of EE during exercise (p = 0.003, ηp 2 = 0.361). Post hoc analysis revealed that HLEC produced a significantly higher EE rate than HLCC (p = 0.012) or MLEC (p = 0.001). A condition × sex interaction was seen for blood lactate changes (ηp 2 = 0.249; p = 0.024). Females produced significantly greater change for MLEC than HLEC (p = 0.011), while males showed no significant differences. Our results favor CT using MLEC for a higher EE during a full workout; however, the rate of EE was highest when using HLEC.

Original languageEnglish (US)
Pages (from-to)637-646
Number of pages10
JournalApplied Physiology, Nutrition and Metabolism
Volume42
Issue number6
DOIs
StatePublished - 2017

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Keywords

  • Blood lactate
  • Circuit training
  • Contraction speed
  • Energy expenditure
  • High-intensity
  • Recreationally trained
  • Resistance exercise
  • Weight loss

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Nutrition and Dietetics
  • Physiology (medical)

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