The study aimed to assess the proportion of aerobic and anaerobic energy contributions during resistance exercises performed at 80% of one‑repetition maximum (1‑RM) using the accumulated oxygen deficit (AOD) method. Four exercises were examined – half squat, bench press, triceps extension, and lat pull‑down – in a sample of 14 healthy men (average age 26.6 ± 4.9 yr). After establishing 1‑RM values, participants completed low‑intensity bouts at 12, 16, 20, and 24 % of 1‑RM across separate sessions to obtain VO₂ data, which were linearly extrapolated to predict VO₂ at 80 % 1‑RM. In a final session, participants performed each exercise to volitional exhaustion at 80 % 1‑RM while breath‑by‑breath gas exchange was recorded. The AOD (difference between predicted VO₂ demand and accumulated VO₂) represented anaerobic contribution, while the accumulated VO₂ (VO₂Ac) represented aerobic contribution. Results showed a predominance of anaerobic energy across all exercises, with mean anaerobic contributions of 77.7 % (bench press), 87.4 % (half squat), 63.9 % (triceps extension), and 72.0 % (lat pull‑down). The total energy demand (TED) and prediction errors (standard error of prediction, SEP) were larger for the half squat, indicating poorer estimation accuracy for this exercise. The authors discuss methodological concerns of AOD in resistance training, noting that muscle mass, exercise modality (free weights vs pulleys), and technical proficiency affect the linearity of VO₂ extrapolation and thus the reliability of anaerobic estimates. Comparisons with prior literature on cycling, running, and other resistance protocols highlight inconsistencies and the need for further validation of AOD for resistance exercises. The paper concludes that while AOD can reveal substantial anaerobic contributions, its accuracy varies by exercise, and additional studies are required to refine the method for resistance training contexts.
Topics
Applying Accumulated Oxygen Deficit (AOD) to Quantify Aerobic vs. Anaerobic Energy in Resistance Exercise
Explanation of the AOD concept, its calculation as the difference between predicted VO₂ demand and measured accumulated VO₂, and justification for its use in resistance training research.
Experimental Design: Six‑Session Protocol for 80% 1‑RM Testing Across Four Resistance Movements
Details of participant recruitment, anthropometric assessments, 1‑RM testing, low‑intensity VO₂ bouts (12‑24% 1‑RM), and the exhaustive 80% 1‑RM session, including cadence, equipment, and gas‑analysis procedures.
Anaerobic Dominance Findings: Exercise‑Specific Percent Contributions
Presentation of quantitative results showing anaerobic percentages for bench press (77.7 %), half squat (87.4 %), triceps extension (63.9 %), and lat pull‑down (72.0 %), along with associated aerobic percentages and total energy cost values.
Methodological Accuracy: Why the Half Squat Estimation Falters
Analysis of regression linearity, higher standard error of prediction, and potential technical skill deficits that lead to poorer AOD accuracy for the half squat compared with upper‑body exercises.
Muscle Mass, Exercise Modality, and Their Impact on Anaerobic Capacity Estimates
Discussion of how larger muscle groups (e.g., half squat) and free‑weight versus pulley systems influence AOD values, referencing prior studies on incline running and swimming limb contributions.
Contextualizing Findings Within Existing Energy‑Cost Literature
Comparison of the study’s AOD and TED values with those reported for cycling, running, and other resistance protocols, highlighting inconsistencies and the challenges of cross‑modal comparisons.
Future Directions: Validating AOD for Resistance Training Energy Assessment
Authors’ recommendations for additional validation studies, methodological refinements, and broader exercise selections to improve the reliability of AOD in resistance contexts.