When doing a high-intensity workout on a hydraulic machine, your body burns more sugar (carbs) for energy than when you lift weights, run, or bike at the same time.
Scientific Claim
During a 30-minute hydraulic resistance system (HRS) high-intensity interval training session, carbohydrate oxidation is significantly higher (2.98 ± 0.59 g·min⁻¹) than during resistance training (2.15 ± 0.40 g·min⁻¹), treadmill endurance (1.74 ± 0.44 g·min⁻¹), or cycling endurance (1.97 ± 0.45 g·min⁻¹) in healthy men.
Original Statement
“Regarding carbohydrates, the subjects displayed a significantly (p ≤ 0.05) greater carbohydrate expenditure when exercising with the HRS (2.98 ± 0.59 g·min⁻¹), compared with when using weights (2.15 ± 0.40 g·min⁻¹), treadmill (1.74 ± 0.44 g·min⁻¹), and cycle (1.97 ± 0.45 g·min⁻¹).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The claim reports direct, measured differences in carbohydrate oxidation using calibrated metabolic cart data. The statistical significance and specificity of values support definitive language within the study’s scope.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Systematic Review & Meta-AnalysisLevel 1aWhether HRS-HIIT consistently increases carbohydrate oxidation more than other modalities across populations.
Whether HRS-HIIT consistently increases carbohydrate oxidation more than other modalities across populations.
What This Would Prove
Whether HRS-HIIT consistently increases carbohydrate oxidation more than other modalities across populations.
Ideal Study Design
A meta-analysis of studies using indirect calorimetry to compare carbohydrate oxidation during 30-minute HRS-HIIT, resistance, treadmill, and cycling sessions in healthy adults, with standardized protocols and controlled diet.
Limitation: Cannot determine if higher carb use leads to faster fatigue or reduced fat loss over time.
Randomized Controlled TrialLevel 1bWhether HRS-HIIT causes greater carbohydrate oxidation than other modalities.
Whether HRS-HIIT causes greater carbohydrate oxidation than other modalities.
What This Would Prove
Whether HRS-HIIT causes greater carbohydrate oxidation than other modalities.
Ideal Study Design
A randomized crossover RCT with 40+ healthy adults performing all four 30-minute exercise conditions in random order, with continuous indirect calorimetry (k4B2 or equivalent), controlled diet, and fasting state, measuring carbohydrate oxidation rate as primary outcome.
Limitation: Does not assess long-term metabolic adaptation or glycogen depletion effects.
Prospective Cohort StudyLevel 2bWhether habitual HRS-HIIT users rely more on carbohydrates during exercise than users of other modalities.
Whether habitual HRS-HIIT users rely more on carbohydrates during exercise than users of other modalities.
What This Would Prove
Whether habitual HRS-HIIT users rely more on carbohydrates during exercise than users of other modalities.
Ideal Study Design
A 6-month prospective cohort study of 100+ regular exercisers using HRS, resistance, treadmill, or cycling, measuring substrate use via indirect calorimetry during standardized 30-minute sessions at matched RPE.
Limitation: Confounded by differences in training history and diet.
Evidence from Studies
Supporting (1)
The study found that working out with the hydraulic machine for 30 minutes burns more energy and uses more carbs than lifting weights, running, or cycling — exactly what the claim says.