§ Claim under review · Health
"MYTH: Cardio is the only way to lose weight. TRUTH: Resistance training builds muscle — and muscle burns fat even when you're resting. Stop chasing the treadmill alone. Real, lasting fat loss comes from building strength that works for you 24/7."
Verdict
Partially accurate but misleading
Confidence
HighSummary
This gym advertisement mixes a correct point with an exaggerated one. It is correct that cardio is not the only way to lose fat, and resistance training on its own has been shown in a large review of 58 studies to reduce body fat by about 1.5 percentage points compared to not exercising. It is also correct that muscle tissue burns more energy at rest than fat tissue does. However, the amount is far smaller than the post implies. Muscle burns roughly 13 calories per kilogram per day at rest, so gaining a few kilograms of muscle adds only about 25 to 65 calories a day, not enough to drive meaningful fat loss on its own. Research comparing exercise types actually found aerobic and combined training more effective than weights alone for reducing absolute fat mass, and the American College of Sports Medicine has described resistance training as ineffective for weight loss by itself. Resistance training's strongest proven benefit during weight loss is preserving muscle while you diet, not burning fat while you rest. The post cites no source and is promotional material for a paid gym.
The readings
key figures from the evidenceresting metabolic rate of skeletal muscle
body fat percentage reduction from resistance training vs control
increase in resting metabolic rate after 9 months of resistance training
Why this verdict
Evidence
On the metabolic rate of muscle tissue: The specific resting metabolic rates of major organs and tissues in the reference human were established by Elia in 1992 as 200 kcal/kg per day for liver, 240 for brain, 440 for heart and kidneys, 13 for skeletal muscle, 4.5 for adipose tissue and 12 for residual mass. In contrast to high-rate organs, resting metabolic rates of skeletal muscle (13 kcal/kg per day) and adipose tissue (4.5 kcal/kg per day) are low, so although skeletal muscle and adipose tissue are the two largest body components, their contribution to resting energy expenditure is limited. Converted, this is roughly 6 calories per pound (13 calories per kilogram) per day at rest for skeletal muscle.
On resistance training and fat loss: A meta-analysis of 58 studies found that compared to no-exercise control, resistance training reduced body fat percentage by 1.46 percentage points (95% CI 1.14 to 1.78), body fat mass by 0.55 kg (95% CI 0.34 to 0.75) and visceral fat by a standardised mean difference of 0.49.
On resistance versus aerobic training: A systematic review and meta-analysis of RCTs comparing resistance training, aerobic training and concurrent training concluded that while there are no differences in percent body fat loss between exercise modes, aerobic and concurrent training are more effective than resistance training alone in reducing absolute fat mass, and resistance training neither improved nor impeded fat mass loss when incorporated into concurrent training.
On guidelines: The ACSM position stand states that resistance training is ineffective for weight loss with or without diet restriction according to limited research evidence, but some limited data suggest resistance training enhances gain or maintenance of lean mass and loss of body fat during energy restriction.
On resistance training and resting metabolic rate: A trial found that 9 months of resistance training significantly increased resting metabolic rate by approximately 5% on average, with wide variability between individuals.
On preserving muscle during dieting: A meta-analysis found that resistance exercise added to diet-induced weight loss had no effect on total weight loss (mean difference -0.32 kg, 95% CI -1.00 to 0.35, p=0.35) but did preserve fat free mass. In obese elderly individuals, resistance training reduced 93.5% of caloric-restriction-induced lean body mass loss.
On the post-exercise "afterburn": A systematic review found training volume influenced EPOC magnitude and duration, and that short rest intervals increased EPOC magnitude but not overall energy expenditure. In older adults performing isocaloric bouts, EPOC magnitude was actually greater after aerobic exercise (40.1 kcal) than after resistance exercise.
Findings
✓ What's accurate 5
- Resistance training does build muscle. This is uncontested and reflected in the framing of the literature: resistance training is described as the gold standard exercise mode for accrual of lean muscle mass.
- Muscle tissue does have a higher resting metabolic rate than fat tissue, roughly three times higher per kilogram: 13 kcal/kg/day for skeletal muscle versus 4.5 kcal/kg/day for adipose tissue.
- Skeletal muscle is metabolically active around the clock, so the literal statement that muscle expends energy at rest is correct.
- The "myth" half of the post is genuinely a myth. Cardio is not the only way to lose fat. Resistance training alone produced statistically significant reductions in body fat percentage, fat mass and visceral fat versus no-exercise control.
- Resistance training has a real and well-supported role in body composition during dieting: it prevented roughly 93.5% of caloric-restriction-induced lean mass loss in obese elderly individuals.
≈ What's misleading 7
- Exaggeration of magnitude. The post implies the resting-metabolism effect is large enough to drive fat loss. It is not. At 13 kcal/kg per day for skeletal muscle, gaining a realistic 2 to 5 kg of muscle adds roughly 25 to 65 kcal per day. One commonly cited estimate puts it at roughly 30 kcal daily for 2.3 kg of muscle gained, equivalent to about half a digestive biscuit. Even the more generous whole-body measurement found only about a 5% increase in resting metabolic rate after 9 months of training.
- Mechanism substitution. The post says muscle "burns fat." Muscle expends energy and oxidises a mix of fuels. Fat loss occurs when total energy balance is negative, not because muscle tissue selectively consumes body fat. The post presents a metabolic-rate fact as if it were a fat-targeting mechanism.
- Omitted qualifier on effect size. The actual measured fat loss from resistance training alone is modest: 1.46 percentage points of body fat and 0.55 kg of fat mass versus control. The post's language ("real, lasting fat loss comes from building strength") implies a much larger and more decisive effect.
- Overcorrection against cardio. The post frames resistance training as superior. The comparative evidence does not support that framing: aerobic and concurrent training are more effective than resistance training alone in reducing absolute fat mass. The ACSM position stand goes further, describing resistance training as ineffective for weight loss with or without diet restriction based on limited evidence.
- Omission of diet. Nothing in the post mentions energy intake, despite the evidence base treating diet as the central driver: adding resistance exercise to diet-induced weight loss produced no additional weight loss, only preservation of fat free mass.
- The implied "24/7 afterburn" benefit is weak. In a controlled comparison, EPOC was greater after aerobic exercise than after resistance exercise at matched energy cost.
- No source cited. This is uncredited commercial advertising for a specific gym, with a call to action and phone number. The claim is presented as settled fact with no reference.
? What's uncertain 4
- The post makes no reference to any specific study, so there is no original source to trace. The investigation compared the claim against the best available scientific literature instead.
- Whether resistance training increases resting metabolic rate beyond what is explained by added lean tissue remains debated. The 9-month trial reported wide variability between individuals, partially accounted for by changes in fat-free mass and thyroid hormones.
- Effect sizes for resistance training and fat loss come largely from healthy adults and shorter interventions. Long-term (multi-year) fat loss outcomes from resistance training alone are not well established.
- Whether resistance training helps with weight maintenance over years, as opposed to short-term fat loss, was not resolved by the sources found.
Sources
6 of 7 linked to recordsWang Z. et al., "Evaluation of Specific Metabolic Rates of Major Organs and Tissues," and Wang et al. 2001, Obesity Research
Wewege M.A. et al. 2022, "The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat," Sports Medicine
"Comparison of concurrent, resistance, or aerobic training on body fat loss," 2025, JISSN
ACSM Position Stand, "Appropriate Physical Activity Intervention Strategies for Weight Loss," Med Sci Sports Exerc 2009
Resistance training during caloric restriction meta-analyses (Gray et al.; obese elderly RCT meta-analysis, PMC5946208)
Resistance training and RMR trial, Eur J Clin Nutr 2014
Farinatti et al. 2013, EPOC systematic review