§ Claim under review · Mixed
"The debate over whether to combine aerobic (cardio) and strength training is settled — both are needed, and when done in the same session strength training should be performed before cardio, since separating them by 24 hours reduces fatigue and improves adaptation, though consistency matters more than following a 'perfect' program; with age, preserving muscle, strength and power becomes the priority, and even minimal weekly sessions (1+1) produce meaningful benefits."
Verdict
Mostly accurate
Confidence
MediumSummary
This post about combining cardio and strength training is mostly accurate and traces to real research. The author, Mikel Izquierdo, is a verifiable professor at the Public University of Navarra who led a 2025 global expert consensus on exercise for healthy aging, so this is not recycled fitness content. The strongest parts of the claim hold up well: guidelines clearly recommend doing both types of training rather than choosing one, and a randomized trial in women aged 60 to 74 found that just one strength session and one aerobic session per week produced real gains in strength, fitness and body composition. The weakest part is the "strength first, then cardio" rule. The main meta-analysis on training order found a benefit for only one outcome, lower body strength, and no benefit at all for muscle growth, aerobic capacity or body fat, and a 2025 review concluded training order is not the main factor behind interference between the two. The 24 hour separation advice is supported by review evidence but the size of the real world benefit is modest and mostly studied in trained people. One thing could not be checked: the El País article the post links to could not be located, so whether it frames these points the same way is unknown.
The readings
key figures from the evidenceweighted mean difference in lower-body dynamic strength, strength-first order
participants in Hunter et al. 1+1 vs 2+2 vs 3+3 frequency trial
Why this verdict
Evidence
The poster is who he says he is. Mikel Izquierdo is verifiable as a Full Professor in the Department of Health Sciences at the Public University of Navarra, affiliated with Navarrabiomed, with an extensive publication record in strength training, frailty and concurrent training. He is the lead author of the 2025 ICFSR global consensus on exercise for healthy longevity in older adults. This is not an anonymous fitness account making claims about research it did not conduct.
"Both are needed." This is the least contested element. Major guideline documents, including the ICFSR consensus Izquierdo led, recommend both aerobic and resistance training for older adults rather than one or the other. There is no meaningful scientific dispute on this point.
"Strength first, then cardio." The evidence here is real but considerably narrower than the phrasing implies. The Eddens et al. meta-analysis found that a resistance-then-endurance sequence produced a benefit for one specific outcome, lower-body dynamic strength, with a weighted mean difference of 6.91% change (95% CI 1.96 to 11.87, p = 0.006). Critically, the same analysis found no effect of exercise order on lower-body static strength, muscle hypertrophy, maximal aerobic capacity, or body fat percentage. The authors noted that an order effect was observed for only one of the outcomes examined. Cadore and Izquierdo's own 2012 trial in elderly men supports strength-first for neuromuscular and cardiovascular gains, which is the specific evidence base behind the poster's recommendation. A 2025 semi-systematic review concluded that sequence is not the leading cause of interference effects on hypertrophy and maximum strength in humans, while still noting practical reasons to place strength work first. A 2020 PLOS One trial found same-day order affected some indices of power development but not strength, lean mass, or aerobic fitness.
"Separating by 24 hours reduces fatigue and improves adaptation." Supported directionally. The 2024 Medicine review reports that a 24-hour recovery period between resistance and endurance training produced better outcomes than same-session training, and also notes that a 24-hour interval is advisable if the goal is maximizing endurance adaptations. The PLOS One authors suggested that to maximize power-related adaptations, resistance training should be performed in isolation with at least 24 hours of recovery, or scheduled first if performed on the same day. The magnitude of this advantage is modest, and much of the relevant research involves trained individuals.
"1+1 weekly sessions produce meaningful benefits." Directly and specifically supported. Hunter et al. randomized 72 women aged 60 to 74 to one of three frequencies: one aerobic plus one resistance day per week (1+1), 2+2, or 3+3. After 16 weeks, all groups increased fat-free mass, strength and aerobic fitness and decreased fat mass, with no time-by-group interaction for any fitness or body composition variable. A separate report on the same dataset found that frequency did not differ in improving strength, endurance, or lower-extremity functional task outcomes. The "1+1" notation in the post matches this study's terminology exactly, which strongly suggests this is the intended source.
"With age, preserving muscle, strength and power becomes the priority." Consistent with the ICFSR consensus and with the broader Cadore-Izquierdo body of work on power training in older adults. This is a prescriptive emphasis rather than a testable empirical finding, and it does not mean aerobic training is dropped.
Findings
✓ What's accurate 6
- Both aerobic and resistance training are recommended together, not as alternatives. Well supported by consensus guidelines.
- The poster's identity, institutional affiliation, and research record on concurrent training are verifiable.
- There is genuine peer-reviewed evidence favoring a strength-before-endurance sequence, including a meta-analysis finding and the poster's own trial in older men.
- Separating modalities by roughly 24 hours is supported by review-level evidence as reducing interference and aiding adaptation.
- The "1+1" claim maps onto a specific randomized trial in which one aerobic plus one resistance session weekly produced significant gains in strength, aerobic fitness and body composition in older women, statistically indistinguishable from higher frequencies.
- Prioritizing muscle, strength and power with age is consistent with the ICFSR consensus.
≈ What's misleading 5
- **Exaggeration / omitted qualifier (intra-session order):** the claim presents "strength first" as a general rule. The best available meta-analysis found an order benefit for one outcome only, lower-body dynamic strength, and explicitly no benefit for hypertrophy, static strength, aerobic capacity or body fat. A 2025 review concluded sequence is not the primary driver of interference. The recommendation is defensible as a practical default but is not the robust finding the phrasing suggests.
- **Omitted qualifier (goal dependence):** the order recommendation is goal-dependent. If endurance performance is the training priority, the rationale for putting strength first weakens. The claim does not distinguish goals.
- **Subgroup generalization:** the strongest supporting evidence for both the "strength first" order and the "1+1" dose comes from older adults, and in the 1+1 case specifically from previously sedentary women aged 60 to 74. The claim as summarized reads as universally applicable.
- **Overreach in "settled":** the narrow proposition that both modalities are needed is indeed settled. But the summary bundles the order question and the 24-hour question under the same certainty, and those remain actively debated in the literature.
- **Unfalsifiable framing:** "consistency matters more than following a perfect program" is a reasonable practical stance but is a judgment, not a research finding, and is presented alongside empirical claims as if it were one.
? What's uncertain 5
- The El País English-language feature could not be located. Its existence, content, and whether it accurately reflects the research are unverified.
- Whether the El País article itself makes these claims in this form, or whether the compression occurred in the Instagram caption or at intake, cannot be determined.
- The size of the practical benefit of 24-hour separation for a typical recreational exerciser is not well quantified in the sources retrieved.
- Whether "1+1" findings extend to men, to younger adults, or to already-trained individuals is not established by the Hunter trial.
- The specific Navarrabiomed research on "concurrent training, functional capacity, and healthy longevity" referenced in the caption was not isolated as a single identifiable paper. ---
Sources
8 of 10 linked to records**Izquierdo M, de Souto Barreto P, Arai H, et al. "Global consensus on optimal exercise recommendations for enhancing healthy longevity in older adults (ICFSR)." *J Nutr Health Aging* 2025;29(1):100401**
**Hunter GR, Bickel CS, Fisher G, Neumeier WH, McCarthy JP. "Combined aerobic and strength training and energy expenditure in older women." *Med Sci Sports Exerc* 2013;45(7):1386-93**
**Eddens L, van Someren K, Howatson G. "The Role of Intra-Session Exercise Sequence in the Interference Effect: A Systematic Review with Meta-Analysis." *Sports Med* 2018**
**Cadore EL, Izquierdo M, Alberton CL, et al. "Strength prior to endurance intra-session exercise sequence optimizes neuromuscular and cardiovascular gains in elderly men." *Exp Gerontol* 2012;47(2):164-9**
**Schumann M et al. (order-of-training trial): "Order of same-day concurrent training influences some indices of power development, but not strength, lean mass, or aerobic fitness…" *PLOS One* 2020**
**"Optimizing concurrent training programs: a review." *Medicine* 2024;103(52)**
**"The effects, mechanisms, and influencing factors of concurrent strength and endurance training with different sequences: a semi-systematic review." *Frontiers in Sports and Active Living* 2025**
**Hunter GR, Martins C, et al. "Frequency-dependent adaptations… 16 to 32 weeks of combined aerobic and resistance training in older women." *Eur J Appl Physiol* 2026**
**Navarrabiomed / Public University of Navarra institutional pages and Google Scholar profile for Mikel Izquierdo**
**The referenced El País English-language feature**