Different workouts fight different kinds of inflammation

Exercise is a mainstay recommendation for women with overweight and obesity, and inflammatory markers are among the outcomes it is expected to improve. But exercise comes in distinct forms, from steady aerobic work to resistance training, combined programmes and high-intensity interval training, and it has been unclear whether they act on inflammation equally. A network meta-analysis can rank multiple interventions against each other even when few trials compare them directly. This review set out to compare and rank the four exercise types across a panel of inflammatory markers.

The authors searched Cochrane, Embase, PubMed, Web of Science and EBSCO for English-language randomised controlled trials published up to April 2023, then ran a random-effects network meta-analysis within a frequentist framework. In total, 75 articles covering 4048 participants were included. The interventions compared were aerobic exercise, resistance training, combined aerobic and resistance exercise, and high-intensity interval training. Outcomes were inflammatory markers including C-reactive protein, tumour necrosis factor-α, interleukin-6, leptin and adiponectin, with evidence graded using the GRADE approach.

Resistance training ranked highest for reducing C-reactive protein, with a standardised mean difference of 0.79 in favour of training. Aerobic exercise ranked best for lowering tumour necrosis factor-α, also with a standardised effect of 0.79. Combined aerobic and resistance exercise led the rankings for interleukin-6, with an effect of 0.77, and for leptin, at 0.96. High-intensity interval training was the best suited to raising adiponectin, a marker where an increase is the favourable direction, with an effect of 0.99. No single exercise type dominated across all markers.

The review confirms that exercise shifts inflammatory markers in women with overweight and obesity, and adds something previous pairwise meta-analyses could not: a ranking across four exercise types at once. The complication is that the ranking changes depending on which marker you care about, which argues against declaring any single format the anti-inflammatory exercise. Because network meta-analysis leans partly on indirect comparisons, head-to-head trials could still reshuffle the order. Which of these markers matters most for long-term health outcomes also remains an open question.

For women carrying extra weight, this is a reason to think the choice between weights, cardio, a mix, or intervals is less about finding the one true answer and more about what each does best. Lifting looked strongest for C-reactive protein, the most commonly tested inflammation marker, while mixing aerobic and resistance work led for interleukin-6 and leptin. The practical reading is that varied training plausibly covers more of the inflammatory picture than any single format, though this review cannot prescribe a programme.