PMID 40943540

Research
All papers

Anti-Inflammatory and Antioxidant Effects of HIIT in Individuals with Long COVID: Insights into the Potential Role of Triphala

Question

Does supervised HIIT, alone or combined with Triphala supplementation, reduce inflammatory and oxidative-stress biomarkers in adults with long COVID?

Summary

In screened adults with long COVID symptoms, 8 weeks of supervised cycling HIIT with or without Triphala was associated with within-group reductions in inflammatory and oxidative-stress biomarkers, but between-group interactions were not significant. Minor symptoms occurred in a few HIIT participants and no serious adverse events were reported.

Methodology

  • Adults with prior COVID-19 and persistent long COVID symptoms/post-exertional malaise symptoms.
  • 104 participants.
  • Stationary cycling.
  • Work intervals: 4 min at 85% HRpeak.
  • Recovery: 3 min active recovery at 60% HRpeak.
  • Intensity: 85% HRpeak work, 60% HRpeak recovery, 50-60 rpm.
  • About 38 min including 5 min warm-up and 5 min cool-down.
  • 3 sessions/week.
  • 8 weeks.
  • Randomized controlled trial with control/placebo, HIIT, and HIIT plus Triphala groups
  • Inflammatory cytokines, Oxidative stress, Safety labs, and Exercise symptoms were tracked.

Outcomes

Inflammation

HIIT arms had within-group IFN-gamma and TNF-alpha reductions, but interactions were nonsignificant.

IFN interactions p=0.837; TNF interactions p=0.175.

Mixed

Oxidative stress

MDA and protein carbonyls decreased within exercise groups, but between-group interactions were nonsignificant.

MDA interaction p=0.710; protein carbonyl interaction p=0.968.

Mixed

Safety

No serious adverse events or ALT/creatinine changes; four minor symptom events occurred.

ALT p=0.315; creatinine p=0.249; minor events in 4 participants (5.97%).

Mixed

Insights

  • A clinical 4 x 4 cycling format can be monitored with HRpeak, RPE, dyspnea, and symptom checks.
  • For long COVID, absence of serious events in a screened lab sample does not establish safety for unsupervised use.
  • Between-group nonsignificance should temper biomarker benefit claims.

Limitations

  • Young highly screened long-COVID sample
  • Nonsignificant group-by-time interactions
  • No PESE/PEM diary
  • No Triphala-only group
  • Limited biomarker panel
  • Variable compliance
  • Clinical supervision limits generalizability

Safety

  • No serious adverse events were reported.
  • Four participants (5.97%) experienced minor events in the final week during the fourth HIIT cycle: leg muscle fatigue, dizziness, and transient hypotension; none discontinued.
  • The protocol was supervised by licensed physical therapists with continuous adverse-event monitoring, but post-exertional symptom exacerbation within 24 h was not measured.