My call: interval training with short bouts is the most sensible approach given the mechanism and the limited evidence, but the head-to-head trial against continuous exercise has never been done, so the recommendation is based on plausibility and one small study, not proof. like what resistance weight traing, walking? what?

The short version: walking intervals are the safest starting point for long COVID, and creatine plus exercise has two small long COVID studies but no head-to-head comparison against exercise alone.

For someone who crashes after exertion, walking intervals are the most sensible starting modality. The narrative review on long COVID exercise found that a mixed program starting with low-intensity continuous walking and progressing to short interval bouts (3 minutes at 20–30% of peak work rate, 4 minutes at 50%) improved functional capacity in 12 patients aged 26–84, and 9 of the 12 tolerated the progression [28]. Walking is low-impact, easy to dose in minutes, and the rest intervals let the blood clear metabolic waste before the next effort. Resistance weight training is also supported: the same review found that low- or high-intensity aerobic training combined with resistance training produced comparable improvements in lower limb muscle in COVID patients with sarcopenia [28]. But resistance training requires more supervision to avoid straining, and the crash risk is less studied for weights than for walking.

On creatine plus exercise versus exercise alone, the evidence is thin. Two small 2024 studies tested creatine in long COVID. One gave 8 weeks of creatine-glucose (4 g creatine, 2 g glucose, twice daily) and reported reduced clinical features [11]. Another combined creatine with breathing exercises and found reduced respiratory discomfort [11]. Neither compared creatine plus exercise against exercise alone. The broader creatine literature shows that creatine combined with resistance training improves strength and lean mass more than training alone in older women [1] and young adults [2], and that long-term use appears safe for kidney function in healthy people [3, 12]. But those studies were not in long COVID patients, and the endurance benefit of creatine is absent — it does not improve prolonged submaximal exercise [6].

My call: start with walking intervals — 2–4 minutes of gentle walking, equal rest, monitor symptoms for 24 hours after each session. Add resistance training only after you tolerate walking without crashing. Creatine (3–5 g/day) is low-risk and might help, but the evidence that it adds anything beyond exercise alone in long COVID is not there yet. Confidence: moderate for walking intervals as a starting strategy, low for creatine plus exercise over exercise alone.