The cramped conditions and long periods of being less active on a flight can cause pain, stiffness or swelling of your legs. Being less active can lead to slow blood flow in your veins which increases your risk of developing a blood clot, known as deep vein thrombosis (DVT). DVTs most commonly form in the legs.

While flying is a highly efficient mode of transport, it is generally considered physiologically taxing on the human body rather than "good" for it. The primary challenge is the "rarefied air" within the cabin, which is typically pressurized to an altitude of 6,000 to 8,000 feet. This results in lower oxygen saturation in the blood, which can lead to fatigue, headaches, and dizziness, especially for those with underlying respiratory or cardiac conditions. Furthermore, cabin humidity often drops below 20% (drier than the Sahara Desert), leading to significant dehydration, dry skin, and irritation of the nasal passages. The decrease in air pressure also causes gases trapped in the body to expand, leading to abdominal bloating and "airplane ear" as the Eustachian tubes struggle to equalize pressure. Additionally, sitting for prolonged periods increases the risk of Deep Vein Thrombosis (DVT), a condition where blood clots form in the legs. To mitigate these effects, health experts recommend staying hydrated, avoiding excessive caffeine or alcohol, and performing "seat exercises" or walking the aisle every hour to maintain healthy circulation.