Is Cialis useful for running?

Is Cialis useful for running? The evidence says no. In a controlled trial in athletes at normal oxygen levels, a single dose of tadalafil — the medicine in Cialis — did not change their maximal oxygen uptake (VO2max) or their aerobic and anaerobic thresholds. The studies that did find gains used sildenafil, not tadalafil, and only in thin air at real or simulated altitude, where the results are mixed.

Does Cialis improve endurance or VO2max?

No. In a double-blind crossover trial, 14 healthy male athletes did a maximal cycling test after tadalafil and after a placebo. Tadalafil "did not modify individual VO2max" or the ventilatory and anaerobic thresholds, and the authors concluded that it "does not substantially influence physical fitness-related parameters, exercise tolerance, and cardiopulmonary responses to maximal exercise in normoxia" (Di Luigi et al., Int J Sports Med 2008). No trial has tested it in runners: a PubMed search on 26 September 2026 found none. It is not approved for anything like this — the Australian leaflet says "Do not take CIALIS to treat any other complaints" (Cialis CMI), and it is for erectile dysfunction and the urinary symptoms of an enlarged prostate.

Does it help sprints or short, hard efforts?

Not in a way that shows up in performance. Twelve well-trained men did a 30-second all-out cycling sprint a day after tadalafil or a placebo; the dose "does not substantially influence anaerobic performance indices", though peak power came slightly sooner and blood lactate was higher three minutes after (Guidetti et al., Br J Sports Med 2008). The same research group also reported increases in testosterone and cortisol in saliva after a maximal test on tadalafil — a short stress-hormone response, measured in nine men (Di Luigi et al., J Clin Endocrinol Metab 2008).

What does Cialis do to blood pressure when you run?

It lowers it a little. The endurance trial tracked resting and exercise-induced blood pressure, and systolic pressure was lower on tadalafil before and after exercise (Di Luigi, Int J Sports Med 2008). In healthy men at rest the average fall is small — a mean maximum of 1.6/0.8 mmHg lying down (Cialis PI) — but dizziness and fainting are among the rarer serious side effects of ED medicines (healthdirect). Never take it with nitrates for chest pain or with "poppers" such as amyl nitrite: the Cialis leaflet rules both out (Cialis CMI).

Does Viagra or Cialis help at altitude?

Sildenafil sometimes did in thin air; tadalafil did not. At a simulated altitude of 3,874 m, sildenafil improved cardiovascular function and blood oxygen in 10 trained men and cut their 6 km cycling time-trial time by 15% on average — but most of the gain came from a subgroup of "responders", and at sea level it had no effect (Hsu et al., J Appl Physiol 2006). In 35 endurance-trained men and women at about 3,900 m it did not significantly improve time-trial performance (Jacobs et al., High Alt Med Biol 2011), and at a simulated 4,000 m it made no significant difference in 11 volunteers (Toro-Salinas et al., Int J Sports Med 2016). In 14 mountaineers and trekkers it raised maximum workload in low-oxygen tests and at Mount Everest base camp (Ghofrani et al., Ann Intern Med 2004).

Tadalafil was tested at 4,559 m in 23 people prone to high-altitude pulmonary oedema: it did not improve exercise capacity, while the steroid dexamethasone partly did (Fischler et al., Am J Respir Crit Care Med 2009). None of these studies looked at training or exercise adaptation over weeks. The wider question for sildenafil is answered in does Viagra enhance athletic performance?

What are the risks for a runner?

The usual side effects of tadalafil — headache, flushing, a blocked nose and indigestion (healthdirect) — plus back pain and muscle aches, which are among its most common; the figures are on does Cialis have benefits for bodybuilding? ED medicines are avoided if sexual exertion could put your heart at risk (healthdirect), and in Australia tadalafil "can only be supplied to Australians with a prescription" (TGA). It is not on WADA's Prohibited List; what drug tests look for is on can Viagra be detected in drug tests?

Does running help erectile dysfunction?

It may help prevent some causes: exercising more is on healthdirect's short list, with stopping smoking, losing weight and eating healthy food (healthdirect — Erectile dysfunction). That question has its own page — can exercise improve ED? — and so does the opposite one: can overtraining lead to ED?

The short answer

Cialis did not improve endurance, VO2max or sprint power in the athletes who were tested, and it is not approved for sport. The altitude gains people quote came from sildenafil in thin air, were not seen in every study, and were absent at sea level. More on ED medicines and particular conditions in our guide to Viagra and Cialis for sport, the lungs and other conditions.