PR-TF 41 is a 26.5 km one-way climb from sea level at Playa del Socorro to La Rambleta, beside Teide’s upper cable-car station at 3,555 m. The park’s estimate is 14½ hours, with 3,619 m of ascent and very little descent. This is an extreme mountain day for fit, experienced hikers who are ready for altitude; it is not a short way to reach the summit. The route ends at La Rambleta, not Teide’s peak, and it is not a loop. Work out how you will descend before setting off.
The final approach shares the PNT 07 trail from Montaña Blanca to La Rambleta, which requires advance authorization and specific mountain equipment; the rest of Route 040 is listed as free access without a reservation. The separate PNT 10 path from La Rambleta to Teide’s summit needs another authorization and is not part of this route. Keep those two permit steps clear when planning; the summit is beyond this trail’s finish.