Can speed practice alone help long distance endurance?

If I only practice to improve the speed in short distance, will it help increase the endurance needed for long distance? In other words, say I have trained for several months for (only) speed, could I, one day, suddenly find myself swimming long distance without feeling tired? Yes. Sole commitment to speed development may lead to improvement over longer distances. It would typically do so indirectly as a result of some drastic improvement in swim efficiency. So if you're under the impression that serious focus on speed development had allowed you to book your longer distances without feeling tired, that's probably as a result of some improvement in swim efficiency. The slower you are, the more this principle probably applies. That's a fair and safe answer to your question. Now, recently science has (for some reasons) tackle on this matter quite seriously (even though some study results remain controversial). There's this funny name they've been given to some basic anaerobic capacity intervals. Tabata. No matter the protocol, let's not hunt for magic hidden behind specific interval duration right? OK protocol put aside, there's something quite appealing to some hypothesis that have been issued. The idea is that the bottleneck in improving in your individual anaerobic threshold and your anaerobic capacity are common in few important aspect. 1. In both cases, need be for using fast twitch type IIa muscle fibers. 2. Both are somehow limited by the level of your O2 accumulated deficit 3. Both are somehow limited by your ability to metabolize, buffer and tolerate high levels of lactate So. The point on which people tend to argue is: Would 40s long intervals be the best way to increase both Max O2 peak consumption and thresholds? My opinion no. But the point on which several people (scientists and coaches) tend to agree, is that anaerobic capacity development has a favorable impact on one's ability to metabolize, buffer and tolerate high levels of lactate as well as to deal with high accumulated O2 deficits as well as to use a more specialized and powerful muscle mass. That, certainly helps any following threshold development phase. And another interesting point that may interests you, given you refer to this apparent ease in maintaining endurance pace. Many coaches and scientists believe that a period of anaerobic capacity development prior a taper has a favorable impact on threshold based performances. Cyclists probably lead in this regard, several include short interval development as a means to trigger a peak for a 40k time trial event (pure threshold event).

If I only practice to improve the speed in short distance, will it help increase the endurance needed for long distance? In other words, say I have trained for several months for (only) speed, could I, one day, suddenly find myself swimming long distance without feeling tired? Yes. Sole commitment to speed development may lead to improvement over longer distances. It would typically do so indirectly as a result of some drastic improvement in swim efficiency. So if you're under the impression that serious focus on speed development had allowed you to book your longer distances without feeling tired, that's probably as a result of some improvement in swim efficiency. The slower you are, the more this principle probably applies. That's a fair and safe answer to your question. Now, recently science has (for some reasons) tackle on this matter quite seriously (even though some study results remain controversial). There's this funny name they've been given to some basic anaerobic capacity intervals. Tabata. No matter the protocol, let's not hunt for magic hidden behind specific interval duration right? OK protocol put aside, there's something quite appealing to some hypothesis that have been issued. The idea is that the bottleneck in improving in your individual anaerobic threshold and your anaerobic capacity are common in few important aspect. 1. In both cases, need be for using fast twitch type IIa muscle fibers. 2. Both are somehow limited by the level of your O2 accumulated deficit 3. Both are somehow limited by your ability to metabolize, buffer and tolerate high levels of lactate So. The point on which people tend to argue is: Would 40s long intervals be the best way to increase both Max O2 peak consumption and thresholds? My opinion no. But the point on which several people (scientists and coaches) tend to agree, is that anaerobic capacity development has a favorable impact on one's ability to metabolize, buffer and tolerate high levels of lactate as well as to deal with high accumulated O2 deficits as well as to use a more specialized and powerful muscle mass. That, certainly helps any following threshold development phase. And another interesting point that may interests you, given you refer to this apparent ease in maintaining endurance pace. Many coaches and scientists believe that a period of anaerobic capacity development prior a taper has a favorable impact on threshold based performances. Cyclists probably lead in this regard, several include short interval development as a means to trigger a peak for a 40k time trial event (pure threshold event).