I'm an amateur, but refer to your site often for ideas about different exercises to perform. I have a question about how much rest is acceptable between sets. I'm currently working from home and while it's been difficult to find time for a dedicated chunk of time for a workout during the day, I have been able to do a set here and there throughout the day. Using a single leg squat (aka "Pistol") as an example, I'll do a set to failure on each leg (right now that's 5, but it was only 4 a couple of weeks ago!) then get back on the phone and computer. A while later (maybe 5-10 minutes, sometimes an hour) I'll go do another set. I'll do at least three sets throughout the day, often it's four or five sets. I still have a normal split schedule, I won't do legs again for another few days.
Is there a benefit I am missing by not doing 2-4 sets with only a few minutes of rest? Doing it this way has been a great for my motivation. It's really easy to talk myself into knocking out "just one more set" at various times during the day.
That is kind of how I began weight training as a teenager, taking very long rests between sets. I spent more time station surfing on my shortwave radio than working out, so I took hours to complete a workout.
Generally, as you know, you would take a few minutes between sets. By taking longer rest, you will basically forgo two benefits that may or may not be important to you at this point. First, by training with less rest between sets, you achieve a specific type of muscular endurance. Unless you are in a sport that requires this type of endurance, or will be required to train this way by your strength and conditioning coach, you are probably not missing out on much, particularly since that type of endurance is the first to go during periods of detraining (aka: lay offs).
Secondly, by waiting so long, your muscles will cool down between sets. Typically, you would begin an exercise by performing a warm-up set of approximately half of your workout resistance before your first workout set. The warm up preceding the workout set assists in several ways. (1) Reduces the chance of injury by warming the specific muscle groups and joints. (2) Allows you to rehearse the motor skill required for the movement. (3) Allows you to use greater resistance, or greater intensity to the exercise.
If you take more than several minutes rest between sets, you may need to rewarm-up the muscle to achieve these benefits. However, since you consider yourself a novice, you'll make progress no matter what you do and ironically, may have a lower risk of hurting yourself as a more advanced exerciser.
Although you workout to failure now, your ability to push yourself harder during your workouts will actually increase as you progress throughout the years. This means performing a warm-up set and taking only modest rest periods between sets will be more important for those above mentioned benefits when you are more advanced, using those greater resistances.
Incidentally, despite popular beliefs, it is not necessary to workout to failure. If you look at the training styles of Olympic weightlifters and Powerlifters, they typically avoid working out to failure, only failing periodically by accident. Instead, they commonly workout one repetition short of failure during their workout sets. Even for bodybuilding, training to consistently to failure is not only not necessary, it can even lead to premature stagnant progress and burnout.
If you train just short of failure for some time, you will find on those reps that you can just barely manage the last rep, you will be more likely to achieve that last rep since you'll have taught your body to success rather that to fail each set. You will also be able to make more long term progress working out just short of failure. It is much easier to overtrain when working out to failure and overtraining invites stagnated progress. In my opinion, training to failure should only be practiced sparingly, if at all.
Also see Weight Training: Applied Research Findings: Rest Between Sets.