The most common excuse for not exercising is lack of time. It is a horrible excuse, though. It is a matter of priority. It is a matter of opportunity.
I, personally, recommend 2-3 strength, 2-3 high-intensity interval resistance training sessions, and 2-3 cardio sessions per week. These can, believe it or not, be accomplished in as little as 20-30 minutes per session (if the goals aren’t particularly ambitions).
Strength. Doing the StrongLifts 5×5 with 60-second rests between sets can be accomplished in less than an hour (assuming approximately 30 seconds per repetition—3 exercises x 5 sets/exercise x 5 reps/set x 30 seconds per rep + 60 seconds/rest x 14 rests = 3090 seconds or 51.5 minutes). Two options to shorten this are super-sets or fewer sets. Super-sets—i.e., doing the three exercises in sequence with no rest—will shorten the workout by roughly 10 minutes. Few sets, e.g., 3 instead of 5, will cut the workout by 15 minutes. If progressing the weights, these options will build or sufficiently maintain muscle mass—not to win bodybuilding compositions, but to maintain function.
HIIRT. HIIRT workouts are great for elevating the metabolism and burning fat, as well as hitting some of the smaller muscle groups. These can be quick or long. On the quick side, 10-20 minutes can be effective. My go-to Bulgarian bag “core 550” [5 x 10 of 5 exercises—hinge, side swings (r-l), and spins (r-l)] takes less than 10 minutes depending on the rest between sets. Using weights or body weight exercises, two super-sets of 5 exercises performed for 10-15 repetitions, takes less than 20 minutes. Another option is timed sets of as many reps as possible (AMRAP)—just take extra care to maintain proper form throughout. Such workouts can be optimized to fit the available time (and, yes, there is available time, if you want there to be). Just be creative.
Cardio. High-intensity interval training (HIIT) can significantly shorten the time needed to improve cardiorespiratory endurance. Izumi Tabata’s research showed that VO2max can be improved in sessions as short as 4 minutes plus warm-up and cool-down. The researchers’ IE1 protocol employed 8 sets of 20 seconds of all-out effort (170% of VO2max) with 10-second recovery. It is not likely that anyone other than a well-trained athlete could do this workout (study participants included Olympic speed skaters, some of whom couldn’t complete the protocol). Nevertheless, a similar (I call it “Tabata”) workout could still produce effective results. If you only have twenty minutes, use it effectively. Any cardio is better than no cardio.
Time is not an excuse, then. Use the time you have well. If you don’t think you have time to exercise, look closer.
Be your best today; be better tomorrow.
Carpe momento!