I have said it before and no doubt I will say it again: If pressed for time, don't skip the gym altogether — just shorten your workout.
When you're pressed for time, use this quick elliptical workout I created. It's only 22 minutes long including warmup and cooldown, and features really short and effective intervals. Using quick intervals makes the workout intense and is great for burning calories. Remember to work honestly within your rate of perceived exertion (RPE) and work between easy (1-3), medium (4-7), and hard (8-10) amounts of exertion.

To see the workout just read more.

Set incline to 20 percent and get working:

Warm Up
00:00-03:00 Resistance 3
03:00-05:00 Resistance 5

Quicky Intervals For 5 minutes
Resistance between 5 and 7
05:00-05:08, RPE 8-10
05:08-05:20, RPE 4-7
05:20-05:28, RPE 8-10
05:28-05:40, RPE 4-7
05:40-05:48, RPE 8-10
05:48-06:00, RPE 4-7
Repeat 4 more times

Recover
10:00-12:00, level 7, Backward, RPE 3-4
Focus on your hamstrings

Quicky Intervals For 5 minutes
Resistance between 5 and 7
12:00-12:08, RPE 8-10
12:08-12:20, RPE 4-7
12:20-12:28, RPE 8-10
12:28-12:40, RPE 4-7
12:40-12:48, RPE 8-10
12:48-13:00, RPE 4-7
Repeat 4 more times

Cool Down
17:00-20:00 level 5
20:00-22:00 level 3

To make the workout even more varied, focus on your arms powering the motion during the intervals on even minutes. Alternate with pushing versus pulling as you work your arms to balance the muscle of your upper body.

Click here for printable version.

Source