#1 rule of thumb before starting a workout routine = warmup FIRST. It goes with saying that if you want the best experience during your workout, take time to prepare the muscles ahead of time.
What is consider a good warm up duration?
it was preached that at least 5 minutes is a good amount of time to take to warm up. I personally find when I do an actual good warm up, it takes me 10-12 minutes and that is due to the fact I had a coach who taught me to warm up correctly before working out for my sport/event. He always preached a proper warm up is usually 10 minutes minimum. Although in all fairness, we can definitely go for a 5 minute warm up as long as you are spending time doing dynamic exercises in that 5 minutes. So duration is pending on the individual and what they need out of that particular warm up to best prepare them for the workout ahead.
What is considered a dynamic warm up / exercises?
A dynamic exercise is something that is actively done to warm up the muscles (opposite if static exercises). The reason behind dynamic exercises is because you are getting the HR up somewhat but not to the point of exhaustion or fatigue but enough where you feel like you have done something to increase HR. Some good exercises for a dynamic exercise(s) include: leg swings, butt kicks, fire hydrants, glute bridges, high knees, just to name a few (there are plenty more) and some choose to use the treadmill, elliptical or bike when warming up.
Choosing your warm up exercises wisely
When doing a proper warm up you need to consider which exercises will correspond well with the type of workout you have planned for the day. The truth is I see so many people rely on the treadmill to warm up and yet don’t go long enough or push themselves hard enough to 1) feel an increase in HR and 2) will have any correlation with the exercises they choose to do next. For example when I have a leg day where I am doing deadlifts or squats, my dynamic warm up is going to work the muscles that will help during those lifts specifically (I may or may not do some duration on the treadmill or bike) but afterwards I still want do some light sets of deadlifts and squats or do some glute bridges or something that will fire up those particular muscles. It isn’t to say that you have to do 10 minute worth of deadlifts or squats BUT do some low loaded sets that will help fire them legs up.
Basically in summary, warming up is an important aspect of fitness, it is helpful to start a workout with the best intentions by firing up those muscles and targeting the correct muscles to put forth the best effort. It doesn’t have to be long and grueling and it won’t kill you, but it definitely will get that HR up and can be any variation of fun exercises. Keep in mind that it should be dynamic in nature and spend some time thinking about what you want to get out of the workout so you can use that information to set the course for the warm up. Have fun!