Hello Larry Hulisz,
That depends on many things as the others mention. What do these people do on their off time from seeing you?
Then again, look at the work some people do on a daily basis. Some people do strength training and/or aerobics on the job daily, all day, and look at that, they survive.
The body will adapt to whatever it is put through, to a point, of course.
I would say, yes, it is fine, as long as you keep an eye on them and change the workouts.
Preferably, make the day in the middle an easier workout for a working rest session.
Yet another answer that is summarized by: It Depends. (But probably not a good idea for this one)
Whenever I design a workout for a client, there are a few things I ask myself regarding an exercise, and they go something along these lines…
1) Does it get my client closer to their goal?
2) Is this sound physiology and proper program design?
3) Can this client perform this exercise properly AND at its intended intensity?
So number one, I don’t know because I don’t have any information for this client.
Number two, depends, but probably not. As important as the exercise being performed is the ability of the body to recover. How your body responds and recovers is the true limiting factor in making gains, not how much weight is on the bar or how fast you do something. After a true HIIT workout, your body is going to need to recover.
Conditioning like sleds and sprints, I could buy that, but I would rather do it 2-3 days a week on non-consecutive days. Chances are if they actually need this training, their program should be well thought out. That doesn’t include 3 in a row with that type of training.
Not to mention true “HIIT” workouts are controversial themselves.
Number three, I don’t know and probably not. Day 3 is going to be tough, meaning probably a little slack. Lack of execution and good technique mixed with fatigue leads to injuries quickly.
In short, I wouldn’t do three days. Space it out, assign it for homework if you need to. There are hundreds of other things you could do.
Like many of the others, I try to break up HITT training and have a day or two of other types of exercise between sessions. I like to change the medium and intensity of the workouts I do with my client throughout the week. For example, if we do HITT one day, we may do pilates/yoga and stability exercises the next. Then we may do a pyramid or endurance exercise. It depends on their goal and what their current level of conditioning is.
Joshua’s answer brings the point home.
a) This is an ‘it depends’ situation. Since the condition of your clients is not available, it’s hard to say if 3 days-in-a row bursts are a great idea.
b) High intensity training can stress the body a lot! An extra rest day (or 2) can allow the body enough time to recover.
Kepp in mind that your clients ‘may feel O.K.’ the first time they do these bursts but…can they do it on a regular basis?
Good points to consider.