I remember there use to be an article which talked about contrast training and how Ben Johnson the Canadian sprinter used to have a power rack on the track, would perform a set of heavy squats and with short rest sprint. The article then said we could use the method with squats and sprints on the stationary bike.
I cannot find that article anymore but does any else remember seeing it and remember the reps and sprint duration or distance?
I remember seeing and reading it, but donât remember the details. I think it was from Poliquin. Maybe Staley. 
Hereâs Contrerasâs take on it:
There are a few others that turn up on google too.
Jogging my memory I remembered a Dan John article but it seems like it wasnât Ben Johnson but rather a hammer thrower Sergey Litvinov
Seems like a similar concept heavy lifting followed by sprints
Johnson, if he actually did this, had the objective of getting faster in mind. What result are you looking for? Do you believe that sprinting on a bike will elicit the same response as sprinting via running? They are very different physical activities.
A 75 second 400 is not a sprint.
Try it after front squatting 400 for reps
That still doesnât make it a sprint.
I would define a sprint as running at full speed, usually this is for a short distance, but in running terms 400m is considered short I guess. If I had just repped 400 for reps then 75 seconds for 400m would be my âfull speedâ . So in this isntance it still meets the definition of a sprint.
The best/worst leg pump I have ever had was when I ended my leg workout with a superset of 10 sets of 20 cal sprints on air dyne and leg extensions.
Whatâs your goal?
Not even elite 400 meter runners are running full speed. Theyâre running as fast as they can over 400 meters. The world record is just over 43 seconds so 75 seconds is almost twice as slow. Itâs 5 minute mile pace. I would argue that the 75 second 400 meters is about conditioning and not speed or strength. He isnât running it in 75 seconds because he is too fatigued to go faster, but because itâs doable, more than once, and it gives fitness benefits. If he truly ran 400 meters as fast as he could, the workout would be over after one set.
It has nothing to do with what Johnson was supposedly doing. Johnson did squats followed by a sprint in order to run faster. Litvinov was a thrower so his reasons for his workout were different. If he were trying to improve his 400, that wasnât the way to do it. It would be the opposite of what you should do.
I wasnât talking about an elite sprinter doing it, I was talking about a 50 year old male who doesnât run - Me. 75 sec for 400m for me would definitely be a sprint 
.
I agree that this particular workout is not designed to improve sprinting ability. I am also fairly sure although it has been a while since I read Danâs book with this workout in it, that he describes it as a ârunâ and not a sprint anyway.
If you are out of shape, you wonât even finish if you are running as fast as you can. With that said, with a little training a 75 second 400 would be doable even for someone as young as you.
You arenât wrong about someone out of shape not finishing. I know when I was running we used to do 10 x 400 in 90 sec with a 2 min rest, which is 3:45 per km pace. If I was to run much faster than this and add squats I would have needed a bucket. LOL
Big deal. Can you coach him to a 60 meter hammer throw?
Yes.
The problem arises when you use the word âsprint.â Sprint is often assumed that runners are running at their top speed throughout the entire distance once they attain it. How many years had I heard that a runnerâs âstartâ made the difference in the winner of the race?
If you have recently followed track & field on the international level, you have seen Noah Lyles appears to get faster every step he takes. He often looks like he is still accelerating the final 10 meters, passing a number of competitors.
Measuring technology now offers much more detailed analysis of the race. Analysis has shown that Noah Lyles is not accelerating in the final meters of the 100 meter run. The field is slowing down from their top end speed and that is in less than 100 meters.
The point is that most all the elite sprinters cannot run 100 meters at their top end speed. The 400 meter run is much easier to see that keeping top end speed is not a reasonable expectation.
After doing a hard set of squats, a run of any kind is out of the question. I do good to look like I know how to walk, and usually only to the nearest place to sit down.
If I recall correctly, Ben Johnsonâs coach said, âIt didnât happenâ.
Thatâs the benefit of working out at home. A comfortable chair is a mere feet away.
I think that was the main point of contention at the time of publication too.
Right. I searched for Charlie Francisâs interview on here from a long time ago in which I think he said that. I donât think itâs here anymore.