If your inner thighs, quads and glutes are experiencing the delicate kiss of fitness today, here’s a basic explanation of why:
Take the load you lifted in Friday’s workout for the squat. Multiply that number by 45 reps. Then look at the total time it took you to do those reps, plus 45 kettlebell swings.
100-lb. squats x 45 reps = 4,500 lb.
35-lb. KB swings x 45 reps = 1,575 lb.
Total volume: 6,075 lb.
Time: 5 minutes or 300 seconds – or one rep every 3 seconds (on average).
That means you moved about 6,000 lb. of metal in about 5 minutes.
Compare that to Monday’s heavy squat workout if you did it: 5 sets of 5 squats.
160 x 5 x 5 = 4,000 lb.
Time: Approximately 20 minutes or 1,200 seconds – or one rep every every 48 seconds.
In this example, you obviously didn’t do 1 squat every 48 seconds. You did 5 in about 30 seconds, then rested for about 4 or 5 minutes. But you get the point.
The takeaway is this:
Strength workouts are hard because they are heavy, but you have to rest between sets because the load is so large. Rest lowers the average intensity of the workout, even if rep 5 of set 5 feels pretty damn intense. You can be sore after this workout because you are moving very heavy loads that test the limits of your strength and you often run up quite a bit of volume in a heavy 5 x 5 workout.
But short periods of max exertion produce a different training adaptation than if you squat medium loads very quickly. In a conditioning workout where the intensity is very high, you aren’t testing max strength, but you’re moving a relatively large load a long distance very quickly. That challenges muscular endurance and different energy systems, and it produces a completely different training effect.
It can also produce some pretty noticeable soreness even if you only squatted a weight you considered “light.” It was light. But you squatted it 45 times really fast.
So when you sit down today and your legs start to scream, pull out a calculator, do some math and discover that you have been visited by volume and intensity. They’re good friends, and they’ll be back regularly.