A departure from the usual Cheery Beggar topics . . .
I love to run, and I love and hate (but mostly love) a workout called “40/20s.” It’s the quickest way I know to get in shape, you can do it no matter your current fitness level, and it’s low impact so unlikely to give you over-use injuries like shin-splints.
What you do:
Get a stopwatch. Find some open grass like a soccer field. Jog easy for 10 minutes to warm up. Cross the field as you do this to check for holes, roots, etc. so you can avoid them later on—the workout will be done across the length of the field.
When you’re ready to start, sprint across the field for 40 seconds. Don’t run all-out; go as fast as you can while still feeling under control. Try to run at about 80-90% of your max.
When your watch hits 40 seconds, stop and jog easy in place for 20 seconds. You’ve now completed one set, and it takes exactly 1 minute. Then turn and repeat this for a total of 15 sets—it’ll take you 15 minutes.
After you finish, walk/jog for at least 10 minutes to cool down. With a 10 minute warm-up and cool-down, the whole workout takes just 35 minutes.
Why it works:
When you exercise, your body uses oxygen to break down fat into energy for your muscles. This is called “aerobic” exercise because it all happens “with air” or oxygen.
As you increase the intensity of your exercise, your body struggles to keep up with the increasing energy/oxygen demands of your muscles. At some point, your body starts using an “anaerobic” (“without air”) process to generate the extra energy needed. This process involves breaking down glycogen into glucose. It’s awesome, but it also produces a by-product called lactic acid. The burning sensation you get in your muscles and the Jello feeling you get in your limbs is caused by lactic acid buildup.
The neat thing is you can train your body to do more while remaining at an aerobic level, and you can also train your body to better handle and push through the feeling of lactic acid buildup when you do switch over to anaerobic activity. You can do this by training at your anaerobic threshold level—right at that point where you start to experience the burning Jello feeling.
The 40/20s workout is designed to get you working at your threshold level. Quick, high energy demands like sprinting send your body into anaerobic-energy creation mode right away. The short rests (only half as long as the sprints) prevent your body from catching up with oxygen and keep you at that threshold level. Basically, you’re getting a big bang for your 15 bucks. And if you run on grass, you won’t be pounding your body on unforgiving concrete.
Try this workout and you’ll experience that time really is relative. Those 20 second rests pass in a flash, and the 40 seconds of sprinting—especially around sets 10-15—can last for ages.
Post-workout always reminds me of this line from C.S. Lewis’s Problem of Pain:
“. . . and, if I may trust my own feeling, a slight aching in the legs as we climb into bed after a good day’s walking is, in fact, pleasurable.”
This workout will mess with your mind. Especially when the lactic acid kicks in, you’ll be very tempted to slow down a little and take a little longer rest. But if you just grit your teeth and stick it out for 15 minutes, you’ll find the physical and mental rewards are pretty great.
Do this once a week, DO NOT skip the cool down, and in two to three weeks you’ll notice a big difference.