I finished Month One of Insanity’s 60-day total-body training program after starting the first week of January. I came at it with a view to improving my cardiovascular fitness and running performance, not for fat loss. I was also looking for a session that makes me feel that I got as good a workout at home as I do in a group exercise class at my fitness club. But I got a lot more than that.

What is it?

If you’re looking for an at-home extreme workout that pushes your athletic potential, this is what you’ll have in mind. Many of us depend upon a coach, trainer or instructor to get our fitness fix because the reality is few of us can push ourselves during extreme workouts. But I have a solution.

Try Insanity from Beachbody. What they created is stunning. You alternate between explosive cardio drills, power and resistance moves, core and balance exercises. What’s different about Insanity from other extreme workouts is intensity.

The concept is lifted from interval training and then for that extra something, it’s supercharged, so you perform Max Intervals. Generally, you might work out at a moderate level, let’s say on a treadmill at 6 miles an hour, then spike the speed up to 8 miles an hour for 30 seconds to a minute, come back down, and then repeat.

However, Shaun T [for Thompson], Insanity’s creator and instructor says rhetorically, “But why not run at 10 miles an hour for two minutes, rest for 30 seconds, and then run again for that long through the 40 minutes, so you get the max cardio burn and endurance level, making you fitter.”

And because of Max Interval training he’s teaching you to breakthrough your fitness threshold — or dig deeper — and it seems Beachbody has too.

How good is the production quality?

Insanity is a 2010 Beachbody release marketed in the spirit of P90X. Beachbody shows off sensible productions values on the set, putting money into filming, cast and rugged packaging. They haven’t skimped on quality. The cover of the hefty basic DVD set shows Mr. Thompson and his group class reflected in a pool of sweat. Open the case and a high school gym sets the scene, which may recall good or bad memories of your early Phys. Ed. days. All of this impressively says that Beachbody’s put the focus on performance. Few DVDs do.

Much of the workout is filmed in high-definition framed in a straight shot, with overhead angles cut in. I love the intimate moments where Mr. Thompson kneels next to a cast member to offer form advice or encouragement.  You can also navigate through the entire set easily because it has a menu.

Meet Shaun T

I want to talk more about Insanity’s instructor, though. Mr. Thompson is an immediately likeable muscular fitness leader. He’s a big guy. He has a friendly personality without the ‘You go girl’ goofball banter. And you feel healthier just watching him and his high-visibility abs. This is essential when committing to a DVD because your personalities have to click. Otherwise  you won’t do the workout.

Throughout the DVDs, you do get a sense that the 32-year-old New York-based madman encourages you because he genuinely knows it’s a tough workout (tough enough that he missed repeating a stretch move on the opposite side in the second DVD). And he’s sincere in offering you the best workout he could create.

“It’s designed so you feel like an elite athlete. The goal is cardio endurance or strength. Some people just like to lose weight and some people put on muscle because of the way I designed the nutrition guide,” Mr. Thompson says.

You can gain, maintain, or lose weight depending upon how you eat, Mr. Thompson adds. He claims some people put on 15 pounds of muscle just by using their own body weight as resistance and following his nutrition plan matched to a goal. Of course, motivation influences success, too.

Does it motivate?

As I previewed the series before exercise, Mr. Thompson’s incessant talk and breathlessness grated, but chatty instructors annoy me. Then during the workout when it truly counts, I couldn’t hear him talking because my heartbeat was deafening. My ears became finely tuned to any word from him to guide me through. You know, when you’re mind thinks it can get knees to hip level, but your body is saying ‘Nah uh, not today, Sugar’. In comes his Will Smith-sounding voice talking as if he’s got your back and that’s pleasingly reassuring.  You never once get the impression the workout exists to pump up his ego. I love that he doesn’t pronounce Ts.  A warm–up is not important, it’s “impor’n.”

“I offer motivation and safety cues throughout the workout, and then when you’re reaching that point where you can’t go anymore, I say ‘C’mon, guys, just push and you can do it.’” And what you do is your best that day.

What do you get?

Along with effective motivational value, for $120 you get 10 high-quality DVDs, (11 if you purchase Insanity here at www.pledgetostayfit.com). Month One introduces aerobic and anaerobic intervals designed to build your fitness base in six, 40-minute workouts. Month Two applies Max Interval circuits in four, 50- to 60-minute workouts. Mr. Thompson says, “Here the interval are longer, the rest are the same, and there’s a recovery week in the middle of this month that prepares your brain and body for what’s about to happen.”

A nutrition guide outlines your diet for 60 days, so you can accelerate your results by feeding your muscles, while burning fat. Online support where you can get help or socialize is available at no charge, 24/7.

A motivational wall calendar allows you to track your progress so you can check off workouts you’ve completed — or tried to — along with your Fit Test results, which are humbling. In future editions, the producers should provide buckets and towels because you will sweat. Oh, you will sweat lushly. You may be thinking, as I did, that the pools of sweat on the packaging was hype. But you’d be wrong.

What’s the secret appeal?

The secret of Insanity is simple moves at super speed. What Beachbody does is take intervals and make them longer and shorten the rests. There are familiar moves from popular DVDs without choreography. That’s appealing to men who don’t want to sashay around the house.

“No grapevines,” he laughs. “Oh my gosh, I tell people there’s no beat to stay to. I give you the move, there’s a 30-second rest, now go. And every time you do it you get better without doing pirouettes.” Mr. Thompson says.

“I wanted people to get that runner’s body and feel how I feel at my elite training when I was super, super, fit, so I designed the workout to give you the benefit of both things.”

He says he picked plyometrics for two reasons: explosive movements work fast twich muscle fibers so that helps you gain speed. And the range of motion that you get from plyometrics is effective.

“When you go into a squat you work hamstrings and butt, and then at the top of movement you work quadriceps. These are compound movements. It’s the same thing with floor runs and push-ups.”

What are sessions like?

You don’t ease into Insanity, you‘re fired out of a cannon. In the first month, I was in pre-conditioning mode, which felt like a training camp leading up to the big leagues. Before I could see progress, I could feel progress in my core, bending to pick up something the day after a workout. I could directly link that zipped up tummy to Insanity.

If you move fast enough, you can do 157 Power Kicks or 83 Power Knees or 25 Suicide Jumps in a minute. You can be fast on a new level and it can make you feel like Kobe Bryant has your heart, handling it as if he were double dripping a basketball. It’s unbelievable red-faced hard work.

Who’s it for?

Doing the drills, I worked myself into a panic; every alarm in my body sounded at the same time. It’s that feeling of flying around a hairpin turn in a race car when suddenly the wheels lift off. It’s thrilling because you seem out of control. Insanity is for people who consider going to that edge is fun. Of course, such intensity is pointless after 30 minutes because health benefits are achieved. But the heart-pumping fits of mania is the reason Insanity is such a high. That’s where the addiction comes from. I developed a dependency on the self-pride you build doing simple moves at a difficult level. Knowing that high is on demand when you press play creates a healthy habit.

Anyone who wants to know how fitness madness feels should do one of these workouts. Nothing on DVD is harder.

Even the crew, with heaving chests and floppy limbs, grunt when they have nothing left to give. Or they pause in mid-workout to regain steam. I love this because it’s what happens in gym classes. I’ve done four infomercials as a supporting fitness model, so I appreciate how the cast endured the workouts so producers could make the shots. And from this insider perspective, Insanity is mindblowingly fierce. Frequently Mr. Thompson reminds you to exercise to tolerance. And you have to bite down, growl, hoot and holler — do whatever it takes to break through the threshold and get past your current limitations so you can move onto your next fitness level. I’m a dig deeper gal, and I applaud the ones who can go without slowing the pace. This is lunacy.

What body part got the strongest?

By the time I finished Month One I needed my fix, my body craved it. I was exhausted during the peak part of the workout, but felt energized afterward. My co-ordination and running speed improved, in part due to a stronger core and faster leg turnover speed felt in my run — even doing Insanity at half intensity. I never made it though one workout at the same speed as Shaun T, but his ability serves as a goal. I feel like I can conquer anything. Over the years I’ve done spinning,  Navy Seals workouts and a half marathon, but for sheer excitement Insanity is off the scales.

Can home workouts give you a better workout than gym classes?

Still some people may say exercising at home is never as energizing as a group class at a gym. Please. You get the vibe. You feel the exercises working. You can make them livelier by adding the music track. You earn a satisfying sweat.

There are other intense workouts, for sure, but not on DVD. Beachbody made their cardio offering better by focusing on intervals, and then made a monster. The warning label that comes with it seemed like a marketing gimmick. It is. And it’s not.

What doesn’t it work?

But it has to be said: There are no modifications, no on-screen calorie burning clock, no measurements to report of inches lost or gained, and little upper body development except for push-ups. There is no spot toning for those looking to just get rid of a big belly. There are no chin–ups, no weights, no military presses, no rows. For a convenient home workout this is no problem. How can you go wrong with a workout that requires no equipment?

Well, you can. There’s not enough biceps, triceps and shoulder building exercises that Insanity could replace my strength workouts. For that you can order Insanity’s deluxe version with upper-body toning workouts.

How do you measure your progress?

The interesting thing is knowing when you’re fit. You do the fit test every few weeks and once you see the numbers go up, you know you’re becoming fitter because you can do more repetitions of the exercises.

“A lot of people when they start out can’t do a full push-up, so it’s amazing after 60 days seeing people banging out 15 Push-up Jacks,” says Mr. Thompson, whose personal workouts are similar to Insanity, but also include weight training, dancing and running three times a week.

What’s next after you survive Insanity?

“In the next couple months I will release Insanity The Asylum: Volume 1, Sport Performance. It’s the next level after Insanity and it’s geared toward helping you become a better athlete,” Mr. Thompson says.

To football and rock climbing to tennis and baseball, the new series will also include strength training, speed and agility, vertical jumps to leap higher, stretch, and Game Day with a special Overtime when you want to do even more. Runners can boost endurance and sprinters can rocket off the starting blocks.

Meanwhile, I have to get through Month Two.

Sign-me up?

So, as a low-impact workout with modifications, Insanity’s not good. Instead, do any DVD from Beachbody, which is less high-impact, less intense and less of a workout.

Insanity keeps its promise of being the hardest workout on DVD. The fact that progression is integrated into the track and field-based workout means you have a DVD set that will remain relevant for years.

If you want a group exercise experience with a likeable, motivating instructor, teaching challenging routines with enough variety to keep your mind on point and your body glistening in sweat while working out with a dedicated crew plus the ability to jump online to track sessions and socialize with others, and if you’re insane — here’s your workout.

By Monique Savin