If you are convinced about incorporating High Intensity stuff in your exercise plan; let us look at ways to get a little uncomfortable,ways to crank up the first gear.
As I said earlier,when you are working harder,you will work for lesser time.Harder is whatever makes you gulp for air and sweat.It will be different things for different people.There are three easy ways to induct some Heavy Breathing in your Workouts :))
1Somewhat High Intensity Intervals (SHIT!) 7-8 on RPE.
Think of intervals as a way of inserting four-five peaks of action in your moderate exercise of the day.
Always Warm-up. Walk a bit,breathe deep,wiggle body parts that seem stiff;run or jump-forwards,backwards,side to side.Do this for ten minutes.
Choose an exercise that you can perform safely at a relatively high intensity. eg a stepper,stationery bike,rowing machine.Walking is fine for de-conditioned newbies.Walkers
can change gradient and speed of walking for 2-3 minutes.If you walk
you can incorporate some stair walks.For every ten minutes walk,do two
stair walks.If you jog you can incorporate four uphill intervals in a
twenty minute session.Sprint intervals are recommended for the better conditioned runners.
Go up to the level of intensity you can handle for 10 to 30 seconds. 90%
of maximal heart rate is considered to be a good goal for a healthy person.But you can initially just go harder than going all out.Just hard enough so that you can not talk while doing it.
Take it easy on your first few days,experiment,watch your body's reactions.Increase a bit,see how it goes.If you are comfortable handling it,try doing it for a minute or more.After figuring what you can do safely,you can push yourself four or five times in an exercise session .
Slow Down: In between the high intensity interludes, slack pace as much as you need to in order to recover for your next round.Beginners may need several minutes to recover. Others
may find less than one minute to be adequate.
Cool down: Stretch,roll on a tennis ball to soothe the muscle worked out and deep breathe.
You can use any exercise,or combination thereof, that you can safely handle.It can be walking and stairs;walking and uphill,walking and Burpees,walking and [push-ups,Dumbell swings,squat,kickboxing].It can be swimming sprints or backstroke with butterfly stroke.The possibilities are limitless.
See this Prevention Intervals Routine for step-by -step instructions;although I do not advise Sprinting for beginners.
2. Circuit training.
I always think of circuits as an Assembly line form of exercise -everything is done at a moderate pace for a moderate number of times ;but the quick transition from one move to other and rotation of muscles ensures that you get a bigger metabolic bang for your buck.
Circuit training involves selecting a set of 5-6 exercises which can include weighted exercises,or aerobic and bodyweight exercises in a nonstop fashion or with very brief rest;one after the other.Once the circuit is finished a rest pause of 3-4 minutes can be taken,before repeating the circuit again three or four times.For example:
30 jumps, a plank (30 secs),20 lunges,10 pushups and 10 medicine ball throws.Rest for three minutes,repeat again.You can do a walking-rowing-cycling circuit;make the circuit longer or shorter do it with lighter
weights, machines, your body weight, mix cardio exercises and
machines, mix cardio and weights, etc. The bottom line is that you
are providing some resistance to your muscles in a way that "feels" like a
cardio workout at some point.
Here is a great beginners link for fashioning your own Circuits.
Even more basic Prevention.com Circuit Training for Beginners.
(The rules of warm-up by light jumping,jogging wiggling etc apply as does the cool-down stretching.)
3.Cross Training .
This is about mixing it up to have an appetizing salsa of activities to choose from.Your goal is not to be a pro,but to take benefit of sports and physical activities across the spectrum.Cross training is a principle of training athletes for optimum injury-free performance;but the wisdom of it applies to us weekend warriors as well.Incorporating several modes of training like strength training,balance training,general conditioning ,martial arts moves into your exercise programme helps you in recruiting different unused body-parts (muscles),in strengthening weak muscles and in preventing injuries from repetitive strain.It helps by giving the overused parts a rest,strengthening compensating muscles and in countering the Adaptogenic effect of exercise.
You can think of it as having a stocking full of exercise gifts to choose from and going in for what suits your body and your mood that day.Some days Boxing feels like therapy;other days a long leisurely bike ride is elixir;some days you want the Heavy Iron and on other you look the other way if anyone says deadlift.Include some activities you genuinely enjoy here,but also attempt to learn new stuff.It keeps you from getting bored and makes for safe and enjoyable exercise.