Research has shown that you expend more energy with novel tasks.  As time goes on and your body becomes accustom to the exercise and you expend less energy because you recruit more motor units.  When you walk backwards, you strengthen the quadriceps muscles and develop more power in them.  At the same time, walking backwards minimizes the patellofemoral joint reaction forces.  The knee flexion increases in elevation when you walk backwards.  This was discovered by physical therapists and is today a great rehabilitation technique.  In addition, it was discovered that backward locomotion increases the energy expenditure along with the metabolic cost and cardiopulmonary demand as compared with walking forwards.  What this means is walking backwards can not only allow athletes with knee problems or those who are in  post rehabilitation from an anterior cruciate ligament reconstruction to exercise...it may also increase aerobic fitness.  Walking backwards requires oxygen uptake (Vo2) at levels that can produce a cardiovascular training effect.  In conclusion, efficiency increases when a particular task is no longer novel, as the body recruits motor units more efficiently.  The athlete can now increase the speed of backward locomotion to maintain the energy expenditure.  

SIMPLY PUT, WALK BACKWARDS IF YOU HAVE KNEE PROBLEMS AND OR YOU WANT T0 GET IN SHAPE FASTER THAN JUST WALKING FORWARDS.  YOU CAN ALSO RUN  BACKWARDS, OR MIX YOUR RUNNING WITH FORWARDS, BACKWARDS AND EVEN SIDEWAYS LOCOMOTION.

Here is a great workout that Spindel Sports Academy implements with High School athletes.  It can be conducted at the beach while running on the sand barefoot, on a treadmill with level and  incline positions or at the park. 

Warm-Up  (5 Minutes)

“Slow run” on hard sand close to the water.

 Phase I  (5 Minutes)

“Performing laps.”  Take 25 steps at medium speed in softer sand away from the water.  Move in 2 directions, 25 steps north, turn around and take 25 steps south.

Phase II  (10 Minutes)

“Circuit run.”  Take 10 steps at medium speed in very soft sand far away from the water.  Move in 4 directions, 10 steps forwards, cut 90% and take 10 steps sideways, cut 90% and take 10 steps backwards, cut 90% and take 10 steps sideways.

Phase III  (5 Minutes) 

“Explosive.”  Take 6 steps forwards at full speed and stop.  Each 6 steps are considered one repetition.  Rest for 10-15 seconds between reps. Repeat for 5 minutes.

Phase IV  (5 Minutes)