This saying applies to many aspects of training and exercise.
For example:
1) Training hard 3 times a week for an hour at a time has greater benefit than training half-heartedly 5 times a week for two hours a time.
2) Lifting weights with correct technique and completing 8 good quality reps with full R.O.M (Range of Movement) is much more effective than doing 15 poor quality half reps.
3) Don’t lift more weight than you can mange. Lifting a weight that is challenging but manageable for your desired number of reps is more effective than going too heavy and either not completing the set or completing it with bad form.
At Arena Health and Fitness UK we teach how to exercise properly and effectively. Train hard and train smart. Using a well designed programme and correct technique will bring you optimum results.
Keep up the good work!