If you do a hard workout on Tuesday, when should you do the next one?
Where you place each workout in a training program matters. If you do a hard workout when your body is still in a state of shock from the initial stressor, greater fatigue will result, and it will take longer to recover. If you keep doing workouts before you fully recover, you’ll end up in a chronic state of under-recovery, and your performance will spiral downward. If, however, you do workouts at the most optimal time following the recovery from the initial stressor, when your body is over(super)compensating, your fitness will spiral upward, and your performance will improve.
The most optimal training program — the one that is going to make you run faster with less risk for injury — includes a correctly timed alternation between stress and recovery. I have coached runners who can do hard workouts every 48 hours, and I have coached runners who can handle only 1 hard workout each week. The runners in Kenya where I am now run 2 hard workouts each week, with those 2 workouts separated by 48 hours.
How do you know what the ideal time is between hard workouts? There’s a way to know, but that way requires extensive blood work to examine markers of stress and inflammation and a muscle biopsy to assess the degree of muscle fiber damage. The other way to know is through many months and years of trial and error. (This is why when a coach proclaims that his/her training is “customized” or “individualized,” that’s not true. There’s no way for a coach to individualize the training for you until he/she has coached you for many months to years and pays close attention to how you’re responding to the training.)
Want to learn more? Pick up a copy of Running Periodization.