By Devon Jones, NSCA CSCS-CPT , ACSM HFI, B.A. Philosophy
For over a century, it has been known that productivity drops after 40 hours per week. This fact motivated Henry Ford to change to an 8 hour shift as opposed to the customary 10 hour one. After 2-3 hours of consecutive work, focus drops, and more mistakes are made. More time spent working can actually perpetuate itself if extra time is spent correcting those mistakes. Well, the same thing is true of exercise and fitness! For exercise to build itself up to actual fitness, high intensities need to be maintained. Exercise sessions longer than an hour often lack the sustained intensity needed to build fitness. Even worse, they can lead to burnout and overtraining. This leads to either injuries or a lack of consistency in training. Either way, those long exercise sessions fail to build fitness and health, and can become a waste of time. For this reason, the mid-day workout can be the solution to that constant problem of balancing exercise with other obligations like work and family. By exercising mid-day, you give your body a mental break from work. You are also forced to manage your time in order to workout effectively and at the appropriate intensity. All of these things help you to continue exercising consistently, and it is through consistent, sustained effort that the best results are seen.
A quick look at exercise physiology helps can help to illustrate why long workouts are often not as effective as shorter, more challenging ones. After about 45 minutes to an hour, the body's stores of glycogen, of blood sugar, are depleted. Exercise intensities of 80% of maximum and above rely more upon glycogen than oxygen. Weight training primarily relies upon glycogen, not oxygen, and even hard aerobic exercise relies upon glycogen to a high degree. For exercise modes like interval training and higher sustained heart rate work, oxygen can no longer provide the energy needed to run, bike or swim at a faster pace. It is often this faster pace and these higher heart rates that are needed to bring about the cardiovascular adaptations need to help the heart and lungs move blood and oxygen to the muscles more efficiently, and to allow the muscle to effectively use the surplus of oxygen. Without the ability to use more oxygen, the body cannot work at higher paces and burn more calories. It is for this reason that weight loss often stagnates later in a program, the body fails to exercise at the appropriate intensity. Not all work should be done at high intensities, but it is a necessary part of an exercise program once basic conditioning is reached. Shorter, harder workouts allow the body to work hard enough to improve, but are not so long that exhaustion, overtraining and injury result.
These short workouts also mean that a day does not need to be structured around exercise. This is not to say that long, sustained, moderate to low intensity aerobic workouts aren't sometimes useful. Sport and training goals may also require longer workouts to build the skills and specific conditioning needed for a long distance race or to improve one's tennis game. However, for general conditioning, health and fitness, 5 hours a week properly spent can be of great benefit, and can fit within even busy schedules. The middle of the day is a perfect time to fit in a 4 mile run, a quick weight training session, or even a rejuvenating yoga class. A short hard workout exercises the body without exhausting it. Reenergized, the body and mind can work more effectively and efficiently. The piece of mind that comes from a finished workout can be contrasted with the worry over deciding where fit in a workout, of worrying whether work or family time will be compromised to fit that workout in.
Like any new routine, time must be budgeted to fit workouts in, but by keeping in mind that less can be more, exercise can be done quickly during the middle of the day as an enjoyable escape from work and family obligations. Who knows? Perhaps this lesson begins to be applied at work as well. Work gets done efficiently, without extra time being spent correcting mistakes or moving in circles. This leaves more time to focus on health, hobbies, and family…which are the primary motivators for your career in the first place.
