Many people are still unaware that results in fitness and fat loss require a push that forces the body to respond. If you’re sitting in a coffee shop and someone slowly walks up, gently taps you on the shoulder and whispers fire, you’re going to behave very differently than if someone screams FIRE at the top of their lungs and sprints towards the door. This is what it is like in fitness. In fitness the thing that gets you moving toward the door is anaerobic effort.
Going anaerobic means you have just turbo-kicked the aerobic zone and gone into super-drive. When you do this you have effectively grabbed your physiology by the shirt collar and jacked it up against the wall. It has no choice but to respond. The only problem is this type of effort is uncomfortable. It is like putting your hand on a hot stove. People don’t want to go there, and it is virtually impossible to stay there. Unless of course you know the tricks of fatigue management.
Rest and results
Rest is perhaps the most important tool in fatigue management. Continued work without rest will inevitably lead to regulating intensity in a way that does not deliver optimal results. A quick glance at the emerging research shows continuous moderate intensity exercise proves ineffective for weight loss or metabolic adaptation.
Miller et. al. in the International Journal of Obesity in 2007 (Vol 37 # 2) reviewed hundreds of studies over a period of twenty plus years. The consensus was continuous moderate intensity exercise had no real weight loss advantage over diet alone. More recent research by Melanson et. al. in the journal Exercise and Sport Sciences Reviews (2009;37(2)) showed moderate intensity continuous exercise produced no metabolic advantage.
Yet, when rest is factored into the equation intensity can be elevated and results begin to emerge. Trapp et. al in the April 2008 issue of International Journal of Obesity compared standard aerobic exercise to intermittent cardiovascular exercise using rest. After 15 weeks the interval training group lost close to 3% bodyfat while the standard aerobic group actually gained just over .5% bodyfat. This was despite a workout that was a full 20 minutes shorter (20 min vs 40 min) for the group using rest intervals.
Rest also has benefits on getting more muscle fibers activated which is a key factor in forcing the body to respond and adapt to exercise. The February 2004 issue of the International Journal of Sports Medicine showed four weeks of sprint training increased the ability to generate more muscle fiber activity compared to standard aerobic exercise. Sprint training is impossible without rest between bouts.
Another article from the November 2007 issue of the Journal of Applied physiology showed fast twitch fibers are rarely engaged to any significant degree in slow continuous exercise. And, when looking at weight training, brief rest periods have been shown to have a greater impact on muscle stimulation compared to little or no rest (European Journal of Physiology.Aug 2004 Vol 92).
The psychology of rest
Going back to our stove analogy, leaving your hand on a hot stove is something most would decline outright. However, if you were able to touch the stove quickly and immediately remove your hand, you could not only tolerate the stove, but likely do no damage thus accomplishing a task you would otherwise be unable or unwilling to do.
Taking rest within an intense workout allows short-lived discomfort that will give you the results you want without going overboard. This strategy has been employed successfully in interval training and is exactly the reason it is so effective. Interval training is not possible without rest.
But, what if instead of saying you need to workout for a set time and then rest for a set time, we instead told you we want you to work and rest within your own limits? Would exercisers workout harder, or would they simply take it easy? A study in the September 2005 issue of Medicine and Science in Sport and Exercise looked at the effect rest-duartion had on self-selected intensity levels during intense interval training. The study determined that when rest periods were defined for exercise participants, a 2-minute rest compared to a 1 or 4 minute rest length, created “appropriate balance between intracellular restitution and maintenance of high VO(2) on-kinetics.”
In layman terms, 2-minutes was the optimal intensity for results. Interestingly, when subjects were allowed to self-select their rest period without any knowledge of time, they “chose” rest period lengths that settle at around 118 seconds, virtually identical to what researchers defined as the optimal work to rest ratio. This opens up interesting questions about the benefits of defined work and rest protocols over self-selected exercise. Perhaps we humans have a built in fatigue management sensor allowing us to regulate our own exercise intensity?
Studies in animals also argue for a fatigue management strategy in our physiology. It appears humans are not alone in the ability to self-regulate exercise to optimize intensity and recovery. In 2009 (volume 39 # 10) of the journal Sports Medicine, a review by Dr. Ekkekakis highlighted research showing many animals adapt intermittent patterns of movement to maximize work and rest. It is speculated that this pattern of movement is an evolutionary adaptation allowing animals to cover more ground and longer distances.
Rest-based training, the fatigue management system
Rest-based training is fatigue management at its best. With rest-based training rest is embraced as the primary goal in exercise. You work until you feel a rest is needed, and then you start again as soon as your ready. Weight lifters, bodybuilders, and interval users have always exploited rest to maximize work. Adopting a rest-based approach means throwing the old defined rest periods away and instead allowing rest between sets, within sets, and whenever necessary to maximize sets, reps, and work intervals. In this way, the work done can be maximized while recovery enhanced, and the exerciser gets more work done with less time invested.
Final thoughts
Results in fitness and fat loss come down to one thing, quality work. This is a universal principle. You don’t get a trophy simply for showing up. The effort you put in is what makes the difference. Therein lies the problem. There is a fine line between doing enough and doing too much. Increasing effort is usually taken to mean do more, but the most successful in any endeavor usually find a smarter way and maximize quality over quantity. This concept can be used in fitness through fatigue management workouts.
