What is the law of diminishing returns? It has its origins in economics but can be applied to many other areas in life. It can typically be explained as "too much is not necessarily a good thing."
Whether it is eating an entire pizza or a dozen doughnuts, or doubling or tripling your normal workout repetitions, running miles or training time, this type of poor judgment inevitably reduces your productivity.
Whether the result is an upset stomach, unwanted weight gain or the aches and pains of overuse injuries, the law of diminishing returns will apply in every activity that we overdo.
Do you know why 30-day fitness challenges are so hard to complete? If these challenges include harder workouts, running miles and more strict eating guidelines than you normally do, you may see counterproductive results.
The challenge is more of a gut check of your discipline than anything else, but there is a fine line between mentally tough and stupid. Anytime you take a fitness challenge that is relatively extreme compared to your current workouts and fitness level, you are risking sidelining injuries that could set you back for months.
If you do get an injury that sets you back for months during a 30-day fitness challenge, you are the personification of the law of diminishing returns. You have just proven the fact that the more you do something to an extreme, the fewer results you get from it.
Besides, the term "extreme" is relative. For an advanced-level exerciser, doing 100 pull-ups in a workout is not a problem. However, for a beginner, doing just one might be impossible.
Be careful what challenges you select for yourself. Here are some ideal ways to challenge yourself and a few options to attempt only if your current level of training supports the effort.
30 for 30
Walk 30 minutes a day for 30 days. This challenge is simple by design, but challenging enough for people who do not walk regularly and need to lose weight or get into better aerobic condition. Some people may take this one and change it to biking or running.
If you do choose running, make sure you assess yourself first. If you already run several days a week, adding more may not be too bad for you. But, once again, running overuse injuries tend to occur when jumping to a higher number of miles per week that is outside what we'd consider a normal 10-15% miles or time per week progression.
Another 30 for 30
Pick a few exercises and do 30 repetitions of that exercise. These can be calisthenics like push-ups, squats, plank pose for 30 seconds, pull-ups, lunges or dumbbell exercises.
If you are doing a resistance exercise challenge, I would recommend making an odd/even day series for the upper body exercises and the lower body exercises. This way, you can recover from the movements if you are not used to doing these exercises or used to this kind of volume. This is a great challenge for beginner and intermediate levels of activity.
30-Day Advanced Challenges
Some more advanced exercisers may challenge themselves by doing staggering amounts of repetitions and/or mileage each day. Once again, these are relative and should not be taken on by beginners, intermediate and even some advanced athletes.
WARNING: If you are not used to the following volume of repetitions and mileage, then do not try these challenges or at least assess yourself and drop the reps or miles to something that is more suited for you.
1,000 Push-Ups a Day
Doing any one exercise for 1,000 reps is not a good idea. Yes, it is a gut check and tough mentally due to the pain of failing repetition, but if done for 30 days in a row, you will lead to overuse injuries in your joints (wrists, elbows, shoulders) and likely develop some severe muscle imbalances in your arms and between the front and back of your upper torso.
These can inevitably lead to pain and injury for long periods of time as well. My advice is to take an average of the amount of push-ups you do each week. Maybe normal workouts total 200 a day for three days a week (every other day).
If you've been doing 600 push-ups in a week and then jump to 1,000 push-ups a day -- well -- do I even need to say it? Regardless of how many you choose to do for your challenge, balance out all that pushing with an equal and opposite pulling exercise like rows, reverse push-ups, birds or arm haulers as in the PT Reset exercises.
1 Murph a Day for 30 Days
(100 pullups, 200 push-ups, 300 squats, Run 2 miles) -- The Murph is a fun challenge that I personally like to do once a month and especially on Memorial Day with a group of veteran friends. Doing this daily for 30 days will be tough mentally and physically. There have been success stories from this challenge, but there have also been countless knee, elbow and shoulder overuse injuries because participants were not even close to prepared for this gut check of a challenge.
If you do not run 15-16 miles a week already, don't jump into a month of 14 miles a week of running. If you do not normally do 100 pull-ups and 200 push-ups in upper body day workouts already, don't start with daily versions of that.
Every day is NOT leg day, so 300 reps of squats can lead to long-term, delayed-onset muscle soreness if you are not accustomed to that kind of volume in your workouts. FYI: Most people are not.
This kind of volume requires recovery days in between -- PERIOD. The young may have a quicker recovery time, but they typically lack the athletic history to be used to this volume and therefore are highly susceptible for the kind of injuries that will require months of recovery.
Once again, 30 days of challenges that cause months of inactivity and recovery time is the law of diminishing returns applied to fitness training. Make your challenges fun and not daily gut checks, and you will get more out of them.