Sometimes a little bit of a bad thing can be a good thing.听This phenomenon, known as hormesis, is what happens when a chemical agent or environmental factor that is damaging at high doses yields a positive effect when used in smaller quantities. Perhaps the most common example is vaccinations. Inject a tiny bit or weakened form of a toxin, and your body will build up resistance to that thing. Expose yourself to too much, and you鈥檒l probably get sick.听Athletes have been using this strategy听for years, but only recently have scientists started exploring how hormesis can be best听used in the context of fitness.听
This past May, researchers published a paper in the听Journal of Applied Physiology听迟颈迟濒别诲听鈥溾 They听evaluated听hormesis training strategies听and found that some can be quite beneficial,听but the听fine line between too much and too little is still being explored, and similar to other hormesis strategies, if done improperly, it can cause injury and illness. 听
Here鈥檚 what we know so far:
Low-Carb Workouts
What It听Is:听Exercising without carbohydrates stored in the body or ingested during training, sometimes referred to as 鈥渟tarvation workouts,鈥 can improve the body鈥檚 ability to store glycogen (the stuff that powers intense activity, which, ironically, is made from carbohydrates) and use fat for fuel. 听Starvation workouts have also been shown to increase activity in mitochondria, the part of the muscle cell听that generates energy. 鈥淐ollectively, these findings suggest that manipulating carbohydrate availability before and/or during exercise stimulates several of the metabolic and molecular responses that promote adaptations to training,鈥 wrote the study鈥檚听authors.听
The easiest way to prepare for a low-carb training session is either to eat a low-carb dinner and train before breakfast听or to perform two workouts in the same day (e.g., morning and afternoon) without ingesting carbohydrates in between.
How to Do It:听, a听physiologist, founder of , and coach of world-champion triathletes, says athletes should keep low-carb sessions at lower intensity and refuel immediately following the workout.听Moreover, these workouts should be executed infrequently (such as once or twice听a month)听and when the athlete has limited stress beyond his or her training鈥攔est must be prioritized after these sessions. It鈥檚 also important to note that a low-carb workout听does not mean a low-carb diet, something sports nutritionist Matt Fitzgerald told us in an article published in February.听
Dixon believes that 鈥渂efore an athlete should even begin playing with this type of thing, they need to establish great baseline habits听and a nonemotional relationship with eating and fueling.鈥澨鼿e warns听that this sort of approach is often a slippery slope to ongoing caloric restriction, something that 鈥渃ertainly yields negative results.鈥澨 听听
Inflammation

What It Is:听Quick word association test鈥攚hen I say 鈥渋nflammation,鈥 what comes to mind? Go.听
Perhaps you came up with 鈥渂ad,鈥 or 鈥減ain,鈥 or 鈥渋buprofen.鈥 You probably did not think 鈥渟tronger鈥 or 鈥渞epair.鈥
It turns out that a little inflammation is both completely normal after a hard workout and helps the body adapt to exercise. Additionally, the Applied Physiology paper found evidence that taking nonsteroidal anti-inflammatory drugs听(like ibuprofen)听diminishes exercise adaptation and recovery by inhibiting pathways that increase blood flow to the muscles. 听suggests NSAIDs may slow bone remodeling and healing.听
Which makes us ask: Should we lay off the vitamin I?听
Yes and no, according to , a sports medicine physician in Santa Rosa, California. While some inflammation is beneficial, chronic inflammation can cause pain and mobility loss that prevents athletes from training. It may also directly contribute to muscle wasting.听鈥淭he key is to use NSAIDs appropriately,鈥 says Weitzenberg. 听
How to Do It:听A good rule of thumb is to never take them prophylactically (that is, before a workout听to make听it听hurt less) or for typical post-training soreness. Not only does this lessen fitness adaptations, but it also poses a risk of GI bleeding and kidney damage. 鈥淚鈥檓 amazed by how many people take NSAIDs as a 鈥榩reventative鈥 measure,鈥 says Weitzenberg. 鈥淎dults even do this with their kids. It鈥檚 so bad鈥攁nd shocking, really.鈥
Dixon鈥檚 rule with the athletes he coaches is simple: 鈥淲e tend not to mess with inflammation, especially post-workout.鈥澨
In other words, only in very specific cases should you turn to NSAIDs. For instance, if you suffered an acute injury with severe pain and swelling or have an overuse injury that isn鈥檛 resolving on its own, then taking NSAIDs as recommended by your physician is not a bad idea, according to Weitzenberg.听鈥淭here is a time and place for NSAIDs,鈥 he says. Just be sure to rule out bone injuries like stress fractures, since NSAIDs can delay the healing process.
Preloading
鈥
What It Is:听Training hard when you are already fatigued is no fun.听However, when done at the right time and dose, the effects are powerful. According to , a physiologist at the University of Kent, training on tired muscles doesn鈥檛 just improve physical fitness, it also听improves mental fitness. Preloaded workouts overload the body and mind, forcing both to work harder and get stronger. As discomfort and deep fatigue set in, the mind wants to quit, but in essence you are making it 鈥渃hoose鈥 to tell the muscles to fire, says Marcora, building up the mental muscle. And much like a stronger body, a stronger brain allows an athlete to tolerate more effort and push harder.听
, coach of world-class triathletes and runners and founder of QT2Systems, says the ability to perform with fatigued muscles, or what he calls 鈥渄urability,鈥 is vital to success in most endurance sports. 鈥淭raining under fatigue will likely improve the ability to perform under fatigue,鈥 he says. 听
How to Do It:听There are many ways to go about preloading. Examples include two-a-day workouts, back-to-back hard days, or an endless variety of 鈥渂rick鈥 workouts where you run after biking, bike after lifting, row after running, and so on. Yet while these sessions can generate a nice fitness boost, they are, as we mentioned, stressful on both the body and mind, which is useful only to a point. Both Kropelnicki and Dixon agree that preloaded training sessions should be used only by athletes who have already built up a solid fitness base, and these workouts should always be followed with adequate rest and recovery. In other words, be sure you can execute a long run on its own before trying to do one after biking or lifting weights. And be sure to follow preloaded training with an easy day or two.听
Another creative and less risky way to preload without causing much additional fatigue is by doing resistance exercises听with the muscles you are about to train听prior to the main workout. Kropelnicki uses this technique with distance runners to build durability, which comes in handy during the home stretch of a marathon. The听Applied Physiology paper also found that eccentric muscle contractions prior to exercise 鈥渋nduce positive adaptations鈥澨齛nd help prevent post-workout muscle pain, commonly known as delayed-onset muscle soreness (DOMS).听Eccentric sets need not be heroic to reap benefits:听For example, three听sets of 12 eccentric calf raises (performed听on a step with the heel finishing below the toes) does the trick.
Heat Training

What It Is:听According to the 听at the University of Connecticut,听heat acclimation is a 鈥渃omplex series of changes or adaptations that occur in response to heat stress.鈥 These changes enhance performance and safety in hot conditions and include a decrease in heart rate, body and skin temperature, and perceived exertions听and an increase in sweat onset, sweat rate, and blood plasma volume.听
According to coaches and scientists, heat acclimation is especially beneficial for those competing in unfamiliar听hot conditions. Without acclimatizing prior to a hot-weather race, performance will suffer, and the chance of experiencing serious health problems, like heat stroke, increase significantly.
Purplepatch鈥檚 Dixon occasionally uses this strategy for altitude racing and before key competitions since the physiological changes brought about by heat training can improve performance at altitude as well as in normal conditions. (Heat training increases blood plasma volume, lessening the effects of elevation, and the combination of adaptations can boost general fitness.) That said, Dixon emphasizes that 鈥渉eat training is extremely stressful, with risks that can outweigh rewards,鈥 and thus he doesn鈥檛 advise rushing into it unless you have a hot-weather event coming up.
How to Do It:听听suggests a protocol of seven to听14 days of 90-minute workouts in 100-degree-plus conditions. 听In practice, however, Dixon observes an effect after 30-minute low-intensity workouts in extreme heat/humidity without hydration during (but with rehydration after). Another strategy Dixon uses to reap the benefits of heat training is a sauna protocol, whereby the听athlete trains in normal conditions, quickly refuels, and then spends 15 to听30 minutes in a sauna without drinking鈥攚hich Dixon notes is not easy to do. In both strategies, Dixon sees benefits after seven to ten听days. He makes sure听the heat training regimen ends two to three days before departure to the hot-weather event.听