It seems like just the other day you were doing your usual kick-ass chest routine and got an amazing pump. Your pectorals felt like they were jumping out of your shirt. You felt great and looked huge. The muscles enjoyed a deep soreness, then a nice fullness in the days that followed. Your energy was awesome, your strength was fantastic, and it seemed like the more you did, the more your body ate it up.

But then your energy disappeared, along with those great pumps. Throughout your body, all you felt was flattened out. Strength took a dive. You tried to push through it by adding sets, changing exercise sequences, trying one of those pre-workout drinks, doing forced repetitions, even upping your calories. Yet it was all to no avail. It never dawned on you to take some time off and give that area a rest, even after losing size. That concept was just too counterintuitive for you to embrace.

It didn’t make any sense that you should actually do less for a body part that’s fading. So, instead—though you hate to admit it to yourself—you panicked and went in the opposite direction. You ended up adding an extra chest workout, basically hitting chest a little more often in an effort to jolt the area back to life.

You even tried to force up the usual weight from before you started feeling the bottom. And that was the biggest mistake, because then it happened: You injured yourself. Not terribly, but enough to send a powerful message deep down into your psyche that you truly had to back off.

So what the hell happened?

The answer is that you were overtrained. You never really thought it could happen to you, but it did.

The lesson: Never, ever underestimate how truly diffcult it is to know when you’re training too frequently, performing too many sets for a body part, or, most importantly, are flat-out overtrained. While less-experienced lifters are the most vulnerable, even the most seasoned bodybuilders fall into this trap because it’s tough to let go of the twisted belief that more is better. So, before you get too caught up in adding more sets, more reps, or more frequent workouts with fewer days of, know that if you go that route, overtraining is just around the corner. It’s an unintentional form of self-inflicted bodybuilding suicide that all too easily goes unrecognized until suddenly it’s too late.

Often times, the signs of overtraining aren’t those you’d expect. Perhaps the most esoteric and challenging symptom to associate with the phenomenon is the loss or lessening of delayed onset muscle soreness (DOMS). While DOMS is often taken as a sign of less-than-optimal conditioning by many athletes who consider it the bane of their existence, for bodybuilders it’s an absolutely critical end point, one that signifies adequate muscle taxation and, therefore, impending muscle growth through recovery. For the bodybuilder, DOMS is a goal for most every body part. Though not all your body parts will respond this way, soreness is a barometer with which you can measure whether you’ve hit a muscle hard enough.

So when DOMS doesn’t occur after a very tough workout on a body part that tends to get sore easily and regularly, it may be a sign of overtraining. When that happens, you must fight the urge to hit that body part again too soon. That’s one of the toughest things to resist in bodybuilding, because when you don’t feel the muscle blown away, you feel as though you didn’t do enough, and want to go right back at it. Most every bodybuilder has been guilty of this at one point or another. However, the key is to remind yourself that just because a body part isn’t sore, that doesn’t mean it doesn’t need the same recovery time or perhaps even more recovery time than usual.

But whether it’s diminished DOMS or one of the other signs I’ve described—or even if it’s a symptom I haven’t mentioned—the point is to be acutely aware of unwelcome changes in your body’s response to training.

The story I told in my introduction is a classic example of overtraining signified by low energy, a flat pump, and a strength drop. These early symptoms may occur in isolation or together. I’ve noticed over the years that some of the earliest symptoms—though they vary considerably from person to person—include a lack of motivation and a slight drop in appetite. According to a recent study in Japan, this may be due to the hormonal effect of appetite related substances in our bodies. These include endocrine regulators of appetite and energy balance, such as ghrelin and leptin. The study’s findings suggest that decreased concentrations of ghrelin and leptin are early signs of accumulated fatigue, signifying that the body has experienced excessive physical stress and that an overtrained state has begun.

The same study also showed significant reductions in the fasting concentrations of serum insulin-like growth factor-1 (IGF-1) and free testosterone, confirming that anabolic hormones suffer as well. This may further explain the myriad negative symptoms that signal when a crash has begun.

Of course, all this can likely be avoided if you have the maturity and self-control to follow my instructions and apply some of these suggestions. Before you start, however, there are some important points to consider regarding stimulating the muscle while stopping short of annihilation.

The first involves knowing when you’ve performed enough sets, as doing too many sets is the most common mistake leading to overtraining. So, when it comes to the number you decide upon, you must be careful not to overdo it. Although the total number of sets needed varies from one body part to the next and from one person to the next, there are some nuances that broadly apply. In particular, pay attention to fatigue, and save working to failure and forced repetitions for the end of the workout of that body part. If you’re working to failure and forcing repetitions every set, you’ll have no idea when the muscle is shot and you should stop training it. You’ll be numb at that point, and beaten beyond practical recovery. The key is to know and to feel what you’re doing at all times. If you’ve failed on the last repetition of a set and you’ve got at least a few sets behind you, it might be a good time to stop.

The next tip for avoiding overtraining is to pay close attention to your pump. Training beyond a maximum pump isn’t usually helpful for muscle growth, and can actually be counterproductive. Strive to understand your body so you know when your muscles are maximally pumped—then attempt to move on before the first sign of deflation.

Working a given body part too frequently is another sure way to overtrain. I recall learning firsthand from bodybuilding legend Steve Reeves that excessive training frequency invariably leads to overtraining. Reeves, a former Mr. Universe, was famous for starring in the early Hercules films, and was widely considered by experts in the field to have one of the most timeless and near-perfect bodybuilding physiques in history.

But what was little known about Reeves was that he was a true physical technician who spent countless hours “figuring out” his body. When he really wanted to see what a particular exercise was doing to a specific muscle, he’d refrain from training that muscle for two weeks, then do just the one motion in question. That resonated with me because, in the years that followed, I developed my own approach to avoiding overtraining by choosing a body part to miss every week or two. I’d rotate and work my way through every body part so at some point or another my entire body would get more rest.