It was most likely just a bad training session.
Dan John, one of the most experienced and knowledgeable strength training coaches in the world, says that you should expect 20% of your workouts to be “duds”. Off days. Days where your strength just “isn’t right”. Start a training program with this in mind and don’t let it rattle you when it happens because it’s normal. Go home, eat, rest, and sleep well, and come back the next time with a determined attitude.
“It definitely wasn’t just that.”
First, be aware of the tendency for our brains to panic and immediately seek the worst case scenario. (Ah, I’m losing muscle!)
Reduction in body measurements in all areas doesn’t necessarily mean muscle loss, it can just mean fat loss, as fat does get stored on, and get burned off of all areas of the body. However, if this is combined with strength losses then it may be a concern.
There are a number of things that it could be. I’ll share some things that go through my mind when assessing things for clients, this would be a general order:
- Are you stressed?
- Are you sleeping fine?
- Was it just a bad workout?
- Are you coming down with something, fever or a cold?
- Is it hayfever (seasonal pollen allergy in some countries) that is kicking your ass right now?
If no to all of the others, then we move onto the next stage:
- Is the level of strength decrease within the accepted and expected range when cutting (up to ~10% depending on circumstance) due to the mechanical inefficiency of being leaner? (More on this in the box below.)
- Do you need a diet break? (frequency guidelines) – If yes, take one and see how your strength is after taking a diet break.
- Is your protein intake sufficient? Consider double-checking your counting. (protein intake guidelines)
- Is your weight dropping, on average, more than the recommended amount for your body fat percentage at the moment? (maximal fat loss rate guidelines) – If yes, increase calories.
- In the unlikely event that none of the above is applicable and your lifts continue to decrease without any other explanation, increase the energy intake until that ceases. Track. Reconsider options.
I’ve written this off the top of my head but it’s a fairly solid checklist that’ll cover most situations.
The Mechanical Disadvantage of Being Leaner
Recall your high school physics class, work = force x distance.
As fat is lost the relative distance the bar has to travel gets greater. This is most easy to picture when you consider the bench press. If you are leaner, the same resistance for the same number of reps will be a greater amount of total work done. Thus a small decrease in the weight on the bar is not necessarily indicative of a drop in strength, rather, if strength were to stay the same, all things being equal, your bench would drop on a cut.