Stamina Decreasing for Some Exercises But Increasing for Others

Question

I've just started working out at a gym for pretty much the first time ever. I've always been really skinny - as in low body fat - but used to have decent muscle mass due to working a very physically intensive job from late high school through early college. I've now been out of that work and in a much less physical job for almost a year and lost a ton of upper body mass which is why I've now started going to the gym, which I've been doing 2-3 times a week for the past 3 weeks or so. I've been doing upper body exercises, mostly focusing on arms. I've been following a workout routine I found online, which says to do this routine 2-3 times per week. It also includes a few other exercises for the back, shoulders, etc. though for now I've been focusing more on the arm exercises and plan to start including the rest when I get better at these. My current routine consists of chin-ups, incline bench press, hammer curl, dips, and rows.

My first day at the gym was setting my benchmark/finding my limits. I found that I could successfully do:

• 6 chin-ups in one set, 4 the next, and then 3 in the next set.
• 10 reps of incline bench press at 65 lb (including bar) for 3 sets.
• 12 reps of hammer curls at 20 lbs, 2 sets, and has to decrease to 15 lbs for the last set.
• 3 dips per set, but could only do 2 sets.
• 9 reps of rows at 30 lb, 3 sets.

Using this info and the routine's recommendations, I set myself the following goals:

• Chin-ups: 3 sets of 4 reps
• Incline bench press: 3 sets of 8 reps @ 65 lb
• Hammer curl: 3 sets of 10 reps @ 20 lb
• Dips: 3 sets of 3 reps
• Rows: 3 sets of 8 reps @ 20 lb

In my next day at the gym, which was four days later, I found it difficult to meet these goals. I could barely do the 4 chin-ups even in my first set, when I could easily do 6 a few days earlier. I also struggled to do the bench press and hammer curls, though there wasn't much difference in my ability to do dips and rows. I then adjusted my routine to the following:

• Chin-ups: 3 sets of 3 reps
• Incline bench press: 3 sets of 6 reps @ 65 lb
• Hammer curl: 3 sets of 8 reps @ 20 lb
• Dips: 3 sets of 3 reps
• Rows: 3 sets of 8 reps @ 20 lb

By the way, this is the order in which I'm doing the exercises.

Since then I've been going back every second to third day, and have seen improvement in some of my exercises (specifically the ones that mostly use triceps), though the bicep/elbow flexor exercises have gotten worse. I can now do the originally planned 8 reps of bench press without too much difficulty, and the 3 sets of 3 reps of dips pretty easily, but have been struggling more and more with the chin-ups and hammer curls. I had to decrease my number of reps of chin-ups from 3 to 2, and today could barely even do all 3 reps of 2 chin-ups, when I could do 6 before. I also had to stop at 6 reps of hammer curls on my second and third sets today and last time, which was 2 days ago, when I could do 12 reps on my first day. I'm not using these muscles very much outside of the gym, and always take 1-2 rest days in between sessions. Chin-ups are also the first exercise I do of the day after a minute or two of cardio (usually treadmill), so it's not like these muscles are tired out by the time I reach this part of the routine. Why is it that I would be losing stamina for these muscles while gaining stamina for other muscles? I have usually been eating my recommended amounts of protein and always taking the recommended rest days.

Answer 1

There's a simple cause for your problem: you can't do enough chin-ups to have a steady target number of chin-ups to do in each set.

This is good news, because it means it's simple to fix. Stop aiming for a specific number of reps per set. It's too dependent on moment-to-moment fluctuations in your energy. Instead, pick a total number of reps for the workout, and get there using as many sets as necessary. That might end up being a bunch of sets of 1 or 2 reps -- that's fine.

Also consider negatives and static holds to develop positional strength after you exhaust your ability to do normal reps.

For the weighted exercises, find a progression in which you start a little lighter and make slow, consistent improvement.

Answer 2

According to the fitness-fatigue model: Observed strength (Performance) = Strength (Fitness) - Fatigue

As a result of your chin-up training your strength has increased, but you have accumulated even more fatigue and as a result your performance is dropping.

From the "The Art of Lifting":

You can do 6 reps of chin-ups, which means that when you do a chin-up you are working at the high intensity of 85 % of 1 Rep Max. This training produces a high strength (neurological muscle fiber recruitment) stimuli but the fatigue contribution is also high.

Further the last rep before failure increases the fatigue significantly and especially at high intensities (1). Instead leave 1 or 2 reps in reserve for each set. With this in mind your adjusted routine of doing 3 reps per set seems sensible. However the first day you probably acummulated a lot of fatigue going to failure on every set. I would think that with your new less fatiguing approach your fatigue will subside and your performance will increase in the coming weeks. If not try a deload week where you 1/2 the volume of all exercises.

Consider the many factors that determine strength (5): Green box around means that the factor can be trained. Doing sets of 3 of chin-ups does a good job at training the skill of doing chin-ups (technique) and neurological muscle fiber recruitment (motor skill). However as can be seen from the Fatigue and Intensity figure above it does a less than optimal job at increasing muscle size (hypertrophy) which is another factor of strength.
I think it could be beneficial to also train your lats, rectus abdominis (4), biceps and traps by doing bodybuilding style work (3). By that I mean slow controlled sets of 12 reps with max stretch. I think these sets could be done as a warm-up to your chin-ups.

Another thing you could try is to do neutral grip pull-ups instead of chin-ups. These should be a bit easier than chin-ups. That should make it easier to accumulate volume and move you more into hypertrophy zone.

Further I think chin-ups benefits from a high frequency of training. I would think every 2nd day would be ideal. For benchpress (chest) on the other hand I think every 3rd day would be ideal. This is because the back muscles have a higher percentage of slow twitch muscle fibers than the chest (2).

(1) Should You Train To Failure?

(2) Optimal Frequency Training For Hypertrophy

(3) Do More Pullups Now

(4) Muscle Activation during the Pull-up

(5) Size Vs. Strength: How Important Is Muscle Growth For Strength Gains?