11.3 Safety Guidelines, Breathing, and Teaching Biomechanics
Key Takeaways
- Default breathing for general-fitness resistance work is inhale on the eccentric or setup and exhale through the concentric sticking-point effort
- A brief Valsalva may aid experienced, near-maximal lifts with a spotter; it is contraindicated for hypertension, pregnancy, and most novices
- Sagittal-plane motions are flexion and extension; frontal-plane motions are abduction and adduction; transverse-plane motions are rotations
- Most limb actions are third-class levers; sticking points often occur where the resistance moment arm is longest
- Neutral spine is the default under load; spinal flexion is only for exercises whose intent is controlled spinal motion, not for a ‘round-back deadlift’ substitute
11.3 Safety Guidelines, Breathing, and Teaching Biomechanics
Quick Answer: DCO 3.A.3 is to teach and demonstrate general safety guidelines for movement, with the outline’s own examples — breathing and proper biomechanics. For most clients, exhale during the concentric / sticking-point effort and inhale during the eccentric or the setup. Save a true Valsalva (closed-glottis strain) for experienced, near-max attempts with a plan, and do not use it with hypertension, pregnancy, or a dizzy novice. Teach planes, levers, moment arms, and muscle actions so the spine stays neutral under load unless the exercise’s intent is a controlled spinal motion.
Breathing You Will Cue on the Floor and on the Exam
A repeatable default for general-fitness sets:
- Inhale during the easier or lengthening phase (eccentric) or during the brief setup/brace before the hard effort.
- Exhale through the hard effort — the concentric action and especially the sticking point.
- Keep a brace: the midsection stays firm as if you are about to be tapped in the stomach. Bracing is not the same as a 10-second breath-hold on every warm-up rep.
Worked example — bench press: Inhale as the bar lowers (eccentric). Exhale as the bar is pressed through the sticking region off the chest (concentric). Worked example — squat: Inhale and brace at the top or on the way down; exhale as you stand through the hardest portion of the rise.
Do not reverse this for a typical press or squat item (inhaling on the concentric and exhaling only on the way down). Do not cue a continuous breath-hold for an entire 12-rep machine set in a hypertensive novice.
Valsalva: When It Helps, When It Is a Hard No
The Valsalva maneuver is a forced expiratory effort against a closed glottis. Intra-abdominal pressure rises, the trunk becomes a more rigid cylinder, and an experienced lifter may complete a near-maximal squat, deadlift, or press more stably. Venous return drops briefly and arterial pressure spikes. Some clients get dizzy or see spots; that is a stop sign, not a badge of effort.
| Client / situation | Valsalva? | What to cue instead |
|---|---|---|
| Experienced, normotensive lifter; heavy single or double; competent spotter; no dizziness history | May use a brief closed-glottis brace through the sticking effort, then breathe | Still use collars, a known bail plan, and a spotter |
| Novice learning a goblet squat | No | Rhythmic inhale down / exhale up |
| Diagnosed hypertension or uncontrolled high blood pressure | No | Rhythmic breathing; medical clearance as required; machine or lighter loads |
| Pregnancy | No | Rhythmic breathing, no breath-holding strain; follow prenatal modifications |
| Known cardiovascular disease, aneurysm history, or client who gets lightheaded when straining | No | Stop the strain pattern; refer if symptoms appear |
| High-rep metabolic work | No | Match breath to cadence; never stack Valsalva on fatigue |
Exam trap: Valsalva is not “always malpractice” and not “required for every squat.” The NSCA-CPT answer depends on who is lifting and how heavy. Default the general client to rhythmic breathing. Do not invent a medical clearance you do not have.
Planes, Axes, and What You Are Actually Teaching
Describe motion from anatomical position. Each plane has a perpendicular axis:
| Plane | Axis | Joint actions to name | Typical exercises |
|---|---|---|---|
| Sagittal (left/right halves) | Mediolateral | Flexion and extension | Squat, lunge (forward), biceps curl, RDL, most machine leg presses |
| Frontal (front/back halves) | Anteroposterior | Abduction, adduction, lateral flexion | Side lunge, jumping jack, side-lying hip abduction, overhead dumbbell lateral raise |
| Transverse (upper/lower halves) | Longitudinal / vertical | Rotation, horizontal abduction/adduction | Cable woodchop, Russian twist, pec-deck, seated hip internal/external rotation |
A walking lunge with the torso facing forward is primarily sagittal (hip and knee flexion/extension). A lateral lunge is primarily frontal. A rotational chop is primarily transverse. Multiplanar work exists (a lunge with a chop), but the exam still wants the primary plane of the joint action in the stem.
When you teach “stay in the groove,” you are often teaching the client not to leak into a plane the exercise did not intend — for example, a sagittal squat that turns into a frontal-plane knee cave.
Levers, Moment Arms, and Sticking Points
A lever has a fulcrum (joint), an effort (muscle force), and a load (body segment plus external resistance).
| Class | Arrangement | Mechanical picture | NSCA-style example |
|---|---|---|---|
| First class | Fulcrum between effort and load | Can favor force or ROM depending on the arms | Nodding at the atlanto-occipital joint; triceps extending the elbow against a load in the hand |
| Second class | Load between fulcrum and effort | Mechanical advantage (effort arm longer) | Calf raise: ball of the foot is the fulcrum, body weight is the load, gastrocnemius/soleus pull on the calcaneus |
| Third class | Effort between fulcrum and load | Mechanical disadvantage, greater speed and ROM | Biceps curl; most throwing and kicking segments |
Most human limbs are third-class levers. That is why a 20 lb dumbbell feels heavy at the hand: the biceps insertion sits close to the elbow while the load sits far away.
Torque (the turning effect) = force × moment arm. The moment arm is the perpendicular distance from the joint axis to the line of force (muscle) or to the line of resistance (gravity or cable).
Worked numbers — biceps curl: A 20 lb (about 89 N) dumbbell held with the forearm horizontal has a long resistance moment arm roughly equal to forearm length. If that perpendicular distance is 0.30 m, resistance torque is about 89 N × 0.30 m ≈ 27 N·m. At full elbow extension, the load hangs nearly in line with the elbow and the resistance moment arm shrinks toward zero — the start feels easier even though the weight did not change. At full flexion the dumbbell is again closer to vertical over the elbow, and the moment arm shortens. The hardest point is typically near 90° of elbow flexion, when the forearm is horizontal. That region is a classic sticking point: the external moment arm is longest relative to what the muscle can produce.
Sticking points in other lifts follow the same idea plus muscle length-tension:
- Squat: often around the hole or just above, where hip and knee moments are large.
- Bench press: often a few inches off the chest.
- Deadlift: often off the floor or around the knees, depending on anthropometry and setup.
Coaching use: do not “bounce” through a stick; own it with a legal brace and a legal breath. Board presses, pin presses, and pauses are programming tools (later chapters) that change the moment-arm problem on purpose.
Concentric, Eccentric, and Isometric
| Action | Muscle length | Resistance relationship | Teaching / safety note |
|---|---|---|---|
| Concentric | Shortens | Muscle torque > load torque | Standing up, pressing, pulling the bar in; usual exhale |
| Eccentric | Lengthens under tension | Load torque > muscle torque (controlled) | Lowering the squat or the bar; usual inhale; highest force capacity; more delayed soreness if novel |
| Isometric | No net length change | Torques match | Pause at the bottom, plank, lockout hold; still needs breathing unless a brief Valsalva is indicated |
Worked tempo: A 3-1-1 squat usually means a 3-second eccentric, 1-second isometric pause, 1-second concentric. The pause is not “rest.” It is an isometric that removes stretch-reflex bounce so the client owns the ROM you educated them about in 11.2.
Eccentric control is a safety skill: clients who dump the bar onto the chest or drop into the squat hole have lost the intended biomechanics even if the concentric looks fast.
Neutral Spine Versus Allowed Spinal Motion
Neutral spine means the client keeps their natural cervical, thoracic, and lumbar curves — not a militarily flat back and not a flexed “C” shape — while the hips and knees (or shoulders) provide the ROM. Default under external load:
| Pattern | Spine expectation | Allowed exception |
|---|---|---|
| Squat, hinge, row, overhead press, loaded carry | Neutral; hips hinge or knees flex; ribs stacked over pelvis | None for a “round-back heavy deadlift” in general fitness |
| Curl-up / crunch when that is the programmed exercise | Controlled spinal flexion is the intent | Keep load modest; this is not a cue to flex the lumbar spine on a deadlift |
| Back-extension variations | Controlled extension toward neutral or slight extension as programmed | Do not bounce into end-range hyperextension under a plate |
| Unloaded cat-camel or similar mobility | Segmental flexion/extension without a barbell | Mobility is not a max-load pattern |
If the client flexes the lumbar spine on an RDL, they have changed the exercise’s purpose (11.2) and violated the default safety guideline (11.3). Cue the hinge, regress the range, or lighten the load. Do not praise “feeling it in the low back” as technique.
Spotting Introduction (Detail in Chapter 12)
Spotting is a communication and rescue skill, not a way to cheat reps. For this chapter, remember:
- Agree on rep target, lift-off (if any), and the abort word before the set.
- The spotter’s job is to prevent the load from crushing the client, not to perform the concentric for a social-media number.
- Overhead and barbell squat patterns need skilled spotting; heavy back squats often use two spotters at the bar ends. Chapter 12 covers hand position and lift-specific technique.
- Do not try to catch a moving Olympic-lift bar in flight; teach a dump/bail that matches the lift.
- Selectorized machines may not need a traditional spot, but you still watch ROM, seat settings, and pin safety.
- Collars, clear space, dry floor, and a known path for the bar are part of general movement safety, not extras.
Worked scenario — breathing plus spot: An experienced lifter attempts a heavy bench single. They may use a brief Valsalva through the press. A spotter is set, lift-off is agreed, and the client is not pregnant and is not hypertensive. A novice on the same bench doing 12 reps to “feel the pump” gets rhythmic breathing and a watchful spotter, not a closed-glottis grind on every rep.
Traps
- Exhale concentric / sticking point; inhale eccentric — unless a brief, indicated Valsalva applies.
- Valsalva + hypertension or pregnancy = wrong answer.
- Walking lunge, torso forward = sagittal, not frontal.
- Calf raise = classic second-class example; biceps curl = third-class.
- Neutral spine under load is the default; spinal flexion is not a deadlift regression.
- Spotting details for specific lifts belong with Chapter 12; communication belongs here.
For a typical general-fitness barbell bench press, the NSCA-CPT should cue the client to:
For which client is a brief Valsalva maneuver during a near-maximal squat most appropriate?
A walking lunge performed with the torso facing forward occurs primarily in which plane?
During a standing dumbbell biceps curl, the resistance moment arm of the dumbbell is typically longest when: