These days, it’s all the rage for fitness professionals to take a stand on issues facing the industry. A controversial opinion is almost guaranteed to get more likes and shares, and for every follower you lose, you’re likely to get at least five more.
One of the easiest ways to draw people into an argument is to make a blanket statement like “Just lift heavy,” “Never do crunches,” or “Forget traditional cardio, just lift weights faster.”
In fitness—as in health, nutrition, and pretty much anything else people argue about—few things are truly black and white. Almost every issue worth discussing comes in shades of gray.
So it is with the 10 hotly debated and sometimes polarizing subjects I tackle here. By exploring some of the nuances, I hope to give you a way to discuss them with your clients, and perhaps convince you to avoid the trap of taking one side or the other. The middle is a great place to be.
1. Static vs. dynamic stretching
Static stretching inhibits strength and power production  and should be avoided at all costs. Right?
Not so fast. Static stretching feels good, and many folks really need it. Moreover, dynamic stretching following static stretching negates the aforementioned inhibition .
Verdict: Prior to a workout with a client who needs to work on flexibility, start out with static stretches, then move to more dynamic mobility exercises. You may also want to use static stretches at the end of the workout.
READ ALSO: Why You Must Not Stretch Hypermobile Clients
2. “Just squat, bro!” vs. corrective exercise
The big lifts themselves may be corrective in nature to a certain extent, but when a client displays severe valgus, butt wink, and excessive forward inclination of the torso, “Just squat, bro!” isn’t the best programming strategy.
While it’s just plain silly to roll around on the floor for an hour and call it personal training, a couple of targeted corrective exercises, as determined by some sort of screening criteria, can go a long way towards improving movement quality and staying safe in the gym .
Verdict: If a client is cleared to squat, by all means squat away. But for a client with the aforementioned issues, find safer and more appropriate alternatives.
READ ALSO: Why People MUST Squat Differently
3. Compound vs. isolation exercises
Multijoint movements—squats, hip hinges, presses, rows, lunges—should be the foundation of any good program. But that doesn’t mean compound movements are the best choice for every muscle group.
Take the hamstrings and biceps, for example. Since they don’t change length appreciably during compound lifts, isolation is actually the best way to strengthen them . Especially if these muscles are weak links in the chain, isolation is a must. Plus, it’s nice to give your clients what they want (when it won’t hurt them).
Verdict: Emphasize compound lifts, but also incorporate single-joint exercises to strengthen weak links and as “icing on the cake.”
4. Bilateral vs. unilateral lower-body training
Unilateral exercises provide the same benefits as their bilateral counterparts  with half the compressive force on the spine and an added stability requirement. Two-legged squats and deadlifts certainly aren’t dead, as some have claimed. The key is to strike an appropriate balance.
Verdict: A one-to-one ratio of unilateral to bilateral lower-body exercise should work well for most clients. Pair a bilateral knee-dominant exercise with a unilateral hip-dominant exercise in one session, and flip-flop movement patterns in the next.
5. Low vs. high reps
Anything over six reps is cardio, and we all know how cardio destroys gains . Can I hear an amen?
Actually, because of variations in fiber-type composition, different muscles will get the best hypertrophy response from different—and often multiple—rep ranges. Choose a variety of set and rep schemes for clients whose goal is maximal muscular development .
Verdict: Hit multiple rep ranges (low, medium, high, super-high) throughout the week, or vary them from one training cycle to the next.
READ ALSO: A Trainer’s Guide to Building Muscle
6. Full-body lifts vs. direct core work
Full-body barbell lifts do, in fact, elicit high levels of core activation .
Even so, almost every client will benefit from direct core work, either at the beginning or end of the session, if not both. Moreover, as with isolation exercises for biceps and triceps, most clients expect their program to include at least one or two “ab” exercises. Choose them carefully, and your clients can get what they want while you shore up their weak links.
Verdict: On top of the full-body lifts, select direct core exercises that address each client’s needs and goals.
READ ALSO: Five Steps to Superior Core Training
7. Spinal flexion and rotation vs. core stability
On one side, you’ll find experts (along with “experts”) who argue that the purpose of the core is to prevent motion, not create it . The most extreme will compare the human spine to a credit card, and repeatedly bending and twisting it will, over time, cause it to snap.
The research is frustratingly equivocal. Anecdotally, we hear about freaks who do hundreds or even thousands of crunches per day and someone remain free of back pain. But we would never bet on careers on the possibility that one of our clients is among them.
It’s logical to assume too much flexion and rotation can be dangerous, especially for deconditioned or previously injured clients. You can’t go wrong by choosing safer options. But for clients who want them, you can get away with a few sets of crunches or carefully controlled Russian twists. Heck, they may even provide some salubrious effects along with the aesthetic value .
Verdict: Train primarily for core stability, although it’s probably harmless to occasionally hit the abs directly with some low-rep flexion or rotation exercises.
8. Traditional cardio vs. metabolic resistance training
Performing heavy, technical lifts for in a fatigued state is risky . But for clients who’re ready for it, metabolic resistance training—lifting weights faster—can be both fun and beneficial. But don’t disparage traditional cardio, especially for clients who like to do it on their own in between their workouts with you.
Verdict: Use a mix of metabolic resistance training (with appropriate exercise selection) and traditional cardio.
9. Advanced monitoring techniques vs. wellness questionnaire
Your clients can monitor every step, breath, bite, and heartbeat. But just because they can measure esoteric things like heart-rate variability, does that mean they should?
For starters, the high-tech bio-monitoring tools are effective for measuring recovery . But they also encourage obsessive behavior. Like the scale, they sometimes produce more anxiety than they’re worth.
Most clients will do fine with a simple daily wellness questionnaire . Questions like “How well did I sleep?”, “How sore am I?”, and “How excited am I to train today?” will help them get attuned to their body and its readiness to train.
For the middle ground, a basic heart-rate monitor provides useful information for as little as $50.
Verdict: A daily wellness questionnaire, along with a cheap heart-rate monitor, will give most clients all the data they really need.
10. Interval training vs. steady-state cardio
We’ll concede there’s little benefit to plodding along on a treadmill while watching The Great British Baking Show, or pedaling a stationary bike slow enough to read a magazine .
On the other hand, you should be extremely skeptical of anyone who claims there’s no benefit to traditional, steady-pace endurance exercise. Even worse are the ones who say things like “train slow, be slow,” or claim that cardio makes you fat. We know it provides cardiovascular benefits you can’t get from intervals . It’s also good for recovery . Heck, some people even enjoy it!
None of that is to say interval training doesn’t offer some great perks, like shorter workout times  and endless variety in terms of work-to-rest ratios.
Verdict: Get the best of both worlds by alternating interval training with traditional cardio.
READ ALSO: The Myth of Fat-Burning Workouts
Never forego an entire training methodology simply because one expert, in an effort to get attention, insists on its uselessness. Avoid such polarizing debates on fitness topics. When you keep an open mind, you’ll find that the middle of the road is the most defensible position on most issues. By exposing your clients to a full range of training stimuli, you improve their health and fitness in multiple ways, and give them reasons to look forward to your training sessions.
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