Which Fitness Group Are You?

Walk through the gym on any given morning and you can see four different patterns. Most members fall cleanly into one of them. Each has a different prescription. Read the four groups below, decide honestly which one you’re in, and read that prescription carefully. The body responds to the right input at any age — but only when you give it the right input.

Read Your InBody First

Before you decide which group you belong to, pull out your most recent InBody 570 printout. If you haven’t had a scan in the last ninety days, get one before you finish reading this article — guessing your group from the mirror is the most common mistake members make, and the mirror is the least reliable instrument we have. Five readings on the printout tell you almost everything.

The five readings that matter

1. Skeletal Muscle Mass (SMM). Top of the page, in pounds, displayed as a horizontal bar with a tick mark for the average value for someone your height. Is your bar to the left of the tick (below average) or to the right (above average)? This single line is the most important number on the page.
2. Percent Body Fat (PBF). Just below SMM, also with a bar and a tick mark. Healthy ranges for adults over 50: roughly 15–22% for men, 22–26% for women. Above 25% (men) or 30% (women) is the red zone, regardless of weight.
3. Visceral Fat Level (VFL). The deep abdominal fat wrapped around your organs — by far the most dangerous fat on your body. VFL of 1–9 is healthy. 10–14 is borderline. 15 and above is high cardiovascular and metabolic risk, even if you look fine in clothes.
4. ECW/TBW ratio (Extracellular Water over Total Body Water). Found in the body water section. Under 0.380 is healthy cellular function. 0.380–0.390 is creeping inflammation or muscle-quality decline. Above 0.390 signals systemic inflammation, poor recovery, or sarcopenia in progress. This is one of the most underappreciated numbers on the whole sheet.
5. Segmental Lean Analysis. The five horizontal bars in the middle of the printout, one for each body segment: right arm, left arm, trunk, right leg, left leg. Each is shown as a percentage of what’s expected for someone your size — 100% is average, anything above is above-average lean mass for that segment, anything below is a deficit. Look for two things: are the bars above or below 100%, and are right and left roughly equal? Big left-right asymmetry signals an old injury or a one-sided training pattern that needs correcting. Legs well below 100% is the single most important warning sign for falls and sarcopenia after 50.

The shape of your Muscle-Fat Analysis graph

The three bars at the top of the printout — Weight, Skeletal Muscle Mass, and Body Fat Mass — form a visual pattern relative to their tick marks. The shape itself is diagnostic at a glance:

• D-shape — Weight near average, SMM bar long and to the right, Body Fat bar short and to the left. The goal. Group 4.
• Athletic shape — All three bars long and to the right. Muscular, but watch the visceral fat and waist measurements for the Group 2 pattern.
• I-shape — All three bars roughly aligned and often short. Group 1 if body fat is low, Group 3 if body fat is high.
• C-shape — Weight near average, SMM bar short and to the left, Body Fat bar long and to the right. The sarcopenic pattern. Group 3, and the trajectory we most need to interrupt.

Quick diagnostic — which group does your scan say you’re in?

Group 1 (thin, cardio-fit, under-muscled). SMM bar to the left of the tick. Body Fat % may look fine or even low — that’s the trap. Visceral Fat Level usually under 10. Segmental Lean Analysis shows most or all segments under 100%, often noticeably so in the legs. Weight looks fine on paper, but the muscle deficit is the story. The shape is often a short, balanced “I.”

Group 2 (strong, under-trained aerobically). SMM bar to the right of the tick — sometimes well to the right. Segmental Lean Analysis shows segments at 100% or above across the board. But Visceral Fat Level is 10 or higher, the Waist-Hip Ratio is creeping up, and the ECW/TBW ratio is drifting toward 0.385 or above. The muscle numbers look great. The visceral and inflammation numbers tell the real story.

Group 3 (doing little of either). SMM bar to the left of the tick. Body Fat % above 25% for men or 33% for women. Visceral Fat Level 13 or higher. ECW/TBW often 0.390 or above. Segmental Lean Analysis shows most segments — and especially the legs — well under 100%. The classic C-shape.

Group 4 (doing both well). SMM bar clearly right of the tick. Body Fat % in the healthy range. Visceral Fat Level under 10. ECW/TBW under 0.380. Segmental Lean Analysis shows every segment at or above 100%, with the right and left sides roughly symmetrical. The D-shape!

Take a second look at your scan. Find your group. Then read the prescription below and stay with it. If your printout straddles two groups, choose the group that names the pillar you’re weakest on — that’s where the next ninety days of work belong.

Group 1: Thin, cardio-fit, under-muscled

You’re a familiar face in spin or aerobics. You walk daily. Your cardiovascular fitness is excellent. But your InBody shows skeletal muscle mass below the population norm for your age. You probably look “healthy.” You’re quietly progressing toward sarcopenia anyway, because you’ve never built the muscle reserve. When you fall at 75, your VO2 max won’t catch you.

This is the most common pattern among our long-time aerobic members, and it is the easiest to fix once we name it. You already have the discipline. You just need to redirect a portion of it.

Your priority: build muscle.

Resistance training — how to do it

Frequency. Two to three sessions a week, with at least 48 hours between sessions on the same muscle group. Twice a week is enough to make real progress; three times a week is the sweet spot for most members over 50.

Reps and sets. Work in the 6 to 12 rep range. This is the hypertrophy zone — the rep range that signals the muscle to grow. Three working sets per exercise is a sound target. The last two or three reps of each set should feel hard. If rep twelve feels easy, the weight is too light.

Focus on large muscle groups. Big muscles drive the systemic hormonal and metabolic response. Train the small muscles only after the big ones are handled. The non-negotiables:

• Thighs (quadriceps and hamstrings) — leg press, hack squat, Romanian deadlift, leg curl, leg extension.
• Glutes — hip thrust, glute bridge, cable kickback, walking lunge, step-up.
• Back and lats — lat pulldown, seated row, cable row, assisted pull-up.
• Chest — chest press machine, dumbbell bench press, incline press.
• Shoulders — seated overhead press, lateral raise.
• Core — planks, cable rotations, weighted carries. Five to ten minutes at the end.

If you’re unsure how to set up any of these movements, ask any Shape-Up coach on the floor. We will walk you through the equipment, set the seat, and watch your first few reps. That’s what we’re here for.

Progressive overload. Each week, try to add a little — one more rep, a little more weight, or a slightly cleaner form. The muscle will not grow if the demand never grows.

Protein — how to eat it

You almost certainly aren’t eating enough. Aerobic-oriented members under-eat protein as a near-universal rule. Aim for roughly .8 to 1 gram of protein per pound of your ideal body weight per day, spread across three meals at 30 to 40 grams each. The body can’t bank protein. A 60-gram dinner doesn’t make up for an 8-gram breakfast.

Protein at each meal

Breakfast (the meal most members under-eat). Three whole eggs plus Greek yogurt; cottage cheese with berries; a whey or whey-and-casein shake blended with milk; smoked salmon on whole grain with eggs; leftover chicken from last night’s dinner. Target: 30 to 40 grams.

Lunch. Grilled chicken breast over a real salad with olive oil; canned wild salmon or tuna with avocado; turkey breast with hummus; lean ground beef with vegetables; lentils plus a side of cheese or yogurt for a complete amino acid profile. Target: 30 to 40 grams.

Dinner — and eat it early. Salmon, sirloin, chicken thighs, white fish, or a real serving of beans with cheese. Try to finish dinner at least three hours before bed. The earlier the better — your sleep, your digestion, and your overnight fat oxidation all improve when the kitchen closes by seven.

A practical note on aerobic volume. You may need to slightly reduce aerobic volume to support recovery from your new strength work — especially in the first eight weeks. One spin class swapped for one resistance session is a great trade for someone in this group.

Group 2: Strong but under-trained aerobically

You lift. You have respectable muscle mass. You look good. But you don’t do meaningful cardiovascular work, and the metabolic signs are creeping in — elevated fasting glucose, borderline blood pressure, a widening waist. You likely have more intramuscular fat than you should, because muscle without aerobic demand stops processing fat efficiently. Your long-term cardiovascular risk is higher than your appearance suggests.

The mirror is lying to you. The blood work is telling the truth.

Your priority: build cardiovascular capacity.

Use METs as your measuring stick

A MET — Metabolic Equivalent of Task — is a measure of work rate. One MET equals what your body burns sitting still. Eight METs means you are working at eight times your resting rate. That is the threshold where cardiovascular adaptations really start to accumulate in the 50-plus body.

Your target: an average of 8 METs or more sustained for 5 to 10 minutes. You can do multiple times per session, two to three sessions per week. Build to it gradually. If you’re starting at an average of 4 METs, that’s fine — move up half a MET every week or two.

Measuring METs on our equipment

Every piece of Matrix cardio equipment in the gym displays your MET score in real time and your average MET for the session. Use the display. Train to a number, not a feeling.

• Treadmill — speed and incline both push the MET score up. A 3.5 mph walk at 6% incline often hits 8 METs for most members.
• Upright bike — easier to push harder without joint stress. Watch the resistance level and RPM together as they both increase the MET level.
• Recumbent bike — gentler on the back; you can still drive METs up by adding resistance and cadence.
• ClimbMill — the highest-MET machine in the building per minute of effort. A genuine 8 MET pace here is honest work.
• Elliptical — use the arms and the resistance together; passive arm-swinging doesn’t move the MET score.

The number on the console is the truth. If you’ve been on the bike for forty minutes at 3 METs, you got a pleasant ride. You did not get a cardiovascular training stimulus.

MET equivalents outside the gym

If you train outdoors, here is roughly what 8 METs feels like:

• Walking — very brisk pace, 4.0 to 4.5 mph. Most members can’t sustain this on flat ground; add hills.
• Jogging — around 5 mph, a 12-minute mile. This is the most efficient way to reach 8 METs without equipment.
• Running — 5.5 to 6 mph clears 9 to 10 METs comfortably.
• Cycling — 12 to 14 mph on flat ground, or moderate effort on rolling hills.
• Swimming — steady freestyle laps; moderate-to-vigorous effort puts most swimmers in the 7 to 10 MET range.

Shape-Up classes and where they land

Our group classes are an efficient way to hit MET targets without thinking about the dial. Approximate average MET ranges:

• Indoor Cycling — 7 to 10 METs. One of our highest-intensity classes.
• Body Combat — 7 to 10 METs. Sustained punching, kicking, and footwork.
• Dirty 30 — 7 to 10 METs. Short, intense, and well-designed for our demographic.
• Cardio Dance — 6 to 8 METs.
• Zumba — 6 to 8 METs.
• Body Sculpt — 5 to 7 METs. Strength-oriented; supplement with one of the higher-MET sessions above.
• Abs and Booty — 5 to 7 METs. Excellent supplement; not a stand-alone cardio prescription.

Two classes a week from the 7-to-10 MET tier, alongside your existing strength work, will move your blood work numbers and you body composition within ninety days. We have seen it again and again. The 6 Week Challenge gets you half way there.

Group 3: Doing little of either

Higher total body fat. Higher visceral fat. Advancing IMAT. Low skeletal muscle mass. Declining bone density. This is the trajectory most Americans over 50 are on by default. The standard medical system tells you that some of this is “inevitable” or “natural.”

It isn’t. Every single one of these problems is REVERSIBLE — not “improvable,” not “slowable,” reversible. Members in their late 60s and 70s have come into Shape-Up in this exact state and rebuilt themselves over twelve to eighteen months. The body is more responsive than people are told.

Your priority: begin. Gently, consistently, with both pillars.

Start with both strength and aerobic work the same week. Don’t spend three months “doing only cardio” and then add weights later — the muscle loss will outpace the cardio gain. Both, from day one, but small.

Week-one prescription

• Two short resistance sessions, 25 to 35 minutes each. Machines, not free weights, until your coach moves you up. One exercise per major muscle group, two sets of 10.
• Two cardio sessions, 20 minutes each, on the recumbent bike or treadmill at whatever MET score you can hold a conversation through. Don’t chase a number yet.
• One real rest day in between each session.
• Protein at every meal — 25 to 30 grams. This alone will change how you feel within ten days.
• Sleep seven hours. Non-negotiable. Recovery is where the body actually rebuilds.

What to expect

The first six weeks are the hardest. You will be sore. You will feel uncoordinated. You will doubt whether it is working. It is. By week three the soreness drops sharply. By week six the sessions feel like part of your life rather than an interruption to it.

By month three you’ll feel different. Energy is up. Sleep is better. Clothes fit differently. The InBody numbers begin to move visibly — first water shifts, then visible muscle, then fat. By month six the change is undeniable, including to your doctor. By month twelve to eighteen, the trajectory has reversed.

Six weeks builds the habit. Three to six months builds the body. Keep that sentence in your head when the first weeks feel slow.

The most important thing you can do is show up four times a week, even briefly, even tired. Consistency over intensity. Always.

Group 4: Doing both well

You train resistance two to three times a week. You get aerobic work in. You eat enough protein. You sleep. Your InBody numbers look the way numbers should. This is the goal for everyone in this room, and it is genuinely achievable from any starting point.

Your priority: maintain — and adjust as you age.

The mistake at this stage is assuming you can run the same program forever. The body at 70 doesn’t recover like the body at 35. Small, deliberate adjustments every few years preserve everything you’ve built.

Adjust gradually

• Protein, slightly higher. Anabolic resistance is real — the older muscle needs more of the signal to respond. Push toward the upper end of your range, roughly 1.0 to 1.2 grams per pound of ideal body weight per day.
• Recovery, slightly longer. If you used to lift three days in a row and feel fine, you may now need a rest day after every heavy session. Listen to it. Recovery isn’t weakness; it’s where the adaptation happens.
• Volume, slightly adjusted. Fewer junk sets, more focused work. Two excellent sets beat five tired ones. Quality over quantity becomes the rule.
• Cardio, keep the intensity. Don’t drift down only to long, easy walks. Easy walks are for recovery days. Keep at least one true 8-MET session a week. Maintained intensity is what preserves VO2 max into your 80s.
• Mobility and balance. Add five to ten minutes per session. Single-leg work, ankle mobility, thoracic rotation. This is what keeps you off the floor at 80.
• Re-scan your InBody quarterly. Catch drift early. A 1% drop in skeletal muscle mass over a quarter is easy to reverse in the next quarter — and easy to ignore until it isn’t.

The twenty-year view

Members in this group often ask what to aim for next. The answer is the same answer for the next twenty years: the same protocol, refined, with one or two intelligent adjustments per year, executed without drama. The people who stay strong, mobile, and metabolically healthy into their late 80s and 90s are not doing anything dramatic. They are doing the correct work — week after week, year after year. That is the entire game.

Choose your group. Choose your priority.

The prescription applies to all four groups — protein at every meal, resistance training two to three times a week, sustained cardiovascular work, sleep, recovery. The difference between the groups is which pillar needs the most attention right now. Get that pillar right first, and the rest follows.

If you’re not sure which group you’re in, ask us. Better yet, get a fresh InBody scan this week. We’ll read it with you and tell you honestly.

Next week: anabolic resistance — the single most important fact about aging muscle, and the reason protein timing matters more after 50 than it ever did before.

— Robert Burns
Owner and Head Coach, Shape-Up Health Club