Exercise, Movement & Nutrition
Exercise and nutrition are inseparable — each amplifies the benefits of the other. Being active changes what you need to eat. This guide covers the Australian guidelines, how exercise shifts your nutrient requirements, and how to fuel activity on a real budget.
Australian Physical Activity Guidelines summary
| Age Group | Weekly Cardio Target | Strength Training | Sedentary Behaviour |
|---|---|---|---|
| Children 5–12 | 60 min/day moderate-to-vigorous | 3×/week muscle & bone strengthening | Max 2hrs recreational screen time/day |
| Teens 13–17 | 60 min/day; some vigorous | 3×/week resistance & bone-loading | Break up sitting; limit leisure screens |
| Adults 18–64 | 150–300 min moderate OR 75–150 min vigorous/week | 2×/week muscle-strengthening | Break up long sitting regularly |
| Older Adults 65+ | 150–300 min moderate/week | 2×/week strength + balance | Move more, sit less; any activity counts |
Why strength training is non-negotiable
More muscle means better glucose regulation, better bone density, lower fall risk, and longer independent living. Sarcopenia (age-related muscle loss) begins in your 30s at approximately 1% per year if not actively counteracted. Weight training directly reverses this.
Just 2 sessions per week of resistance exercise reduces type 2 diabetes risk by 30–35%. The mechanism is separate from and additive to aerobic exercise benefits.
Weight-bearing resistance exercise is the most effective non-pharmacological strategy for reducing osteoporosis risk — more effective than calcium supplementation alone.
Push-ups, squats, lunges, planks, and bodyweight rows are free and fully effective for most people. A set of resistance bands (~$15 once) and a backpack filled with books covers progressive loading. No ongoing costs required.
How exercise changes your nutrient requirements
| Nutrient | Target for Active Adults | Why It Changes | Budget Strategy |
|---|---|---|---|
| Protein | 1.2–1.7 g/kg/day (active) vs 0.75 g/kg sedentary | Muscle repair and synthesis after resistance exercise. Upper end (1.5–1.7) for weight training; lower-mid (1.2–1.4) for endurance | Eggs + lentils + sardines covers most needs at ~$1.50/day extra |
| Carbohydrates | 4–7 g/kg/day for performance | Primary fuel for moderate-to-high intensity exercise. 1–1.5 g/kg post-exercise for glycogen recovery | Oats, banana, rice, bread — the cheapest energy sources |
| Iron | Female athletes: up to 30% higher need | Foot-strike haemolysis (red cell destruction from impact), sweat losses, and increased turnover | Weekly red meat or liver; combine with Vitamin C foods always |
| Magnesium | 10–20% above sedentary RDI | Muscle contraction, energy production, lost in sweat. Hot Australian summers increase losses significantly | Pumpkin seeds (534mg per 100g), spinach, lentils |
| Electrolytes | Increases with sweat volume | Sodium, potassium and magnesium lost in sweat. Critical in hot, humid conditions | Banana + pinch of salt + water beats sports drinks at 1/20th the cost |
| Omega-3 | 1.6g ALA/day + EPA/DHA beneficial | Anti-inflammatory; supports muscle repair, may reduce DOMS and improve recovery time | Sardines 2×/week, ground flaxseed on oats daily |
| Vitamin D | Same RDI but more consequential | Supports muscle fibre development; deficiency measurably impairs strength gains and recovery | 15–30 min sun on arms/legs most days; supplement in winter |
Protein timing — when you eat matters as much as how much
Breaking the overnight catabolic cycle — why your first meal matters most
The overnight fast — what’s happening in your body
During an 8–12 hour overnight fast, the body enters a catabolic state by necessity. The brain needs glucose continuously. With no incoming food, the body runs gluconeogenesis — manufacturing glucose from amino acids stripped from muscle tissue. This is normal and unavoidable. What matters is how long it continues after you wake up.
The cortisol awakening response peaks approximately 30–45 minutes after waking. This morning cortisol spike is catabolic by design — it mobilises energy for the day ahead by breaking down protein stores. It’s a feature, not a bug. But combined with an already-fasted state, it means you’re in maximum catabolism at 7am.
The leucine threshold — what it takes to flip the switch
Muscle protein synthesis is triggered by the mTOR pathway, and leucine is the essential amino acid that directly activates it. The threshold for switching from net breakdown to net building is approximately 3g of leucine per meal — equivalent to roughly 30–40g of complete protein.
Common breakfasts — do they hit the threshold?
| Breakfast | Protein | Leucine (approx) | Flips anabolic switch? |
|---|---|---|---|
| 2 slices toast + vegemite | ~8g | ~0.5g | No |
| Bowl of corn flakes + milk | ~9g | ~0.6g | No |
| Banana + coffee | ~1g | ~0.1g | No |
| 2 eggs on toast | ~18g | ~1.4g | Borderline |
| 3 eggs scrambled | ~21g | ~1.7g | Borderline |
| 2 eggs + 200g Greek yoghurt | ~32g | ~2.7g | Yes ✓ |
| 3 eggs + 250mL milk | ~30g | ~2.5g | Yes ✓ |
| 2 eggs + 100g cottage cheese + toast | ~33g | ~2.8g | Yes ✓ |
| Greek yoghurt (200g) + pumpkin seeds + oats | ~28g | ~2.2g | Yes ✓ |
For older adults — the stakes are higher
Due to anabolic resistance, the leucine threshold rises to approximately 3.5–4g per meal for adults over 65 — requiring 35–40g of high-quality protein to trigger the same muscle-building response. A typical low-protein breakfast in an older adult isn’t just suboptimal — it’s actively contributing to sarcopenia, one meal at a time, compounded every single morning for years.
The compounding effect
One subthreshold breakfast doesn’t cause noticeable muscle loss. But 365 of them per year, for 10 years, compounded by gradual activity decline, is one of the primary mechanisms behind why people lose significant muscle mass as they age — and why it happens gradually enough that most people don’t notice until function is already compromised.
Budget active person — weekly blueprint
Movement (free or near-free)
Nutrition adjustments (budget-aligned)
Sedentary behaviour — the hidden risk
Physical inactivity is the fourth largest risk factor for global mortality. But separate from exercise, prolonged sitting is an independent risk factor — even in people who exercise regularly. An hour of gym does not undo eight hours of sitting.
Sarcopenia — the muscle loss crisis in ageing
Sarcopenia affects an estimated 10–20% of Australians over 65, rising to 30–50% over 80. It is the leading cause of falls, fractures, disability, and loss of independence in older adults, with an annual economic cost exceeding $2.5 billion in Australia.
Exercise for special populations
📷 See your household's exact nutrient targets in the free app — enter each person’s age and sex to see their exact targets and how your meals measure up.
Open free appSources: Department of Health Australia. Physical Activity and Sedentary Behaviour Guidelines (2021) · Cruz-Jentoft AJ, et al. “Sarcopenia: revised European consensus.” Age Ageing. 2019 · ACSM Position Stand on Nutrition and Athletic Performance · Colberg SR, et al. “Physical Activity/Exercise and Diabetes.” Diabetes Care. 2016 · Bauer J, et al. “Evidence-based recommendations for optimal dietary protein intake in older people.” J Am Med Dir Assoc. 2013