Balancing Exercise and Nutrition While Using Weight-Loss Injections

While using a weight-loss injection, exercise is one of the strongest helpers in preserving muscle mass during weight loss and in keeping the weight off afterwards. Combined with resistance exercise on at least two days a week and moderate-intensity activity such as regular walking, enough protein at every meal, a light snack before training and enough fluids through the day, it helps build a healthy balance. Get your doctor's approval before starting an exercise plan.

Because medicines such as semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) reduce appetite markedly, it can become hard to get the energy and protein needed for an active day. In this article I explain the place of exercise in this process and how to build an eating routine that fits with training. These medicines are used only with a doctor's prescription and follow-up.

Why Does Exercise Matter While Using a Weight-Loss Injection?

Weight loss with these medicines is usually fast, and part of the weight lost can come from muscle tissue. As muscle mass falls, daily energy expenditure drops and strength and balance weaken; this makes both daily life and keeping the weight off after the medicine harder.

Regular exercise, especially resistance exercise, gives the muscle the signal “I am being used, I should be kept”. Exercise also supports cardiovascular health, blood sugar control, sleep quality and mood. The NIDDK and the NHS also stress that these medicines should be used together with balanced eating and increased physical activity.

I covered the nutrition side of muscle loss in detail in the article on whether it is possible to lose weight without losing muscle.

What Should a Weekly Exercise Plan Look Like?

For most adults a good start is to combine moderate-intensity aerobic activity spread through the week with resistance exercise on at least two days. The World Health Organization recommends at least 150 minutes of moderate-intensity physical activity a week for adults; the NHS also advises muscle-strengthening activity on at least two days a week.

This table is an example. If you have been inactive for a long time or have a joint or heart problem, you need to start with shorter durations and build the plan with your doctor or an exercise specialist. In resistance exercise, put correct technique and regularity first, not the weight.

Which Resistance Exercises Can You Start With at Home?

You do not have to go to a gym for resistance exercise; an effective start can be made at home with body weight and simple equipment. It is important to do the movements slowly and with control and not to push through pain.

• Sit-to-stand from a chair: Works the leg and hip muscles; start with 8–12 repetitions.
• Wall push-ups: A safe start for the chest, shoulder and arm muscles.
• Rows with a resistance band: Strengthens the back muscles and supports posture.
• The bridge: Lifting the hips while lying on your back works the muscles around the hips and lower back.
• Calf raises: Useful for the calf muscles and for balance.

If you are over 50 or going through the menopause, resistance exercise becomes even more important because muscle and bone loss can already speed up. If you have a balance problem, do the movements near something to hold on to, and plan the programme with a physiotherapist or exercise specialist.

How Much Protein Should Someone Who Exercises Have While on the Injection?

Protein needs vary with body weight, age, exercise level and kidney health; so it is best to set your personal target with your dietitian. What matters is to spread protein evenly through the day rather than in one meal and to put a protein source in every meal even on days when appetite is low.

Eggs, yoghurt, strained yoghurt, kefir, cheese, chicken, fish, red meat and pulses are good options. If your appetite is very limited, eating the protein first, then the vegetables and the grains last lets you get the most from the meals you eat in small amounts. You can look at the article on how to calculate daily protein needs to work out your own need.

What Should You Eat Before and After Training?

While on the medicine, intense training on an empty stomach can cause dizziness and weakness, whereas training straight after a heavy meal can increase nausea. The most comfortable approach is a small, easily digested snack 1–2 hours before training and a meal containing protein afterwards.

• Before training (1–2 hours): Half a banana and a few spoonfuls of yoghurt, a slice of wholegrain bread with cheese, or a small bowl of oats cooked in milk.
• During training: Water in small sips; take care to make up fluid loss in long, sweaty workouts.
• After training: A plate with egg, a chicken salad, strained yoghurt and fruit, or lentil soup with ayran (Turkish salted yoghurt drink).

You can also find the general principles of eating before and after training in the article on eating before and after exercise.

What Should You Do If You Have Nausea, Weakness or Dizziness?

Nausea and weakness can be more common at the start of treatment and with dose changes. In these periods it is safer to reduce the intensity of exercise and to prefer walking and light movement to intense training.

• If you have dizziness, chest pain, palpitations or shortness of breath during exercise, stop straight away and see your doctor.
• If you have lost fluid through vomiting or diarrhoea, postpone training until your fluid balance has recovered.
• If you also take a diabetes medicine or insulin, remember that blood sugar can fall with exercise; plan measurements and snacks with your doctor.
• Do not eat fatty, heavy foods before training; they can increase nausea.

You can look at the article on eating to manage the side effects of weight-loss injections for eating advice on digestive complaints.

Your energy needs rise a little on exercise days. Even if your appetite is low, on training days you need to avoid skipping meals, add a snack if necessary and take notice of signs of tiredness. Constant exhaustion, disturbed sleep or not recovering for a long time after training can be a sign that you are not eating enough.

How Do You Protect Fluid and Electrolyte Balance?

Because the medicines can also reduce the feeling of thirst, fluid deficiency can develop easily in people who exercise. Practical measures are to spread water through the day, to drink a glass of water before and after training, and to make sure your urine stays pale.

In long and very sweaty exercise, options such as ayran, mineral water and vegetable soup can help balance the loss of electrolytes. Most people do not need sugary sports drinks for everyday exercise.

If you sit for long periods in the day, getting up and walking for a few minutes every hour is also an easy way to increase your total movement.

Why Should Exercise Continue After the Medicine Ends?

When the medicine is stopped, appetite returns and the risk of weight gain rises; in this period muscle mass and a regular habit of movement are the most important protectors. The exercise routine built up while using the medicine forms the foundation of the period afterwards.

I described this transition in the article on whether weight comes back when you stop weight-loss injections. If you are using the medicine under a doctor's care and would like a nutrition plan that fits with your training programme and takes protein and energy balance into account, we can work together within sports nutrition. Remember that results vary from person to person.

Sources

• WHO – Physical activity
• NHS – Physical activity guidelines for adults aged 19 to 64
• NIDDK – Prescription Medications to Treat Overweight & Obesity
• NHS – Tirzepatide

This article is for general information only; please consult your doctor and dietitian about your own situation.