Fitness trackers are practical: they measure heart rate, count steps, record activity and, once synced with a phone, estimate how much energy you burned. One enthusiastic technical diver decided to use his tracker to compare his favourite sport with cycling. It was not a scientific study, just an experiment by one diver with one wristband – but the results are interesting and match what many divers feel after a long day in the water.
Cycling versus diving
The bike ride
First he went for a ride. He pedalled for 1 hour and 24 minutes, covered 25 kilometres and, according to the tracker, burned 1,295 kcal. As he put it, the ride was at the edge of his comfort zone – nothing he could not handle, but certainly no leisurely spin.
The dive day
The next day was a dive to 10 metres in water at 14 °C. Before he even got into the water, he had to:
- prepare and assemble four bailout cylinders,
- carry them, two at a time, about 50 metres to the water,
- walk back to the car for his suit and the rest of his equipment,
- carry everything to the entry point again.
He then spent almost two hours underwater – 115 minutes – practising emergency drills including cylinder swaps. From the start of preparations to the final packing of his equipment, he was active for 3 hours and 42 minutes.
What the tracker showed
The diver repeated the experiment the following day with a slightly shorter dive of 87 minutes. Comparing both days, he estimated that each minute of diving cost him about 6.5 kcal on average.
Per minute, diving burned less energy than cycling. Over the whole day, however, the picture changed: the long dive including all the preparation and carrying of equipment burned considerably more energy than a solid bike ride. And perhaps the most interesting finding – while he felt exhausted after cycling, he experienced the dive as a pleasant, relaxing activity.
How accurate is a tracker underwater?
Fitness trackers estimate energy expenditure from heart rate and movement. In water, under a drysuit cuff and with little arm movement, these estimates are only rough. Take the numbers as an illustration rather than an exact measurement – the overall trend is what matters.
Why diving takes so much energy
Even without laboratory precision, the results make sense. Diving is energy-demanding for several reasons:
- Cold – water draws heat away from the body many times faster than air. Even in a wetsuit or drysuit, the body works hard to stay warm, especially on long dives.
- Water resistance – moving through water takes much more effort than moving on land.
- Heavy equipment – carrying, assembling and handling cylinders and weights is real physical work.
- Concentration – planning, monitoring and reacting to situations also demand energy and add to fatigue.
Practical tips for long dive days
- Stay warm. Good thermal protection saves energy and makes long decompression more comfortable. A drysuit with suitable undergarments is the standard for cold water – see our dry suits.
- Drink enough. Immersion increases fluid loss, and dehydration is one of the factors associated with decompression stress. Drink regularly before and between dives.
- Eat between dives. Plan proper meals and snacks so you do not start the second dive on an empty tank.
- Carry equipment sensibly. Use a trolley or ask a buddy for help, and take breaks between trips to the water. Cylinders and accessories can be found in our tanks and accessories category.
- Stay fit. General fitness makes carrying equipment easier and helps you handle demanding dives with a reserve.
Frequently asked questions
Does diving burn more calories than cycling?
Per minute, usually not. But a long technical dive including preparation, carrying equipment and time in cold water can add up to more energy over the whole day than a typical bike ride.
Why am I so hungry after diving?
Your body has spent energy staying warm, moving through the water and handling heavy equipment. Hunger after a dive is a normal response – plan a proper meal after longer dives.
Can I rely on my fitness tracker underwater?
Only as a rough guide. Heart-rate sensors on the wrist are less accurate in water and under a suit cuff, so the calorie figures are estimates.
What to take away
For divers, this is good news. Their hobby is not only a journey into another world, but also a solid workout. If you are looking for an activity that combines adventure, relaxation and real physical effort, diving may be exactly the right choice. And the next time you are sweating while carrying cylinders or squeezing into your suit, remember that it is an excellent training session – just far more fun than an hour in the gym. If you want to take diving further, read our guide on how to get started with technical diving.