Boxing burns more calories than any other sport, according to new research.
You burn 800 calories over an hour in the ring - making it the most effective sport for weight loss.
Squash was the second most effective sport for dieting at 748 calories an hour.
Sex, in comparison, burns 200 calories an hour if you are a man (the same as yoga) and 138 for a woman (similar to the energy expended walking the dog!).
Statistically men tend to be more active during sex than women - which explains why their calorie burn is higher.
The results are from a new survey by the health and wellbeing brand Forza Supplements which measured the calorie burning effectiveness of our 50 most popular sports and activities.
Every popular sport and activity was measured from walking the dog (136 calories an hour) to cleaning the house (102 calories) to watching TV (0 calories on the sofa, 20 calories if you are standing up).
Boxing was the most effective because it is super intense interval training and involves engaging multiple muscle groups.
Squash was highly effective because the rallies tend to be longer than in other racket sports and the break between points is shorter than in tennis. The almost constant running builds muscular strength and endurance in the lower body while the lunges, twists and turns increase flexibility in the back and abdomen
Rowing came third at 740 calories but only if you are doing it on a river or a lake - the calorie burn drops to 440 calories if this is on a rowing machine at the gym.
Road running at a medium or fast pace came fourth at 700 calories an hour - much effective than doing it on a treadmill at a gym (580 calories in 10th place).
Swimming came in fifth but only if you do front crawl or butterfly - 680 calories an hour. The more sedate breast stroke burned just 408 calories (15th place).
Popular team sports were next best for calorie burning with rugby (614 calories an hour) just beating football (612 calories) due to its heightened physicality.
In eighth place was fast road cycling at 604 calories an hour - much more effective than a gym exercise bike (540 calories).
An hour at the gym doing various cardio activities, press-up, push-ups and weights was ninth, burning 590 calories, but only 380 calories if you just stick to weights.
Hockey was next best for weight loss at 478 calories an hour, followed by basketball (475 calories) and tennis (470 calories).
Cricket (if you are batting or bowling) was best of the more sedate sports (272 calories), followed by golf (236 calories, as long as you are walking and carrying your clubs and not using a buggy) and table tennis (204 calories).
Forza Supplements managing director Lee Smith said: "We just hope that these figures encourage more people to get active to combat our growing obesity crisis.
"Boxing is terrific for weight loss because it is the ultimate full body work-out with intense bursts of activity - just like the very best interval training.
"The figures show that any activity is better than lounging in front of the TV and, if you are going to do that, at least do it standing up and burn 20 calories an hour.
"There are lots of fun ways to burn calories particularly when you are on holiday - snorkelling at the beach (274) burns more calories than badminton (240) or a round of golf (236).
"Sex is a great way to burn off calories, particularly if you are a man because statistics show they expend 44% more energy than women during typical lovemaking.
"An hour of sex for a man burns as many calories as an hour of yoga, but sex for an hour for a woman is roughly the same calorie burn as walking the dog!"
Forza Supplements has developed weight loss and wellbeing plans for a number of British stars including Britain's Got Talent winner Richard Hadfield, formerly of the male singing group Collabro.
Its Shake It Slim supplement is one the UK's best-selling meal replacement drinks.
50 most popular activities for weight loss - with calories burned in an hour by a person weighing 11st (70kg)
1. Boxing 800 calories burned in an hour
2. Squash 748
3. Rowing (on a lake or river) 740
4. Road running at a fast or medium past 700
5. Swimming - front crawl or butterfly 680
6. Rugby 614
7. Football 612
8. Road cycling fast 604
9. Gym exercise (weights and cardio) 590
10. Running on a treadmill 580
11. Hockey 478
12. Basketball 475
13. Tennis 470
14. Rowing machine 440
15. Breaststroke or backstroke 408
16. Vigorous walking with a backpack 406
17. Weights at gym 340
18. Pilates 320
19. Ballroom dancing fast - quick-step, Charleston 306
20. Snorkelling 274
21. Cricket 272
22. Skateboarding 270
23. On piste downhill ski-ing 270
24. Trampolining 252
25. Volleyball 240
26. Badminton 238
27. Golf 236
28. DIY - sanding, painting, sawing 235
29. Walking to work 207
30. Gardening 206
31. Table tennis 204
32. Horse riding 202
33. = Sex for a man 200
33. = Yoga 200
35. Fishing from a riverbank (standing) 200
36. Volleyball 198
37. Sex for a woman 138
38. Walking the dog 136
39. Ballroom dancing slow - waltz 135
40. Household chores - dusting, vacuuming, ironing 102
41. Bird watching 101
42. Playing the piano 100
43. Washing dishes 88
44. Shopping 86
45. Cooking 69
46. Driving a car 68
47. Having a bath 35
48. Typing 34
49. Watching TV standing up 20
50. Watching TV on the sofa 0