0:00:02 > 0:00:06The River Thames. Britain's most iconic river.
0:00:06 > 0:00:09But it was never meant to be a 140-mile-long swimming pool.
0:00:09 > 0:00:14Until comedian David Walliams decided to swim it for Sport Relief.
0:00:14 > 0:00:17'I chose the Thames cos I thought it would be an amazing challenge.'
0:00:17 > 0:00:19Bye!
0:00:19 > 0:00:22I thought it would capture people's imaginations.
0:00:22 > 0:00:25Cos most people in the UK know the Thames, have seen it.
0:00:25 > 0:00:28And I know people like to see people off the TV suffer!
0:00:30 > 0:00:32And suffer he did.
0:00:33 > 0:00:38This is the inside story of what David went through.
0:00:38 > 0:00:41Your body's not meant to do this much swimming...day after day.
0:00:41 > 0:00:44Putting his body through agony...
0:00:45 > 0:00:50Testing his determination in eight days of incredible highs
0:00:50 > 0:00:52and terrible lows.
0:00:54 > 0:00:56- How you feeling? - Like I'm going to vomit.
0:00:56 > 0:00:59That is one very tired, sick man.
0:01:18 > 0:01:22David's challenge is as epic as it is daunting.
0:01:22 > 0:01:26He is aiming to swim a gruelling 140 miles down the Thames
0:01:26 > 0:01:29from rural Gloucestershire to Central London.
0:01:36 > 0:01:40David's eight-day challenge starts in rural Lechlade,
0:01:40 > 0:01:44in the heart of the Cotswolds, near to the source of the Thames.
0:01:44 > 0:01:46CHEERING
0:01:46 > 0:01:49"I'm a Lech-lady!" Very good! Thank you very much!
0:01:49 > 0:01:54- Wow! Another cake! That's beautiful!- Wow!
0:01:54 > 0:01:57To be honest, I'd be demoralised if no-one had come to see me.
0:01:57 > 0:02:00Come on, who's taking the picture?
0:02:00 > 0:02:03This is ultimately all about trying to raise money,
0:02:03 > 0:02:08and awareness. If no-one cared that I was going to get in and swim,
0:02:08 > 0:02:11the whole thing, for me, would be pointless.
0:02:12 > 0:02:14David's supermodel wife Lara
0:02:14 > 0:02:19and mum Kathleen are in Lechlade to see David start his big swim.
0:02:26 > 0:02:28As the crow flies,
0:02:28 > 0:02:31it's only 57 miles to Central London,
0:02:31 > 0:02:34but the way the Thames meanders means, to get there,
0:02:34 > 0:02:38David must swim 140 miles.
0:02:38 > 0:02:42To finish, David will have to overcome many hurdles.
0:02:42 > 0:02:44The Thames is full of debris,
0:02:44 > 0:02:46unpredictable currents
0:02:46 > 0:02:49but the immediate danger
0:02:49 > 0:02:52is the unseasonably cold temperature of the water.
0:02:56 > 0:02:59We know what water temperature is, it's 15 degrees centigrade.
0:02:59 > 0:03:03That's two degrees lower than the Channel. It's incredibly cold.
0:03:03 > 0:03:06He's going to have to survive that for 140 miles.
0:03:06 > 0:03:08The cold was always going to be a problem.
0:03:08 > 0:03:10David's choice to swim without a wetsuit
0:03:10 > 0:03:13has turned out to be the wrong decision.
0:03:13 > 0:03:17For the first hour or so, was just how cold it was,
0:03:17 > 0:03:21- and it was awful because it really puts you off.- It eats you.
0:03:21 > 0:03:25I couldn't think of anything else other than how cold it was.
0:03:25 > 0:03:27I could see you were blue on your back.
0:03:27 > 0:03:30That's cos I'm part Smurf!
0:03:30 > 0:03:35# Just keep on, keep on swimming
0:03:35 > 0:03:39# Just keep on, keep and swimming
0:03:39 > 0:03:43# Just keep on, keep on swimming
0:03:43 > 0:03:47# And don't look back any more. #
0:03:48 > 0:03:51- I'm a rock star.- Aren't you cold?
0:03:51 > 0:03:54I am quite cold, but sometimes I'll tell you a secret -
0:03:54 > 0:03:55I wee in my wetsuit.
0:03:55 > 0:03:58CHEERING Don't tell anyone!
0:03:58 > 0:04:03But sometimes I wee in it, and that warms me up.
0:04:03 > 0:04:05Best not to do it in your clothes now,
0:04:05 > 0:04:08cos it doesn't have the same effect!
0:04:08 > 0:04:11- I'm going to get back in. - Good luck!- Thanks a lot.
0:04:11 > 0:04:14APPLAUSE AND CHEERING
0:04:14 > 0:04:17The public are turning up in their droves to support David
0:04:17 > 0:04:23and give money to Sport Relief by texting a donation or giving cash.
0:04:23 > 0:04:28Three months before the swim, David went to Kisumu in Kenya,
0:04:28 > 0:04:30to see where some of the money will go.
0:04:30 > 0:04:33Of the 160,000 people who live in this town,
0:04:33 > 0:04:3620,000 are children sleeping rough.
0:04:36 > 0:04:39One little orphaned boy called Philip
0:04:39 > 0:04:41made a particularly big impression on David.
0:04:41 > 0:04:44- You've brought me here - this is where you sleep?- Yeah.
0:04:44 > 0:04:47Right here?
0:04:47 > 0:04:52- This one is ours.- So you all sleep together to keep warm?- Yeah.
0:04:52 > 0:04:57This is in the middle of two really, really busy, noisy roads.
0:04:57 > 0:05:00Is it safe here to sleep?
0:05:00 > 0:05:03Yeah, here is safe to sleep because there is security there.
0:05:03 > 0:05:07There's security there for the mall, so that's why you chose this place?
0:05:07 > 0:05:10Yeah, because of some comes to disturb us, someone goes to tell him.
0:05:10 > 0:05:15I couldn't imagine in a million years,
0:05:15 > 0:05:19anyone thinking that this is OK that these kids sleep like this.
0:05:19 > 0:05:23'When you're told that there are 20,000 kids on the streets in Kisumu,
0:05:23 > 0:05:27'it's hard to process that.
0:05:27 > 0:05:31'But when you meet them as individuals, it's much more affecting.
0:05:31 > 0:05:34'And that's one of the things that spurs you on.'
0:05:44 > 0:05:47David is two hours behind schedule.
0:05:47 > 0:05:49The freezing conditions have slowed him down,
0:05:49 > 0:05:54and the safety team are worried about the risks of him swimming in the dark.
0:05:54 > 0:05:57Trainer Greg goes in to pick up the pace.
0:05:57 > 0:05:58Greg's supporting and encouraging him.
0:05:58 > 0:06:01He's in a lot of pain right now.
0:06:01 > 0:06:03And he's trying to keep the pace,
0:06:03 > 0:06:07to keep him going at a pace which will get us through before darkness.
0:06:07 > 0:06:09APPLAUSE AND CHEERING
0:06:09 > 0:06:11It's so unbelievably gruelling.
0:06:11 > 0:06:16Not just swimming that distance, but also being that cold.
0:06:16 > 0:06:19I really don't like failing, and on the first day,
0:06:19 > 0:06:23being 2.5 miles behind was a real drag, and suddenly I was thinking,
0:06:23 > 0:06:27"We're not going to do this in eight days, it will be nine or ten days."
0:06:33 > 0:06:36Back in the Thames, day two is proving
0:06:36 > 0:06:38to be exhausting for David.
0:06:42 > 0:06:45ALL: David, David, David!
0:06:50 > 0:06:52When I heard that he was swimming, he inspired me
0:06:52 > 0:06:57and I feel happy that he's doing stuff for children who don't have much.
0:06:57 > 0:07:00He's got a lot of guts to swim all that way.
0:07:00 > 0:07:03- He's got strength. - He does deserve a break though.
0:07:03 > 0:07:07He's running out of time to get to the final stop at Abingdon.
0:07:08 > 0:07:11- WOMAN:- Well done, David, keep going!
0:07:20 > 0:07:23I'd been swimming for probably ten hours, I was really cold,
0:07:23 > 0:07:28and I suppose it's when you've been giving everything you've got,
0:07:28 > 0:07:29but it's just not been enough.
0:07:35 > 0:07:39Day three, and on top of exhaustion and muscle pain,
0:07:39 > 0:07:41David has been struck down by sickness.
0:07:49 > 0:07:52I just don't think I can eat any more. I just feel so sick.
0:07:52 > 0:07:55Get some fluid down then for me.
0:07:55 > 0:07:58And take that vitamin, too, get that down you.
0:07:58 > 0:07:59And it is so hot in here,
0:07:59 > 0:08:04it might be worth going outside for a little wander.
0:08:04 > 0:08:09The medical team think David has swallowed bacteria
0:08:09 > 0:08:13washed into the river after yesterday's torrential rain.
0:08:15 > 0:08:19When you're feeling really sick, what you should be doing
0:08:19 > 0:08:24is just lying in bed, with your mum bringing you Lucozade and Rich Tea biscuits.
0:08:24 > 0:08:29At no point does your mum say what you should really do is go swimming in a river.
0:08:32 > 0:08:34- How are you feeling? - Just like I'm going to vomit.- Do you?
0:08:34 > 0:08:39That is one very tired, sick man.
0:08:40 > 0:08:43And we're squeezing everything we can out of him at the moment.
0:08:43 > 0:08:46- Are you worried about him, Greg? - Yeah, seriously worried,
0:08:46 > 0:08:49because he's not a guy that gives up.
0:08:49 > 0:08:51And he's not feeling good.
0:08:51 > 0:08:56'But I just thought, if I CAN put one arm in front of another,
0:08:56 > 0:09:00'then I can get nearer to the finish line.
0:09:00 > 0:09:03'And as long as I could still do that,
0:09:03 > 0:09:06'I was still achieving something.'
0:09:06 > 0:09:08APPLAUSE
0:09:09 > 0:09:13- WOMAN:- Come on, David! Well done, David!
0:09:14 > 0:09:16Hello!
0:09:18 > 0:09:20My stomach feels totally churned up.
0:09:20 > 0:09:23David is given an anti-sickness tablet
0:09:23 > 0:09:25to try and settle his stomach.
0:09:25 > 0:09:27- Just leave it there.- OK.
0:09:27 > 0:09:29Anything running through your mind at all?
0:09:29 > 0:09:32- I can't hear you.- Huh? - I can't hear you.- OK!
0:09:32 > 0:09:36So I can say whatever I like now?
0:09:36 > 0:09:38Thank you.
0:09:57 > 0:10:00The anti-vomiting tablet starts to kick in.
0:10:00 > 0:10:02- CHANTING:- David! David! David! David! David!
0:10:02 > 0:10:06I thought I'd have to at least take this day out to get better,
0:10:06 > 0:10:08but Greg was determined that we could push on.
0:10:08 > 0:10:11But I don't think I could have done it without that pill.
0:10:11 > 0:10:13I didn't feel good,
0:10:13 > 0:10:16but at least I didn't feel like I was going to throw up.
0:10:16 > 0:10:21David pushes on into the afternoon of day three.
0:10:24 > 0:10:26Hello. Do you want to give me that baby?
0:10:26 > 0:10:29- Oh, I'd love to.- Yes?
0:10:31 > 0:10:33- A beautiful baby.- Thank you. - Well, nice to meet you.
0:10:33 > 0:10:35LAUGHTER
0:10:35 > 0:10:37I'll take that!
0:10:37 > 0:10:40- Bye! - ALL: Bye!
0:10:40 > 0:10:42CHEERING
0:10:46 > 0:10:49BOAT HORNS HONK
0:10:51 > 0:10:53'It's been a day of two halves.'
0:10:53 > 0:10:56There'll be plenty of people watching, saying, "Why didn't Greg
0:10:56 > 0:11:00"stop him from getting in the water? Why did he make him get in the water?"
0:11:00 > 0:11:03But it's because sometimes you've just got to push through it.
0:11:30 > 0:11:32David's Thames tummy from yesterday
0:11:32 > 0:11:35means he is four miles behind schedule.
0:11:35 > 0:11:37Today, he has to swim flat-out
0:11:37 > 0:11:41to Reading, 18 miles away.
0:11:42 > 0:11:47- I knew these middle days would be the hardest.- Yeah.
0:11:47 > 0:11:52It's nice there are still people out to support me. I'm just very stiff.
0:11:52 > 0:11:56- Yeah?- Your body's not meant to do this much swimming in one day,
0:11:56 > 0:11:58day after day.
0:12:11 > 0:12:14David pushes on towards Reading, the half-way mark,
0:12:14 > 0:12:18and the crowds seem to be getting bigger and bigger.
0:12:18 > 0:12:22It's really taken off and captured people's imaginations.
0:12:22 > 0:12:24But I'm really glad because it's been really hard work.
0:12:24 > 0:12:27I must say, if I'd done all this and no-one cared,
0:12:27 > 0:12:30I would have felt a bit stupid, so I'm glad.
0:12:30 > 0:12:32But it's been bigger than I thought.
0:12:32 > 0:12:35You know, people have wanted to come out and see me.
0:12:35 > 0:12:40It feels like a real sort of British event.
0:12:40 > 0:12:44People of Reading! CHEERING
0:12:44 > 0:12:47This is David Walliams off the TV.
0:12:47 > 0:12:49LAUGHTER AND CHEERING
0:12:49 > 0:12:52Thank you so much for coming out to support me
0:12:52 > 0:12:55and this fantastic cause, Sport Relief.
0:13:08 > 0:13:11CHEERING
0:13:12 > 0:13:15We were running out and we were thinking, "Are we going to see him?
0:13:15 > 0:13:19And then, all of a sudden, you just hear this massive cheer
0:13:19 > 0:13:23- "He's round the corner!"- Yeah, yeah. - Brilliant. Absolutely brilliant.
0:13:23 > 0:13:25It was quite remarkable.
0:13:25 > 0:13:29I know he swam the Channel, which is a flipping good thing to have done.
0:13:29 > 0:13:32Amazing. I must say, he keeps going all the time with Delhi belly
0:13:32 > 0:13:35or whatever he's got, Thames trouble.
0:13:35 > 0:13:38When you live in the home counties and not in the big city,
0:13:38 > 0:13:41you're not normally part of things like this. It's great to be
0:13:41 > 0:13:43more out in the sticks and be part of a challenge...
0:13:43 > 0:13:46A little village like Shiplake, this is exciting.
0:13:46 > 0:13:49We'll be talking about this for a long time.
0:13:49 > 0:13:52I have to say, my kids thought that we were coming out
0:13:52 > 0:13:54to support Robbie Williams, so...(SNORTS)
0:13:54 > 0:13:56Slight disappointment on their part then.
0:13:59 > 0:14:01Keep going!
0:14:06 > 0:14:08- Oh, what's that?- Alcohol.
0:14:08 > 0:14:12David has fully recovered from his sickness, but is still in pain.
0:14:12 > 0:14:16The rubbing from the wetsuit has stripped the skin
0:14:16 > 0:14:17off the back of his neck.
0:14:17 > 0:14:19Argh! Arrgh!
0:14:21 > 0:14:25Have you noticed, David? I'm not crying like a baby. Here, look.
0:14:25 > 0:14:27Hard, mate. Ah, god!
0:14:27 > 0:14:33Ooh! That really is hurting. Holy schmoly!
0:14:33 > 0:14:37- Perfectly good reaction. - HE LAUGHS
0:14:37 > 0:14:39That really does hurt, doesn't it?
0:14:39 > 0:14:41Yeah. I mean, it's worse than what we had,
0:14:41 > 0:14:46the original pain. This new pain that you create.
0:14:46 > 0:14:47CHEERING
0:14:47 > 0:14:51At least the ever increasing crowds keep coming.
0:14:51 > 0:14:53I got into the habit of thinking,
0:14:53 > 0:14:54"Well, if there's people, I'll wave."
0:14:54 > 0:14:58You know, because you'd occasionally get them at bridges and places.
0:14:58 > 0:15:00And then it became like certain places,
0:15:00 > 0:15:04it was just all people along the side and then I had to just...
0:15:04 > 0:15:06I was thinking, "Right, who are you going to wave to?"
0:15:06 > 0:15:08"You've got to swim. It can't all be waving."
0:15:08 > 0:15:11So I think, "OK, someone with a sign."
0:15:11 > 0:15:14They get a wave because they've put some work in
0:15:14 > 0:15:18to that sign. OK, kids get a wave.
0:15:18 > 0:15:20And then someone with a flag gets a wave
0:15:20 > 0:15:23and I'm like, "Oh, no. That's still too many people."
0:15:23 > 0:15:26I would swim for a bit and then wait and then wave.
0:15:26 > 0:15:29And then Greg would tell me get a move on and stop waving!
0:15:29 > 0:15:32How far is he?
0:15:35 > 0:15:38I think you can hear from the cheers of the crowd on the other bank
0:15:38 > 0:15:42that David Walliams is just round the bend of the Thames.
0:15:42 > 0:15:44Marlow was incredible,
0:15:44 > 0:15:48because I was swimming in to be live on TV,
0:15:48 > 0:15:50so there were probably even more people there
0:15:50 > 0:15:53because they heard about it through The One Show.
0:15:53 > 0:15:58And there was synchronised swimmers, there was Angela Rippon.
0:15:58 > 0:16:02And his wife, obviously the first person to greet him
0:16:02 > 0:16:04and give him a big kiss.
0:16:04 > 0:16:07- I know, sorry. My wife has to come first.- Of course she has.
0:16:07 > 0:16:09David, you must be so pleased to get your feet on dry land.
0:16:09 > 0:16:14Oh, definitely. What an amazing turn out of people in Marlow.
0:16:18 > 0:16:22'And then I was taken round in a boat to wave at people.
0:16:22 > 0:16:26'Never in my life has waving in itself been enough.'
0:16:26 > 0:16:28I've had to sort of do something,
0:16:28 > 0:16:31'like say something funny or dress up.'
0:16:31 > 0:16:34I'll have my own little Dave-mobile soon, for waving at people.
0:16:34 > 0:16:36'It was incredible.'
0:16:36 > 0:16:39I've never had that before
0:16:39 > 0:16:41and it was really overwhelming.
0:16:48 > 0:16:52The next stretch of David's challenge is from Marlow to Windsor.
0:16:52 > 0:16:55London is almost in touching distance.
0:16:55 > 0:17:00It's a 17 mile swim, so he will need lots of energy.
0:17:00 > 0:17:03David's fans continue to flock to the banks,
0:17:03 > 0:17:08but one in particular gets a bit too close for comfort.
0:17:08 > 0:17:10I was swimming along and then this...
0:17:10 > 0:17:13I heard this plop behind me and I thought,
0:17:13 > 0:17:16"Ooh, has somebody got in the water?" And then I saw it was a dog.
0:17:16 > 0:17:20I love dogs and I sort of doggy-paddled along with it.
0:17:20 > 0:17:22That was sweet.
0:17:23 > 0:17:27Then the dog tried to get out of the water and couldn't,
0:17:27 > 0:17:30and the owner tried to pull it
0:17:30 > 0:17:32by the sort of harness lead thing.
0:17:32 > 0:17:34And then that broke,
0:17:34 > 0:17:38so then I swam back and pushed the dog up onto the bank.
0:17:38 > 0:17:39Yay!
0:17:39 > 0:17:42CHEERING
0:17:45 > 0:17:48Yeah, David Walliams saved my dog.
0:17:48 > 0:17:50- No, I didn't expect that! - HE LAUGHS
0:17:50 > 0:17:54# Well, I won't back down
0:17:54 > 0:17:58# No, I won't back down
0:17:58 > 0:18:03# You can stand me up at the gates of hell
0:18:03 > 0:18:06# But I won't back down. #
0:18:06 > 0:18:10Can I ask you some questions?
0:18:10 > 0:18:12David?
0:18:12 > 0:18:14Can I ask you some questions?
0:18:15 > 0:18:19David! You rude man!
0:18:19 > 0:18:22Could I ask you some questions? Oi!
0:18:23 > 0:18:25You! Hello!
0:18:27 > 0:18:30- What?- Would you please give me some attention.- What?
0:18:30 > 0:18:33- I just wanted to chat to you for a minute.- Well, I can't. I'm swimming.
0:18:33 > 0:18:36- Is there going to be any more Little Britain?- No!
0:18:36 > 0:18:38- Right, well carry on.- OK, thank you.
0:18:43 > 0:18:44I'm doing OK.
0:18:44 > 0:18:48I mean, it's hard, I'm finding it tiring, but I'm going to keep going.
0:18:48 > 0:18:53It's just knowing all these people have come out to support me.
0:18:53 > 0:18:55It got bad. We left the lock
0:18:55 > 0:18:59about seven, eight minutes ago.
0:18:59 > 0:19:02I think about two minutes in, it got really scary.
0:19:02 > 0:19:05But I'm just going to keep going. I'm not going to give up.
0:19:05 > 0:19:08I've got this idiot in front of me who keeps getting in the way.
0:19:08 > 0:19:10I mean, I could do without that.
0:19:22 > 0:19:24CHEERING
0:19:32 > 0:19:35It was fantastic. I actually cried.
0:19:35 > 0:19:36Yeah.
0:19:36 > 0:19:40Because to see all these people cheering him...
0:19:40 > 0:19:42Yeah.
0:19:54 > 0:19:556.00am.
0:19:57 > 0:20:00Still dark, but swim we must.
0:20:02 > 0:20:05Today's goal is to get to Teddington lock,
0:20:05 > 0:20:08marking the end of the non-tidal Thames.
0:20:08 > 0:20:11It is 24 miles away.
0:20:11 > 0:20:14David has never swam that far before in one day.
0:20:16 > 0:20:19In the really dark periods, you know,
0:20:19 > 0:20:23when Greg says dig deep after you've already swum 20 miles,
0:20:23 > 0:20:27it's good to remember why you're doing it and what good it can do.
0:20:27 > 0:20:29I've done loads of fun things as well,
0:20:29 > 0:20:34you know for Comic Relief, sketches and things like that, but there's...
0:20:34 > 0:20:38But the effect of doing something hard just seems greater to me.
0:20:38 > 0:20:40It seems to resonate more with people.
0:20:42 > 0:20:45- Hello, Mum. How are you? - Hello, darling.- How are you?
0:20:45 > 0:20:47- I'm all right, how are you? - Yeah, OK!
0:20:47 > 0:20:51'But it's amazing, I think, you know, the amount of people.'
0:20:51 > 0:20:57- If people respond to you, you do better.- Perform better, yeah.- Yeah.
0:20:57 > 0:20:59You said that when you first did a school play
0:20:59 > 0:21:04and you started to be a bit... Act up a bit that you thought, "This is great."
0:21:04 > 0:21:06It's called showing off!
0:21:06 > 0:21:07SHE LAUGHS
0:21:07 > 0:21:13I don't think I've ever been quite so proud of him as what he's achieved this week.
0:21:13 > 0:21:16I know his father would've been so proud.
0:21:24 > 0:21:26CHEERING, APPLAUSE AND HONKING
0:21:26 > 0:21:29David has already swum the equivalent of the Channel,
0:21:29 > 0:21:3221 miles, but still has three to go.
0:21:32 > 0:21:35But conditions are getting worse due to the after-affects
0:21:35 > 0:21:38of a hurricane that has swept in from the Atlantic.
0:21:38 > 0:21:43The point is now, he is...physically exhausted.
0:21:43 > 0:21:46He's done, like, 124 miles by the time he finishes today.
0:21:46 > 0:21:48Come on, David!
0:21:48 > 0:21:53You needed to get to Teddington Lock before it got dark.
0:21:53 > 0:21:56I swam about 20 miles and then I was told that the light was fading.
0:21:56 > 0:22:00It was just about to get dark and could I speed up?!
0:22:00 > 0:22:03Which, when you've swum 20 miles and someone says, "Can you speed up?"
0:22:03 > 0:22:05It's like, "I'll TRY!"
0:22:05 > 0:22:09You've got to really drive it now, cos we haven't got much light left. You've really got to push it.
0:22:09 > 0:22:16- Come on!- Whoo! Whoo! Come on, David!
0:22:18 > 0:22:22'I just thought in my head, "Right, how fast would you swim'
0:22:22 > 0:22:24"if a shark was following you?"
0:22:24 > 0:22:28I thought, "It'd be quite fast!" So I just thought of that.
0:23:00 > 0:23:01It's the last day.
0:23:01 > 0:23:04After more than 70 hours of relentless swimming,
0:23:04 > 0:23:09David has 16 miles to go.
0:23:09 > 0:23:10I CAN believe it's the last day
0:23:10 > 0:23:12because I've been swimming for seven days
0:23:12 > 0:23:17for 125 miles and I am ready for it to end.
0:23:17 > 0:23:22So you go, "It's only 15 miles to go."
0:23:22 > 0:23:2415 miles is a long way to swim!
0:23:24 > 0:23:30How many people have swum 15 miles in a day? So...I can believe it.
0:23:30 > 0:23:34My arms can believe it, my neck can believe it, my back...
0:23:37 > 0:23:40I mean, it's just constant, constant pain now.
0:23:46 > 0:23:50Nobody should ever swim in this stretch of the Thames.
0:23:50 > 0:23:54It's far too hazardous. A law is being passed to ban it.
0:23:54 > 0:23:57David is only able to do this because of the safety boats
0:23:57 > 0:23:58that are watching him.
0:24:00 > 0:24:03Getting in after Teddington Lock, I was definitely more nervous
0:24:03 > 0:24:06cos if you stand on a bridge in central London
0:24:06 > 0:24:07and look at the river,
0:24:07 > 0:24:11there's no way you want to get in there and swim.
0:24:11 > 0:24:14It's travelling really fast, it's really wide.
0:24:14 > 0:24:18The water's brown and so...
0:24:18 > 0:24:21I really was quite scared even though I was at the end.
0:24:21 > 0:24:24I thought, "This is a much more hostile environment to swim in."
0:24:24 > 0:24:28Once the tide turns it'll be too strong to swim against,
0:24:28 > 0:24:32and he will have to get out and wait. It's not over yet.
0:24:32 > 0:24:34I'm just thinking I hope nothing goes wrong,
0:24:34 > 0:24:38I hope no-one drops a brick on me from a bridge or...
0:24:38 > 0:24:41You know, I drown or the tide changes
0:24:41 > 0:24:46or Godzilla comes out of the Thames or something cos then it's all over!
0:24:46 > 0:24:50Stay nice and tight on that right, mate, OK? So straight in...
0:24:50 > 0:24:53'So I'm just praying that everything just goes totally smoothly.'
0:25:04 > 0:25:08Eight painful and exhausting days.
0:25:12 > 0:25:15Swimming through seven long counties.
0:25:28 > 0:25:30One dog saved.
0:25:32 > 0:25:35Over 68,000 calories burned.
0:25:35 > 0:25:42111,352 strokes.
0:25:43 > 0:25:48And a sea of people turning up to see the fastest man ever
0:25:48 > 0:25:52to swim 140 miles of the River Thames.
0:25:52 > 0:25:54CHEERING
0:25:59 > 0:26:02Sometimes people write in articles, why on earth is he doing it?
0:26:02 > 0:26:04I know exactly why I'm doing it
0:26:04 > 0:26:08because I've seen how the money raised through Comic Relief
0:26:08 > 0:26:11and Sport Relief helps people around the world and the people I met
0:26:11 > 0:26:15and especially Philip, the homeless boy in Kenya.
0:26:15 > 0:26:20That's my motivation. There is no other motivation for this.
0:26:29 > 0:26:32I mean, it's amazing.
0:26:32 > 0:26:35He has raised, without a doubt, in excess of £1 million.
0:26:35 > 0:26:40He is the most remarkable man. Tremendous.
0:26:40 > 0:26:43# We've got open arms
0:26:43 > 0:26:48# For broken hearts
0:26:48 > 0:26:53# Like yours, my boy
0:26:53 > 0:26:56# Come home again. #
0:26:56 > 0:27:00- CHANTING:- David, David, David, David, David!
0:27:06 > 0:27:08CHEERING
0:27:08 > 0:27:12- # Everyone's here - # We've got open arms
0:27:12 > 0:27:14# Everyone's here. #
0:27:14 > 0:27:17So proud that he's achieved this,
0:27:17 > 0:27:20- I don't know where he gets all the strength from.- No.
0:27:20 > 0:27:22Somewhere deep down inside he finds it.
0:27:22 > 0:27:27# Everyone's here. #
0:27:30 > 0:27:33And it's not too late to get involved in Sport Relief.
0:27:33 > 0:27:38If you've been inspired by David's challenge, why not take part in the Sport Relief Mile.
0:27:38 > 0:27:42And don't forget to watch this evening's programme, starting at 7pm on BBC1.
0:27:51 > 0:27:55Subtitles by Red Bee Media Ltd